Ne pas entreposer ni uliser dessence ou ni dautres vapeurs ou liquides inammables à proximité de
cet appareil ou de tout autre appareil.
QUE FAIRE SI VOUS SENTEZ UNE ODEUR DE GAZ :
Ne pas tenter dallumer dappareil.
Ne touchez à aucun interrupteur ; ne pas vous servir des téléphones se trouvant dans le bâment.
Appelez immédiatement votre fournisseur de gaz depuis un voisin. Suivez les instrucons du fournisseur.
Si vous ne pouvez rejoindre le fournisseur, appelez le service des incendies.
Linstallaon et lentreen doivent être assurés par un installateur ou un service dentreen qualié ou
par le fournisseur de gaz.
Do not store or use gasoline or other ammable vapors and liquids in the vicinity of this or any other appliance.
WHAT TO DO IF YOU SMELL GAS:
Do not try to light any appliance.
Do not touch any electrical switch; do not use any phone in your building.
Immediately call your gas supplier from a neighbors phone. Follow the gas suppliers instrucons.
If you cannot reach your gas supplier, call the re department.
Installaon and service must be performed by a licensed professional.
This enre manual must be le for the consumer.
The consumer must read and refer to this manual for
proper operaon and to maintain the water heater.
If the informaon in these instrucons is not followed exactly, a re or explosion may result
causing property damage, personal injury or death.
WARNING
READ ALL OF THE INSTRUCTIONS THOROUGHLY BEFORE INSTALLING OR OPERATING THIS WATER HEATER.
This manual provides informaon on the installaon, operaon, and maintenance of the water heater. For proper
operaon and safety, it is important to follow the instrucons and adhere to the safety precauons.
A licensed professional must install the water heater according to the exact instrucons on pages 4-20.
The consumer must read the enre manual to properly operate the water heater and to have regular maintenance
performed.
Outdoor Tankless Water Heater
Installaon and Operaon Manual
FOR OUTDOOR APPLICATIONS ONLY
V53De ................... REU-AM1620WD-US
Full-length French and Spanish versions
available online at rinnai.us
Place
Model/Serial #
Label Here
Located in Manual Bag
Assurez-vous de bien suivre les instrucons données dans cee noce pour
réduire au minimum le risque dincendie ou dexplosion ou pour éviter tout
dommage matériel, toute blessure ou la mort.
AVERTISSEMENT
ANSI Z21.10.3 CSA 4.3
Low Lead Content
NSF/ANSI 372
2 V53De Manual
Table of Contents
This is the safety alert symbol. This symbol alerts you to potenal hazards that can kill or hurt you
and others.
Indicates an imminently hazardous situaon which, if not avoided, will result in death or
serious injury.
Indicates a potenally hazardous situaon which, if not avoided, could result in death or
serious injury.
Indicates a potenally hazardous situaon which, if not avoided, could result in minor or
moderate injury. It may also be used to alert against unsafe pracces.
DANGER
CAUTION
WARNING
Table of Contents ..................................................... 2
Safety Behaviors and Pracces for the
Consumer and Installer ............................................ 3
Installaon Instrucons
(for the licensed professional) .............................. 4
Prepare for Installaon ...................................... 5
Determine Installaon Locaon ........................ 5
Water Quality .................................................... 5
Checklist to Determine Installaon Locaon .... 8
Freeze Protecon .............................................. 8
Mount to Wall ................................................... 8
Remove the Front Panel .................................... 9
Installaon of Plumbing ..................................... 9
Checklist for Plumbing ..................................... 11
Installaon of Gas Supply ................................ 11
Connect Electricity ........................................... 13
Adjust for High Altude ................................... 13
Checklist for Gas and Electricity ...................... 13
Installaon of Temperature Controller ........... 14
Mounng the Controller ........................................ 15
Final Checklist ......................................................... 16
Technical Data ........................................................ 17
Specicaons ................................................... 17
Dimensions ....................................................... 18
Pressure Drop and Water Flow Curves ............ 19
Ladder Diagram ................................................ 20
Operaon Instrucons ....................................... 21
Consumer Operaon Guidelines for the
Safe Operaon of your Water Heater .............. 22
How to Use the Temperature Controller ......... 23
How to Set the Temperature ........................... 24
Diagnosc Codes .............................................. 27
Required Maintenance..................................... 29
Freeze Protecon and Winterizing ........... 30
Flushing the Heat Exchanger ..................... 31
Manual Draining of the Water Heater ...... 32
Limited Warranty .................................................... 33
Important Safety Informaon
Safety Denions
NOTICE: Rinnai somemes shares customer contact informaon with businesses that we believe provide
products or services that may be useful to you. By providing this informaon, you agree that we can
share your contact informaon for this purpose. If you prefer not to have your informaon shared with
these businesses, please contact customer service and ask not to have your informaon shared. We
will however, connue to contact you with informaon relevant to the product(s) you registered and/
or you account with us.
If you have any quesons or feel that the manual is incomplete contact Rinnai at 1-800-621-9419.
V53De Manual 3
CAUTION
BURN HAZARD. Hot exhaust and exhaust outlet
may cause serious burns. Keep away from water
heater unit. Keep small children and animals away
from unit.
Hot water outlet pipes leaving the unit can be hot
to touch. In residenal applicaons, insulaon
must be used for hot water pipes 36” or less
(height) from the oors due to burn risk to children.
Safety Behaviors and Pracces for the Consumer and Installer
Before operang, smell all around the appliance
area for gas. Be sure to smell next to the oor
because some gas is heavier than air and will sele
on the oor.
Keep the area around the appliance clear and free
from combusble materials, gasoline, and other
ammable vapors and liquids.
Combusble construcon refers to adjacent walls
and ceiling and should not be confused with
combusble or ammable products and materials.
Combusble and/or ammable products and
materials should never be stored in the vicinity of
this or any gas appliance.
Always check the water temperature before
entering a shower or bath.
To protect yourself from harm, before performing
maintenance:
Turn o the electrical power supply by
unplugging the power cord or by turning o the
electricity at the circuit breaker. (The
temperature controller does not control the
electrical power).
Turn o the gas at the manual gas valve, usually
located immediately below the water heater.
Turn o the incoming water supply. This can be
done at the isolaon valve immediately below
the water heater or by turning o the water
supply to the building.
WARNING / AVERTISSEMENT
Use only your hand to push in or turn the gas
control knob. Never use tools. If the knob will not
push in or turn by hand, do not try to repair it; call a
licensed professional. Force or aempted repair
may result in a re or explosion.
Do not use this appliance if any part has been under
water. Immediately call a licensed professional to
inspect the appliance and to replace any part of the
control system and any gas control which has been
under water.
(Nulisez pas cet appareil sil a été plongé dans
leau, même parellement. Faites inspecter
lappareil par un technicien qualié et remplacez
toute pare du système de contrôle et toute
commande qui ont été plongés dans leau).
Do not use substute materials. Use only parts
cered with the appliance.
Should overheang occur or the gas supply fail to
shut o, turn o the manual gas control valve to the
appliance.
(En cas de surchaue ou si lalimentaon en gaz ne
sarrête pas, fermez manuellement le robinet darrêt
de ladmission de gaz).
Do not adjust the Dip switch unless specically
instructed to do so.
Do not use an extension cord or an adapter plug
with this appliance.
Any alteraon to the appliance or its controls can be
dangerous and will void the warranty.
WARNING / AVERTISSEMENT
California law requires the following Proposion 65 warning to be provided:
This product can expose you to chemicals including lead, lead compounds and carbon bisulde which are known
to the State of California to cause cancer, birth defects or other reproducve harm. For more informaon, visit
www.P65Warnings.ca.gov.
4 V53De Manual
It is recommended that a licensed professional install
the appliance, inspect it, and leak test it before use.
The warranty may be voided due to any improper
installaon.
The installer should have skills such as:
gas sizing
connecng gas lines, water lines, valves,
electricity,
knowledge of applicable naonal, state, and
local codes.
If you lack these skills contact a licensed professional.
Installaon Instrucons
Installaon Steps
General Instrucons
Prepare for Installaon ...................................... 5
Determine Installaon Locaon ......................... 5
Checklist to Determine Installaon Locaon ..... 8
Mount to Wall .................................................... 8
Remove the Front Panel .................................... 9
Installaon of Plumbing ..................................... 9
Checklist for Plumbing ..................................... 11
Installaon of Gas Supply ................................. 11
Connect Electricity ........................................... 13
Adjust for High Altude ................................... 13
Checklist for Gas and Electricity ....................... 13
Installaon of Temperature Controller ............ 14
Mounng the Controller .................................. 15
Final Checklist................................................... 16
Installer Qualicaons
DO NOT
Do not install the V53De indoors.
Do not install the appliance in an area where water
leakage of the unit or connecons will result in
damage to the area adjacent to the appliance or to
lower oors of the structure. When such locaons
cannot be avoided, it is recommended that a
suitable drain pan, adequately drained, be installed
under the appliance. The pan must not restrict
combuson air ow.
Do not obstruct the ow of combuson and
venlaon air. Combuson air shall not be
supplied from occupied spaces.
Do not use this appliance in an applicaon such as
a pool or spa heater that uses chemically treated
water . (This appliance is suitable for lling large or
whirlpool spa tubs with potable water.)
Do not use substute parts that are not authorized
for this appliance.
MUST DO
The installaon must conform with local codes or,
in the absence of local codes, with the Naonal
Fuel Gas Code, ANSI Z223.1/NFPA 54, or the
Natural Gas and Propane Installaon Code, CSA
B149.1. If installed in a manufactured home, the
installaon must conform with the Manufactured
Home Construcon and Safety Standard, Title 24
CFR, Part 3280 and/or CAN/SCA Z240 MH Series,
Mobile Homes.
The appliance, when installed, must be electrically
grounded in accordance with local codes or, in the
absence of local codes, with the Naonal Electrical
Code, ANSI/NFPA 70, or the Canadian Electrical
Code, CSA C22.1.
The appliance and its appliance main gas valve
must be disconnected from the gas supply piping
system during any pressure tesng of that system
at test pressures in excess of 1/2 psi (3.5 kPa)
(13.84 in W.C.).
The appliance must be isolated from the gas supply
piping system by closing its individual manual
shuto valve during any pressure tesng of the gas
supply piping system at test pressures equal to or
less than 1/2 psi (3.5 kPa) (13.84 in W.C.).
You must follow the installaon instrucons for
adequate combuson air intake and exhaust.
INFORMATION
If a water heater is installed in a closed water
supply system, such as one having a backow
preventer in the cold water supply line, means
shall be provided to control thermal expansion.
Contact the water supplier or local plumbing
inspector on how to control thermal expansion.
Type of installaon
For installaon in residenal applicaons.
Cered for installaon in manufactured (mobile)
homes.
V53De Manual 5
Prepare for installaon
Parts included
Tools needed
Materials needed
Tankless water heater
Pipe wrenches (2)
Adjustable pliers
Screwdrivers (2)
Wire cuers
Gloves
Safety glasses
Level
Tools that might be needed
Hammer drill with
concrete bits
Saw
Threading machine with
heads and oiler
Core drill with diamond
head
Torch set
Copper tubing cuer
Steel pipe cuer
Materials that may be needed
Soap soluon
Pressure relief valve
Teon tape
(recommended) or pipe
compound
Heat tape
Pipe insulaon
Electrical wire and
conduit per local code
Concrete wall anchors
Oponal pipe cover
Oponal temperature
controller
5/8” ID PVC exible
tubing
2 conductor 22 AWG
wire for controller
Single gang electrical
box
Wire nuts
Unions, drain valves,
isolaon valves
Consideraon of care for your water heater should
include evaluaon of water quality.
The water must be potable, free of corrosive
chemicals, sand, dirt, or other contaminates. It is up
to the installer to ensure the water does not contain
corrosive chemicals, or elements that can aect or
damage the heat exchanger. Water that contains
chemicals exceeding the levels below aect and
damage the heat exchanger. Replacement of the
heat exchanger due to water quality damage is not
covered by the warranty.
Determine Installaon Locaon
Water Quality
* Source: Part 143 Naonal Secondary Drinking Water
Regulaons
You must ensure that clearances will be met.
Consider the installaon environment, water quality,
and need for freeze protecon. Requirements for the
gas line, water lines, electrical connecon, and
Should overheang occur or the gas supply fail to
shut o, turn o the manual gas control valve to
the appliance.
(En cas de surchaue ou si lalimentaon en gaz ne
sarrête pas, fermez manuellement le robinet
darrêt de ladmission de gaz).
Keep the air intake locaon free of chemicals such
as chlorine or bleach that produce fumes. These
fumes can damage components and reduce the
life of your appliance.
Maximum Level
Total Hardness Up to 200 mg / L
Aluminum * Up to 0.2 mg / L
Chlorides * Up to 250 mg / L
Copper * Up to 1.0 mg / L
Dissolved Carbon Dioxide (CO2) Up to 15.0 mg / L or PPM
Iron * Up to 0.3 mg / L
Manganese * Up to 0.05 mg / L
pH * 6.5 to 8.5
TDS (Total Dissolved Solids) * Up to 500 mg / L
Zinc * Up to 5 mg / L
If you install this water heater in an area that is
known to have hard water or that causes scale build-
up the water must be treated and/or the heat
exchanger ushed regularly.
When scale build-up in the heat exchanger begins to
aect the performance of the water heater, a
diagnosc code LC#will display. Flush the heat
exchanger to prevent damage to it. Scale build up is
caused by hard water set at a high temperature.
Rinnai oers Southeastern Filtraons ScaleCuer
Water Condioning Systemthat oers superior lime
scale prevenon and corrosion control by feeding a
blend of control compounds into the cold water
supply.
Part Number Descripon
103000038
Southeastern Filtratrion
ScaleCuer System 3/4” Feed
103000039 ScaleCuer Rell
condensate disposal can be found in their respecve
installaon secons of this manual.
6 V53De Manual
Ref
Descripon
Canadian Installaons
(CSA B149.1)
US Installaons
(ANSI Z223.1 / NFPA 54)
A Clearance above grade, veranda, porch, deck, or balcony 12 inches (30 cm) 12 inches (30 cm)
B Clearance to window or door that may be opened
6 in (15 cm) for appliances ≤ 10,000 Btuh (3
kW), 12 in (30 cm) for appliances > 10,000
Btuh (3 kW) and ≤ 100,000 Btuh (30 kW), 36 in
(91 cm) for appliances >100,000 Btuh (30 kW)
4  (1.2 m) below or to side of opening;
1  (300 mm) above opening
C Clearance to permanently closed window * *
D
Vercal clearance to venlated sot, located above the terminal within a
horizontal distance of 2 feet (61 cm) from the center line of the terminal
* *
E Clearance to unvenlated sot * *
F Clearance to outside corner * *
G Clearance to inside corner * *
H
Clearance to each side of center line extended above meter/regulator
assembly
* *
I Clearance to service regulator vent outlet
Above a regulator within 3  (91 cm)
horizontally of the vercal center line of the
regulator vent outlet to a maximum vercal
distance of 15  (4.5 m)
*
J
Clearance to non-mechanical air supply inlet to building or the combuson
air inlet to any other appliance
6 in (15 cm) for appliances ≤ 10,000 Btuh (3
kW), 12 in (30 cm) for appliances > 10,000
Btuh (3 kW) and ≤ 100,000 Btuh (30 kW), 36 in
(91 cm) for appliances >100,000 Btuh (30 kW)
4  (1.2 m) below or to side of opening;
1  (300 mm) above opening
K Clearance to a mechanical air supply inlet 6  (1.83 m)
3  (91 cm) above if within 10  (3 m)
horizontally
L
Clearance above paved sidewalk or paved driveway located on public
property
7  (2.13 m) 7  (2.13 m)
M Clearance under veranda, porch, deck, or balcony
12 inches (30 cm)
*
* For clearances not specied in ANSI Z223.1/NFPA 54 or CSA B149.1, one of the following shall be indicated:
A) a minimum clearance value determined by tesng in accordance with Clause 5.21, Dra hoods; or
B) a reference to the following footnote: Clearance in accordance with local installaon codes and the requirements of the gas supplier.
A vent shall not terminate directly above a sidewalk or paved driveway that is located between two single family dwellings and serves both dwellings.
Permied only if veranda, porch, deck, or balcony is fully open on a minimum of two sides beneath the oor.
Notes: 1) In accordance with the current CSA B149.1, Natural Gas and Propane Installaon Code.
2) In accordance with the current ANSI Z223.1/NFPA 54, Naonal Fuel Gas Code.
Exhaust Outlet Clearances
AIR SUPPLY INLET
VENT TERMINAL
AREA WHERE TERMINAL
IS NOT PERMITTTED
X
V
SNOW
TERMINATION
Clearance in
Ref. A also
applies to
anticipated
snow line
V53De Manual 7
2"
12"
60"
36"
Unit clearances
Local codes supersede these clearances.
Avoid terminaon locaons near a dryer vent.
Avoid terminaon locaons near commercial
cooking exhaust.
Addional clearances
The clearance for servicing is
24 inches in front of the water
heater.
(0.30 m) to an
inside corner
(50 mm) between
terminals at same
level
(1.52 m)
vercally
between
terminals
(0.91 m) to venlated or unvenlated
sot or eve vent; or to a deck or porch
to
Combusbles
inches (mm)
to Non-
Combusbles
inches (mm)
Top of Heater
12 (305) 2 (51)
Back of Heater
0 (zero) 0 (zero)
Front (Panel)
24 (610) 0 (zero)
Front (Exhaust)
24 (610) 24 (610)
Sides of Heater
6 (152) 1/8 (3.2)
Ground/Boom
12 (305) 2 (51)
Environment
Air surrounding the water heater is used for
combuson and must be free of any compounds that
cause corrosion of internal components. These
include corrosive compounds that are found in
aerosol sprays, detergents, bleaches, cleaning
solvents, oil based paints/ varnishes, and refrigerants.
The air in beauty shops, dry cleaning stores, photo
processing labs, and storage areas for pool supplies
oen contains these compounds. Therefore it is
recommended that outdoor models be used for these
locaons where possible.
The water heater should not be installed in any areas
where the air may contain these corrosive
compounds. If it is necessary for a water heater to be
located in areas which may contain corrosive
compounds, the following instrucons are strongly
recommended.
IMPORTANT CONSIDERATIONS:
Install the water heater as far away as possible
from exhaust vent hoods.
Install as far away as possible from air inlet
vents. Corrosive fumes may be released through
these vents when air is not being brought in
through them.
Chemicals that are corrosive in nature should not
be stored or used near the water heater.
Damage and repair due to corrosive compounds in
the air is not covered by warranty.
to top
to front
to ground/boom
to side
8 V53De Manual
In addion, the solenoid valves should be connected
electrically to a surge protector with terminals. This
allows the solenoid valves to operate if the water
heater is disabled due to a diagnosc code.
The freeze protecon features will not prevent the
external piping from freezing. It is recommended that
hot and cold water pipes are insulated. Pipe cover
enclosures may be packed with insulaon for added
freeze protecon.
In the event of a power failure at temperatures below
freezing the water heater should be drained of all
water to prevent freezing damage. In addion, drain
the condensate trap and drain line.
Checklist to Determine Installaon
Locaon
The water heater is not exposed to corrosive
compounds in the air.
The water heater locaon complies with the
clearances.
The planned exhaust outlet/air intake locaon
meets the clearances.
The water supply does not contain chemicals or
exceed total hardness that will damage the heat
exchanger.
A 120 VAC, 60 Hz source is available.
The installaon must conform with local codes or,
in the absence of local codes, with the Naonal
Fuel Gas Code, ANSI Z223.1/NFPA 54, or the
Natural Gas and Propane Installaon Code, CSA
B149.1. If installed in a manufactured home, the
installaon must conform with the Manufactured
Home Construcon and Safety Standard, Title 24
CFR, Part 3280 and/or CAN/SCA Z240 MH Series,
Mobile Homes.
Leave the enre manual taped to the
temperature controller (if installed), or give the
enre manual directly to the consumer.
Mount to Wall
1. Idenfy the installaon locaon and conrm that
the installaon will meet all required clearances.
2. Securely aach the water heater to the wall using
any of the holes in the wall installaon brackets
which are at the top and boom of the water
heater. Ensure that the aachment strength is
sucient to support the weight. Refer to the
weight of the water heater in the Specicaons
secon.
Use a leveling tool to ensure that the water
heater is level. Proper operaon requires that
the water heater be level.
NOTE: The water heater should be installed in an
upright posion. Do not install upside down or on its
side.
Make sure that in case of freezing weather that the
water heater and its water lines are protected to
prevent freezing. Damage due to freezing is not cov-
ered by the warranty.
Loss of freeze protecon may result in water damage
from a burst heat exchanger or water lines.
With electrical power supplied, the water heater will
not freeze when the outside air temperature is as
cold as –4°F (-20°C) for outdoor models, when pro-
tected from direct wind exposure. Because of the
wind-chilleect, any wind or circulaon of the air
on the unit will reduce its ability to freeze protect.
The unit may be drained manually. However, it is
highly recommended that:
drain down solenoid valves are installed that will
automacally drain the unit if power is lost.
These are available in a kit, 104000059.
Freeze Protecon
V53De Manual 9
Installaon of Plumbing
A manual water control valve must be placed in the
water inlet connecon to the water heater before it is
connected to the water line. Unions may be used on
both the hot and cold water lines for future servicing
and disconnecon of the unit.
DO NOT
Do not introduce toxic chemicals such as those
used for boiler water treatment to the potable
water used for space heang.
MUST DO
The piping (including soldering materials) and
components connected to this appliance must be
approved for use in potable water systems.
Purge the water line to remove all debris and air.
Debris will damage the water heater.
If the appliance will be used as a potable water
source, it must not be connected to a system that
was previously used with a non-potable water
heang appliance.
Ensure that the water lter on the water heater is
clean and installed.
Piping Requirements
Pressure Relief Valve Requirements
Install the pressure relief valve according to local
plumbing codes and these instrucons.
An approved pressure relief valve is required by the
American Naonal Standard (ANSI Z21.10.3) for all
water heang systems, and shall be accessible for
servicing.
DO NOT
Do not plug the relief valve and do not install any
reducing ngs or other restricons in the relief
line. The relief line should allow for complete
drainage of the valve and the line.
Do not place any other type valve or shut o
device between the relief valve and the water
heater.
MUST DO
The relief valve must comply with the standard for
Relief Valves and Automac Gas Shuto Devices for
Hot Water Supply Systems ANSI Z21.22 and /or the
standard Temperature, Pressure, Temperature and
Pressure Relief Valves and Vacuum Relief Valves,
CAN1-4.4.
The relief valve must be rated up to 150 psi and to
at least the maximum BTU/hr of the appliance.
The discharge from the pressure relief valve should
be piped to the ground or into a drain system to
prevent exposure or possible burn hazards to
humans or other plant or animal life. Follow local
codes. Water discharged from the relief valve
could cause severe burns instantly, scalds, or
death.
The pressure relief valve must be manually
operated once a year to check for correct
operaon.
The relief valve should be added to the hot water
outlet line and near the hot water outlet according
to the manufacturers instrucons. DO NOT place
any other type valve or shut o device between
the relief valve and the water heater.
INFORMATION
If a relief valve discharges periodically, this may be
due to thermal expansion in a closed water supply
system. Contact the water supplier or local
plumbing inspector on how to correct this
situaon. Do not plug the relief valve.
The American Naonal Standard (ANSI Z21.10.3)
does not require a combinaon temperature and
pressure relief valve for this appliance. However,
local codes may require a combinaon
temperature and pressure relief valve.
Isolaon Valves
Rinnai strongly recommends the installaon of
isolaon valves on the cold and hot water lines
because they provide the ability to isolate the water
heater from the structures plumbing and allow quick
access to ush the heat exchanger. Flushing the heat
exchanger regularly is required as part of the proper
maintenance for this water heater.
Remove the Front Panel
Slide the plasc trim pieces on each side of the
water heater to expose the screws.
Remove the 4 screws and pull o the front panel.
10 V53De Manual
Piping Diagram for Basic Installaon
G
a
s
S
u
p
p
l
y
3
/
4
"
C
o
l
d
W
a
t
e
r
S
u
p
p
l
y
L
i
n
e
3/4" Hot Water Supply Line
Rinnai
Water Heater
Rinnai
Equipment List
Rinnai
Water Heaters
RIK-KIT (Optional)
(3/4" Fittings Include:
2 Unions, 2 Ball Valves,
2 Drain Valves and
1 Pressure Relief Valve.)
QTY
1
1
3
/
4
"
G
a
s
C
o
n
n
e
c
t
i
o
n
For Building Fixtures
Pressure Relief Valve
3/4" Ball Valve
3/4" Union
Check Valve
S
Pressure Regulator
Circulating Pump
Solenoid Valve
Boiler Drain Valve
KEY
This is not an engineered drawing. It is intended only as a guide and not
as a replacement for professionally engineered project drawings. This
drawing is not intended to describe a complete system. It is up to the
contractor/engineer to determine the necessary components and
configuration of the particular system being installed. This drawing does
not imply compliance with local building code requirements. It is the
responsibility of the contractor/engineer to ensure installation is in
accordance with all local building codes. Confer with local building
officials before installation.
V53De Manual 11
Connect Water Heater to Water Supply
Water connecons to the tankless water heater
should follow all state and local plumbing codes.
If this is a standard installaon, refer to the Piping
Diagram for Basic Installaon.
1. Plumb the cold water supply to the tankless water
heater on the 3/4” MNPT connecon at the
boom of the unit marked COLD.
2. Plumb the building hot water supply to the 3/4”
MSPT connecon marked HOT.
If a pipe cover will be installed, make sure water lines
to the water heater t.
Checklist for Plumbing
Purge the water line of all debris and air by
closing the hot isolaon valve and opening the
cold isolaon valve and its drain. Debris will
damage the water heater. Use a bucket or hose
if necessary.
Ensure that hot and cold water lines are not
crossed to the unit and are leak free.
Ensure that a pressure relief valve is installed with
a rang that exceeds the BTU input of the water
heater model. Refer to the rang plate on the
side of the water heater for BTU input.
Clean the inlet water lter by closing the cold and
hot water inlet isolaon (shut-o) valves. Put a
bucket under the lter at the boom of the water
heater to catch any water that is contained inside
the unit. Unscrew the water lter. Rinse the
lter to remove any debris. Install the lter and
open the isolaon valves.
Check for proper water pressure to the water
heater. Minimum water pressure is 20 psi. Rinnai
recommends 60-80 psi for maximum
performance.
Installaon of Gas Supply
MUST DO
A manual gas control valve must be placed in the
gas supply line to the water heater. A union can be
used on the connecon above the shut o valve
for the future servicing or disconnecon of the
unit.
Check the type of gas and the gas inlet pressure
before connecng the water heater. If the water
heater is not of the gas type that the building is
supplied with, DO NOT connect the water heater.
Contact the dealer for the proper unit to match the
gas type.
Check the gas supply pressure immediately
upstream at a locaon provided by the gas
company. Supplied gas pressure must be within
the limits shown in the Specicaons secon with
all gas appliances operang.
Before placing the appliance in operaon all joints
including the heater must be checked for gas
ghtness by means of leak detector soluon, soap
and water, or an equivalent nonammable
soluon, as applicable. (Since some leak test
soluons, including soap and water, may cause
corrosion or stress cracking, the piping shall be
rinsed with water aer tesng, unless it has been
determined that the leak test soluon is non-
corrosive.)
Use approved connectors to connect the unit to
the gas line. Purge the gas line of any debris
before connecon to the water heater.
General Instrucons
WARNING / AVERTISSEMENT
1. If you are not knowledgeable or qualied to
install gas lines or connecons, then contact a
licensed professional to install the gas supply.
2. Turn o 120v power supply.
3. Turn o the gas.
4. Gas is ammable. Do not smoke or provide other
ignion sources while working with gas.
5. Do not turn on the water heater or gas unl all
fumes are gone.
12 V53De Manual
Size the gas pipe
The gas supply must be capable of handling the enre
gas load at the locaon. Gas line sizing is based on
gas type, the pressure drop in the system, the gas
pressure supplied, and gas line type. For gas pipe
sizing in the United States, refer to the Naonal Fuel
Gas Code, NFPA 54. The below informaon is
provided as an example. The appropriate table from
the applicable code must be used.
1. For some tables, you will need to determine the
cubic feet per hour of gas required by dividing the
gas input by the heang value of the gas
(available from the local gas company). The gas
input needs to include all gas products at the
locaon and the maximum BTU usage at full load
when all gas products are in use.
2. Use the table for your gas type and pipe type to
nd the pipe size required. The pipe size must be
able to provide the required cubic feet per hour
of gas or the required BTU/hour.
Example:
The heang value of natural gas for your locaon is
1000 BTU/FT
3
. The gas input of the V53De is 120,000
BTU/HR. Addional appliances at the locaon require
65,000 BTU/hr. Therefore the cubic feet per hour =
(120,000 + 65,000) / 1000 = 185 FT
3
/HR. If the pipe
length is 20 feet then the 3/4 inch pipe size is capable
of supplying 188 FT
3
/HR of natural gas.
Gas Input of all gas products (BTU / HR)
Heang Value of Gas (BTU / FT
3
)
Cubic Feet
per Hour =
(CFH)
Any compound used on the threaded joint of the
gas piping shall be a type which resists the acon
of liqueed petroleum gas (propane / LPG).
The gas supply line shall be gas ght, sized, and so
installed as to provide a supply of gas sucient to
meet the maximum demand of the heater and all
other gas consuming appliances at the locaon
without loss of pressure.
INFORMATION
Refer to an approved pipe sizing chart if in doubt
about the size of the gas line.
Length
Pipe Size (inches)
3/4 1 1 1/4 1 1/2
10 273 514 1060 1580
20 188 353 726 1090
30 151 284 583 873
40 129 243 499 747
50 114 215 442 662
60 104 195 400 600
70 95 179 368 552
80 89 167 343 514
90 83 157 322 482
100 79 148 304 455
Pipe Sizing Table - Natural Gas
Inlet Pressure: less than 2 psi (55 inches W.C.)
Pressure Drop: 0.3 inches W.C.
Specic Gravity: 0.60
Schedule 40 Metallic Pipe
cubic feet per hour
Length
Pipe Size (inches)
1/2 3/4 1 1 1/4
10 291 608 1150 2350
20 200 418 787 1620
30 160 336 632 1300
40 137 287 541 1110
50 122 255 480 985
60 110 231 434 892
80 101 212 400 821
100 94 197 372 763
Pipe Sizing Table - Propane Gas
Inlet Pressure: 11.0 inches W.C.
Pressure Drop: 0.5 inches W.C.
Specic Gravity: 1.50
Schedule 40 Metallic Pipe
Capacity in Thousands of BTU per Hour
V53De Manual 13
Connect Electricity
Do not rely on the gas or water piping to ground the
water heater. A screw is provided in the juncon box
for the grounding connecon.
The water heater requires 120 VAC, 60 Hz power from
a properly grounded circuit.
A disconnect switch must be provided and installed
for the incoming 120 VAC power. It should be a type
that is suitable for outdoor use. Check the Naonal
Electrical Code, ANSI/NFPA 70, or the Canadian
Electrical Code, CSA C22.1, and your local codes for a
proper switch type to use in your area.
The wiring diagram is located on the Technical Sheet
aached to the inside of the front cover.
WARNING / AVERTISSEMENT
Do not use an extension cord or an adapter plug with
this appliance.
The water heater must be electrically grounded in
accordance with local codes and ordinances or, in the
absence of local codes, in accordance with the
Naonal Electrical Code, ANSI/NFPA No. 70.
Checklist for Gas and Electricity
A manual gas control valve is placed in the gas
line to the water heater.
Check the gas lines and connecons for leaks.
Conrm that the gas inlet pressure is within
limits.
Conrm that the water heater is rated for the gas
type supplied.
Conrm that the electricity is supplied from 120
VAC, 60 Hz power source and is in a properly
grounded circuit.
An extension cord or an adapter plug has not
been used with the water heater.
Adjust for High Altude
On the Dip switches, set switches No. 2 and No. 3 to
the values shown in table below for your altude.
The default seng for the appliance is 0-2000 
(0-610 m) with switches No. 2 and No. 3 in the OFF
posion.
When the Dip switch is adjusted, it is not necessary to
adjust the gas pressure seng for high altude.
Altude
Switch
No. 2
Switch
No. 3
0-2000  (0-610 m) OFF OFF
2001-5200  (610-1585 m) OFF ON
5201-7700  (1585-2347 m) ON OFF
7701-10200  (2347-3109 m) ON ON
Dip Switch
Locaon
Switch Funcons
SW1 No Funcon
SW2 High Alt.
SW3 High Alt.
SW4 Gas ON/OFF
From Disconnect
Inside the appliance
To PCB
Field
Applicaon
Factory
Connected
14 V53De Manual
Installaon of Temperature Controller
Controller Locaon
Cable Lengths and Sizes
The controller should be out of reach of small
children.
Avoid locaons where the controller may become
hot (near the oven or radiant heater).
Avoid locaons in direct sunlight. The digital
display may be dicult to read in direct sunlight.
Avoid locaons where the temperature controller
could be splashed with liquids.
Do not install in locaons where it can be
adjusted by the public.
The cable for the temperature controller should be a
non-polarized two-core cable with a minimum gauge
of 22 AWG. The maximum cable length from each
controller to the water heater depends on the total
number of wired controllers connected to the water
heater.
Number of Wired
Controllers
Maximum Cable Length for each
Controller to Water Heater
1 328  (100 m)
2 164  (50 m)
3 or 4 65  (20 m)
Turn the power o. Do not aempt to connect the
temperature controllers with the power on. Although
the controller is a low voltage device, there is 120 volt
potenal next to the temperature controller
connecons inside the unit.
Do not connect the temperature controller to the
120VAC terminals provided for the oponal solenoid
drain valves.
WARNING / AVERTISSEMENT
Conguraons
A maximum of 4 temperature controllers can be
installed for a water heater or bank of water heaters.
This includes the controller built into an indoor water
heater. Controllers can only be wired in parallel.
Controllers cannot be wired in series.
If 4 MC-601-US controllers are installed,
simultaneously press the Priority and ON/OFF buons
on the fourth controller unl a beep sounds.
Residenal Applicaons: MC-601-US-BK,
MC-601-US-W
Wire controllers in parallel
V53De Manual 15
Mounng the Controller
Follow the procedure below to install an MC-601-US
temperature controller.
1. Determine a suitable locaon for the controller.
2. Make three holes in the wall as shown.
3. Run the wiring between the controller and the
Rinnai water heater or the controller and another
controller as shown in the illustraon on P.14.
4. Remove the face plate from temperature
controller using a screwdriver.
5. Connect the cable to the temperature controller
(refer to remote controller installaon instrucons
for details).
6. Mount the controller to the wall using the holes
drilled in step 2.
7. Disconnect power from the water heater.
8. Remove the screw on the Quick Cable Connector.
(Fig. 1)
9. Rotate the Quick Cable Connector. (Fig. 2)
10. Route the wires through the Cable Access Hole
(Fig. 2)
11. Loosen the clamp screw and secure the wires with
the clamp. The clamp is in the box with the
temperature controller. Make sure the wire
lengths are of sucient length. There should be
no tension in the wires. (Fig. 3)
12. Loosen 2 screws on the terminals for controls and
connect the cable (polarity is unimportant, either
color can be connected to either terminal). When
connecng more than 2 cables, connect them in
parallel. (Fig. 4)
13. Reinstall the Quick Cable Connecon. (Fig. 5)
Outline of Remote
securing screw
1-21/32"
3-5/16"
securing screw
wiring hole
16 V53De Manual
Final Checklist
The water heater is not subject to corrosive
compounds in the air.
The water supply does not contain chemicals or
exceeds total hardness that will damage the heat
exchanger.
Clearances from the water heater unit are met.
Clearances from the exhaust outlet / air intake
are met.
Purge the water line of all debris and air by
closing the hot isolaon valve and opening the
cold isolaon valve and its drain. Debris will
damage the water heater. Use a bucket or hose
if necessary.
Ensure that hot and cold water lines are not
crossed to the unit and are leak free.
Clean the inlet water lter by closing the cold and
hot water inlet isolaon (shut-o) valves. Put a
bucket under the lter at the boom of the water
heater to catch any water that is contained inside
the unit. Unscrew the water lter. Rinse the
lter to remove any debris. Install the lter and
open the isolaon valves.
Ensure that a pressure relief valve is installed with
a rang that exceeds the BTU input of the water
heater model. Refer to the rang plate on the
side of the water heater for BTU input.
A manual gas control valve has been placed in the
gas line to the water heater.
Check the gas lines and connecons for leaks.
Conrm that the gas inlet pressure is within
limits.
Conrm that the water heater is rated for the gas
type supplied.
Conrm that the electricity is supplied from a 120
VAC, 60 Hz power source, is in a properly
grounded circuit, and turned on.
Verify the temperature controller is funconing
properly.
Verify that Dip switches No. 2 and No. 3 are set
correctly for your altude.
Verify the system is funconing correctly by
connecng your manometer to the gas pressure
test port on the water heater. Operate all gas
appliances in the home or facility at high re. The
inlet gas pressure at the water heater must not
drop below that listed on the rang plate.
If the water heater is not needed for immediate
use, then drain the water from the heat
exchanger.
Install the front panel.
Explain to the customer the importance of not
blocking the exhaust outlet or air intake.
Explain to the customer the operaon of the
water heater, safety guidelines, maintenance, and
warranty.
The installaon must conform with local codes or,
in the absence of local codes, with the Naonal
Fuel Gas Code, ANSI Z223.1/NFPA 54, or the
Natural Gas and Propane Installaon Code, CSA
B149.1. If installed in a manufactured home, the
installaon must conform with the Manufactured
Home Construcon and Safety Standard, Title 24
CFR, Part 3280 and/or CAN/SCA Z240 MH Series,
Mobile Homes.
Leave the enre manual taped to the
temperature controller (if installed), or give the
enre manual directly to the consumer.
V53De Manual 17
Technical Data
Specicaons
* Minimum ow may vary slightly depending on the temperature seng and the inlet water temperature.
Minimum acvaon ow is 0.6 GPM (1.5 L/min).
Our products are connually being updated and improved; therefore, specicaons are subject to change without prior noce.
The maximum inlet gas pressure must not exceed the value specied by the manufacturer. The minimum value listed is for the purpose of input
adjustment.
V53De
Minimum Gas Consumpon Btu/h 15,500 (LP & NG Both)
Maximum Gas Consumpon Btu/h 120,000
Hot water capacity (Min - Max) * 0.4 - 5.3 GPM (1.5 - 20.0 L/min)
Temperature Sengs (without temperature controller) 120° F (49° C), default or 140° F (60° C)
Temperature Controller Default Seng 115° F (46° C)
Maximum Temp Seng (residenal)
see Temperature Ranges for more informaon
140° F (60° C)
Minimum Temperature Seng 115° F (46° C)
Weight 29.7 lb. (13.5 kg)
Noise level 54 dB
Electrical Consumpon
Normal 50W
Standby 2 W
An-frost Protecon 64W
Max Current 1.2A
Fuse 5A
By-Pass Control Fixed
Gas Supply Pressure
Natural Gas 4.5 - 10.5 inch W.C.
Propane 8.0 - 13.5 inch W.C.
Type of Appliance Temperature controlled connuous ow gas hot water system.
Connecons
Gas Supply: 3/4" MNPT, Cold Water Inlet: 3/4" MNPT, Hot Water Outlet: 3/4"
MNPT
Ignion System Direct Electronic Ignion
Electric Connecons Appliance: AC 120 Volts, 60Hz. Remote Control: DC 12 Volts (Digital)
Water Temperature Control Simulaon Feedforward and Feedback.
Water Supply Pressure
Minimum Water Pressure: 20 PSI (Recommended 30-80 PSI for maximum
performance)
Maximum Water Supply Pressure 150 PSI
Remote Control Cable Non-Polarized Two Core Cable (Minimum 22 AWG)
Cered for installaon in manufactured (mobile) homes Yes
NOx
Complies with South Coast Air Quality Management District 40 ng/J
NOx emission levels
18 V53De Manual
Dimensions
DIM DESCRIPTION V53De
in (mm)
A Width 14.0 (356)
B Depth * 7.9 (202)
C Height - Unit 19.8 (503)
D
Height - with
brackets
22.5 (571)
E
Hot Water Outlet -
from wall *
3.4 (87)
F
Hot Water Outlet -
from center
4.1 (105)
G
Cold Water Inlet -
from wall *
2.7 (68)
H
Cold Water Inlet -
from center
0.4 (10)
I
Gas Connecon -
from wall *
3.0 (77)
J
Gas Connecon -
from center
3.3 (83)
K
From base to gas
connecon
1.6 (40)
From base to cold
connecon
2.0 (50)
From base to hot
connecon
1.5 (39)
G
K
H
A
C
D
I
F
J
B
E
V53De Manual 19
Pressure Drop Curve
Water Flow Curve
0.0
1.0
2.0
3.0
4.0
5.0
6.0
0 25 50 75 100 125 150
delta T - Temperature Rise (°F)
Pressure Loss ( head)
Water Flow (gpm)
Water Flow (gpm)
Pressure Loss (psi)
20 V53De Manual
Ladder Diagram
V53De Manual 21
Important Facts about your Water Heater
Thank you for purchasing a Rinnai Tankless Water Heater. For proper operaon and safety, it is
important to follow the instrucons and adhere to the safety precauons.
Read all of the instrucons and the warranty thoroughly before operang this water heater. Keep this
manual in a safe place.
NOTICE: Rinnai somemes shares customer contact informaon with businesses that we believe provide
products or services that may be useful to you. By providing this informaon, you agree that we can
share your contact informaon for this purpose. If you prefer not to have your informaon shared with
these businesses, please contact customer service and ask not to have your informaon shared. We
will however, connue to contact you with informaon relevant to the product(s) you registered and/or
you account with us.
Do not store or use gasoline or other ammable vapors and liquids in the vicinity of this or any
other appliance.
WHAT TO DO IF YOU SMELL GAS
Leave the premises.
Do not try to light any appliance.
Do not touch any electrical switch; do not use any phone in your building.
Immediately call your gas supplier from a neighbors phone. Follow the gas suppliers
instrucons.
If you cannot reach your gas supplier, call the re department.
Installaon and service must be performed by a licensed professional.
If the informaon in these instrucons is not followed exactly, a re or
explosion may result causing property damage, personal injury or death.
WARNING
FOR OUTDOOR APPLICATIONS ONLY
V53De ................... REU-AM1620WD-US
Outdoor Tankless Water Heater
Operaon Instrucons
Assurez-vous de bien suivre les instrucons données dans cee
noce pour réduire au minimum le risque dincendie ou
dexplosion ou pour éviter tout dommage matériel, toute blessure ou la mort.
AVERTISSEMENT
22 V53De Manual
Consumer Operaon Guidelines for the Safe Operaon of your Water Heater
FOR YOUR SAFETY READ BEFORE OPERATING
A. This appliance does not have a pilot. It is
equipped with an ignion device which
automacally lights the burner. Do not try to light
the burner by hand.
B. BEFORE OPERATING ,smell all around the
appliance area for gas. Be sure to smell next to
the oor because some gas is heavier than air and
will sele on the oor.
WHAT TO DO IF YOU SMELL GAS:
Do not try to light any appliance.
Do not touch any electric switch; do not use any
phone in your building.
Immediately call your gas supplier from a
neighbors phone. Follow the gas suppliers
instrucons.
If you cannot reach your gas supplier, call the re
department.
C. Use only your hand to push in or turn the gas
control knob. Never use tools. If the knob will not
push in or turn by hand, do not try to repair it, call
a qualied licensed professional. Force or
aempted repair may result in a re or explosion.
D. Do not use this appliance if any part has been
under water. Immediately call a qualied licensed
professional to inspect the appliance and to
replace any part of the control system and any gas
control which has been under water.
(Nulisez pas cet appareil sil a été plongé dans
leau, même parellement. Faites inspecter
lappareil par un technicien qualié et remplacez
toute pare du système de contrôle et toute
commande qui ont été plongés dans leau).
TO TURN OFF GAS TO APPLIANCE
1. Turn o all electric power to the appliance using
the ON/OFF buon.
2. Set the thermostat to lowest seng.
3. Turn the gas valve clockwise to the full OFF
posion.
OPERATING INSTRUCTIONS
If you do not follow these instrucons exactly, a re or explosion may
result causing property damage, personal injury or loss of life.
WARNING
CLOSE
Manual Valve
OPEN
1. STOP! Read the safety informaon above.
2. Set the thermostat to lowest seng.
3. Turn o electric power to the appliance using the
ON/OFF buon.
4. This appliance is equipped with an ignion device
which automacally lights the burner. Do not try
to light the burner by hand.
5. Turn the gas valve clockwise to the full OFF
posion.
6. Wait ve (5) minutes to clear out any gas. Then
smell for gas, including near the oor. If you smell
gas, STOP! Follow Bin the safety informaon
above. If you dont smell gas, go to the next step.
7. Turn the gas valve counterclockwise to the full ON
posion.
8. Turn on electric power to the appliance using the
ON/OFF buon.
9. Set the thermostat to desired seng.
10. Open a hot water tap. If the appliance will not
operate, follow the instrucons To Turn O Gas
To Applianceand call your licensed professional
or gas supplier. See manual for addional
informaon.
AVERTISSEMENT
V53De Manual 23
How to Use the Temperature Controller
The V53De does not come with a temperature
controller. There are several models of temperature
controllers that can be purchased separately.
A maintenance display or status monitor is
provided in the front panel to indicate operang
status and error codes.
The MC-601-US controller is the standard
temperature controller.
DO NOT repeatedly operate the water heater and
then use a hot water tap while the controller is
turned o. Operang the water heater in this way to
alternately produce hot water may cause water to
condense on the outside of internal parts and
accumulate in the water heater cabinet.
Dimensions (inches): 3.54 W x 4.72 H x 0.70 D
90mm x 120mm x 17.7mm
Before operang, smell all around the appliance
area for gas. Be sure to smell next to the oor
because some gas is heavier than air and will sele
on the oor.
Keep the area around the appliance clear and free
from combusble materials, gasoline, and other
ammable vapors and liquids.
Always check the water temperature before
entering a shower or bath.
Do not use this appliance if any part has been under
water. Immediately call a licensed professional to
inspect the appliance and to replace any part of the
control system and any gas control which has been
under water.
(Nulisez pas cet appareil sil a été plongé dans
leau, même parellement. Faites inspecter
lappareil par un technicien qualié et remplacez
toute pare du système de contrôle et toute
commande qui ont été plongés dans leau).
Should overheang occur or gas supply fail to shut
o, turn o the manual gas control valve to the
appliance.
Do not adjust the Dip Switch unless specically
instructed to do so.
Do not use an extension cord or an adapter plug
with this appliance.
Any alteraon to the appliance or its controls can
be dangerous and will void the warranty.
If you install this water heater in an area that is
known to have hard water or that causes scale
build-up the water must be treated and/or the heat
exchanger ushed regularly. Rinnai provides a
Scale Control Systemthat oers superior lime
scale prevenon and corrosion control by feeding a
blend of control compounds into the water supply.
Damage and repair due to corrosive compounds in
the air is not covered by warranty.
Keep the air intake locaon free of chemicals such
as chlorine or bleach that produce fumes. These
fumes can damage components and reduce the life
of your appliance. Damage and repair due to scale
in the heat exchanger is not covered by warranty.
WARNING / AVERTISSEMENT
Temperature
Selecon
Priority
Buon
ON/OFF
Buon
In Use
Indicator
Temperature
Display
42
24 V53De Manual
How to Set the Temperature
While any hot water is being provided,
the temperature seng cannot be set
any lower than 115° F.
NOTICE
Check local codes for the maximum water
temperature seng allowed when used
in nursing homes, schools, day care
centers, and all other public applicaons.
NOTICE
If a newly installed unit with a controller
has not been powered for at least 6 hours
then the temperature will return to the
default seng of 115° F (46°C) if power is
interrupted.
NOTICE
There may be a variaon between the
temperature displayed on the
temperature controller and the
temperature at the tap due to weather
condions or the length of pipe to the
water heater.
NOTICE
1. If the water heater is o, press
the Power buon to turn on.
2. If the Priority light is o, then
press the Priority buonon the
temperature controller. The
green Priority light will glow
indicang that this controller is
controlling the temperature and
that the water heater is ready to
supply hot water. (The priority
can only be changed while no hot
water is running.)
3. Press the up or down buons to
obtain the desired temperature
seng.
All hot water sources are able to
provide water at this temperature
seng unl it is changed again at
this or another temperature
controller.
DANGER
Hot water can be dangerous, especially for infants or children, the elderly,
or inrm. There is hot water scald potenal if the thermostat is set too high.
Water temperatures over 125° F (52° C) can cause severe burns or scalding
resulng in death.
Hot water can cause rst degree burns with exposure for as lile as:
3 seconds at 140° F (60° C)
20 seconds at 130° F (54° C)
8 minutes at 120° F (49° C)
Test the temperature of the water before placing a child in the bath or
shower.
Do not leave a child or an inrm person in the bath unsupervised.
This water heater requires a minimum ow rate to operate. This rate can be found on the specicaon page in
this manual. In some cases when you are not geng hot water or if the water alternates between hot and cold,
it is due to the water ow being below or close to the minimum ow rate. Increasing the ow rate should
resolve these problems in these cases.
If you are experiencing issues with higher temperature sengs, then reduce the temperature seng. Selecng a
temperature closer to that which is actually used at the faucet will increase the amount of hot water being
delivered to the faucet, due to less cold water mixing at the xture.
HOT / CHAUD
BURN
V53De Manual 25
Temperatures Available with a Controller
The water heater can deliver water at only one temperature seng at a me. The available temperatures are
provided below. A temperature lower than 115° F (46° C) can be obtained at the tap by mixing with cold water.
To change the temperature scale from Celsius to Fahrenheit or vice versa, press and hold the ON/OFF buon for
5 seconds while the water heater is OFF.
Seng Controller to Mute
On the MC-601-US to eliminate the beeps when keys are pressed or to turn the beeps back on, press and hold
both the up and down buons unl a beep is heard (approximately 5 seconds).
Locking the Controller
The MC-601-US controller can be locked by pressing the Priority buon and the up buon together for 5
seconds. A beep will sound conrming that the controller is locked. The display will alternately show LOC”, the
temperature seng, and a diagnosc code if one has been acvated. All of the controllers in the system are
also locked.
To unlock the controller press the Priority buon and the up buon together for 5 seconds.
Temperature Sengs Available (°F)
V53De 115 120 125 130 135 140
Temp in Celsius °C 46 49 52 54 57 60
Water temperatures over 125°F (52°C) can cause severe burns or scalding. Refer to the Danger Alert on water
temperatures. Rinnai shall not, in any event, be liable for damages resulng from such misuse or misapplicaon.
These temperatures are suggesons only:
DO NOT adjust the other switches unless specically
instructed to do so.
WARNING / AVERTISSEMENT
Kitchen 120 °F (49° C)
Shower 98 - 110 °F (37 - 43 °C)
26 V53De Manual
Temperature Opons Without a Temperature Controller
The default temperature seng for this appliance installed without a temperature controller is 120° F (49° C).
If desired, the temperature seng can be changed to 140° F (60° C), as well as other temperature increments
by push buon adjustments, as described below.
1
2
3
4
5
PCB Interface Layout and Funcons
1. Push Buon 1 (PB1) - White
Data transfer buon for PCB replacement.
2. Push Buon 2 (PB2) - Black
MODE buon - places PCB in programming mode.
3. Push Buon 3 (PB3) - White
MENU buon - cycles through available menus 1, 2, 3, 4, 5 and 6
(see table below).
4. Push Buon 4 (PB4) - White
VALUE buon - cycles through available menu values
(see table below).
5. Push Buon 5 (PB5) - White
Forced High/Low selecon rate seng
6. LED Digital Display
Displays MENU (1, 2, etc.), VALUE (A, B, etc.) and Forced Low/High status
(L or H).
Dip Switch detail when
viewed from the front
Menu #
Menu
Descripon
Value
A b C b
1 Gas Type LPG NG
2 Model Type 1620
3 Fixed Temperatures
120°F
48.9°C
140°F
60°C
4 Max Temperature Seng of Controller(s)
120°F
48.9°C
140°F
60°C
5 OFF Water Flow Rate
+5°F
+3°C
+11°F
+6°C
6 Adjustment due to piping heat loss
+0°F
+0°C
+2°F
+1°C
+4°F
+2°C
+5°F
+3°C
6
Programming Parameters
V53De Manual 27
Code Denion Remedy
02
No burner operaon during freeze
protecon mode
Service Call
10 Air Supply or Exhaust Blockage
Check that nothing is blocking the inlet or exhaust.
licensed
professional
only
Verify dip switches and programming parameters are set properly.
Check fan for blockage.
11
No Ignion
(heater not turning on)
Check that the gas is turned on at the water heater, gas meter, or cylinder.
If the system is propane, make sure that gas is in the tank.
Ensure appliance is properly grounded.
licensed
professional
only
Ensure gas type and pressure is correct.
Ensure gas line, meter, and/or regulator is sized properly.
Bleed all air from gas lines.
Verify dip switches and programming parameters are set properly.
Ensure igniter is operaonal.
Check igniter wiring harness for damage.
Check gas solenoid valves for open or short circuits.
Remove burner cover and ensure all burners are properly seated.
Remove burner plate and inspect burner surface for condensaon or debris.
Check the ground wire for the PC board.
12 No Flame
Check that the gas is turned on at the water heater, gas meter, or cylinder.
Check for obstrucons in the ue outlet.
If the system is propane, make sure that gas is in the tank.
licensed
professional
only
Ensure gas line, meter, and/or regulator is sized properly.
Ensure gas type and pressure is correct.
Bleed all air from gas lines.
Ensure condensaon collar was installed properly.
Verify dip switches and programming parameters are set properly.
Check power supply for loose connecons.
Check power supply for proper voltage and voltage drops.
Ensure ame rod wire is connected.
Check ame rod for carbon build-up.
Disconnect and reconnect all wiring harnesses on unit and PC board.
Check for DC shorts at components.
Check gas solenoid valves for open or short circuits.
Remove burner plate and inspect burner surface for condensaon or debris.
Diagnosc Codes
Some of the checks below may need to be done by a licensed professional.
Call a licensed professional for any remedy that involves gas or electricity.
Call a licensed professional if you have any doubt or reservaon about
performing the remedy yourself.
WARNING
This water heater is designed to display diagnosc codes. If there is a potenal operaon concern refer to the
code and remedy on the next page.
Front Panel Display Indicaons
- - Standby (power is supplied but there is no demand for hot water).
On Hot water is being supplied.
FL or FH Stands for Forced Low and Forced High combuson. Only seen during the gas pressure
seng procedure which is done when certain components are replaced.
Error code ashing The error code will stop ashing aer the problem is corrected and the water heater
supplies hot water.
AVERTISSEMENT
28 V53De Manual
Code Denion Remedy
14
Thermal Fuse has
acvated
Check for restricons in air ow around unit and exhaust outlet.
licensed
professional
only
Check gas type of unit and ensure it matches gas type being used.
Check for low water ow in a circulang system causing short-cycling.
Ensure dip switches and programming parameters are set to the proper posion.
Check for foreign materials in combuson chamber and/or exhaust piping.
Check heat exchanger for cracks and/or separaons.
Check heat exchanger surface for hot spots which indicate blockage due to scale
build-up. Refer to instrucons in manual for ushing heat exchanger. Hard water
must be treated to prevent scale build up or damage to the heat exchanger.
Measure resistance of safety circuit.
Ensure high re and low re manifold pressure is correct.
Check for improper conversion of product.
16
Over Temperature
Warning (safety
shutdown because unit is
too hot)
Check for restricons in air ow around unit and exhaust outlet.
licensed
professional
only
Check for low water ow in a circulang system causing short-cycling.
Check for foreign materials in combuson chamber and/or exhaust piping.
Check for blockage in the heat exchanger.
19 Electrical Grounding
Check all components for electrical short.
32
Outgoing Water
Temperature Sensor
Check sensor wiring for damage.
Measure resistance of sensor.
Clean sensor of scale build-up.
Replace sensor.
33
Heat Exchanger Outgoing
Temperature Sensor
41
Outside temperature
thermistor
Check sensor wiring for damage.
Measure resistance of sensor.
Clean sensor of scale build-up.
Replace sensor.
52
Modulang Solenoid Valve
Signal
Check modulang gas solenoid valve wiring harness for loose or damaged terminals.
Measure resistance of valve coil.
61 Combuson Fan
Ensure fan will turn freely.
Check wiring harness to motor for damaged and/or loose connecons.
Measure resistance of motor winding.
70 PC Board Replace the PC Board.
71 Solenoid Valve Circuit Replace the PC Board.
72 Flame Sensing Device
Verify ame rod is touching ame when unit res.
Check all wiring to ame rod.
Remove ame rod and check for carbon build-up; clean with sand paper.
Check inside burner chamber for any foreign material blocking ame at ame rod.
Measure micro amp output of sensor circuit with ame present.
Replace ame rod.
LC#
LC0,
LC1...
Scale Build-up in Heat
Exchanger (when checking
maintenance code history,
“00” is substuted for
LC”)
LC0~LC9 indicates that there is scale build up in the heat exchanger and that the heat
exchanger needs to be ushed to prevent damage. Refer to ushing instrucons in manual.
Hard water must be treated to prevent scale build up or damage to the heat exchanger.
To operate the water heater temporarily unl the heat exchanger can be ushed, push the On/
O buon on the temperature controller 5 mes. Repeated LC codes will eventually lockout
the water heater.
Please call Rinnai technical department.
FF
Maintenance Indicator
Placeholder in Diagnosc code history indicang that a service provider performed
maintenance or service.
Enter this code aer performing service by pressing (Up) , (Down) and ON/OFF
consecuvely. FF is visible on the monitor.
No
code
Nothing happens when
water ow is acvated.
Clean inlet water supply lter.
On new installaons ensure hot and cold water lines are not reversed.
Verify you have at least the minimum ow rate required to re unit.
licensed
professional
only
Check for cold to hot cross over. Isolate circulang system if present. Turn o cold water to the
unit, open pressure relief valve; if water connues to ow, there is bleed over in your plumbing.
Verify turbine spins freely.
Measure the resistance of the water ow control sensor.
If the display is blank and clicking is coming from the unit, disconnect the water ow servo
motor. If the display comes on then replace the water ow servo motor.
* See Electrical Diagnoscson Technical Data Sheet located inside the front cover of water heater.
V53De Manual 29
The appliance must be inspected annually by a
licensed professional. Repairs and maintenance
should be performed by a licensed professional. The
licensed professional must verify proper operaon
aer servicing.
Cleaning
It is imperave that control compartments, burners,
and circulang air passageways of the appliance be
kept clean.
Clean as follows:
1. Turn o and disconnect electrical power. Allow to
cool.
2. Close the water shut o valves. Remove and clean
the water inlet lter.
3. Remove the front panel by removing 4 screws.
4. Use pressurized air to remove dust from the main
burner, heat exchanger, and fan blades. Do not
use a wet cloth or spray cleaners on the burner.
Do not use volale substances such as benzene
and thinners. They may ignite or fade the paint.
5. Use so dry cloth to wipe cabinet.
Air Inlet / Exhaust Outlet
The air inlet and exhaust outlet should be inspected
at least annually for blockages or damage. If it is
blocked contact a licensed professional.
Motors
Motors are permanently lubricated and do not need
periodic lubricaon. However you must keep fan and
motor free of dust and dirt by cleaning annually.
Temperature Controller
Use a so damp cloth to clean the temperature
controller. Do not use solvents.
Lime / Scale Build-up and Water Quality
If you receive diagnosc code LC#(LC1, LC2,…),
refer to the procedure, Flushing the Heat Exchanger.
Refer to the secon on Water Quality to see if your
water needs to be treated or condioned. (When
checking maintenance code history, “00” is
substuted for LC#”.)
The water must be potable, free of corrosive
chemicals, sand, dirt, or other contaminates. It is up
to the installer to ensure the water does not contain
corrosive chemicals, or elements that can aect or
damage the heat exchanger. Water that contains
chemicals exceeding the levels below aect and
damage the heat exchanger. Replacement of the
heat exchanger due to water quality damage is not
covered by the warranty.
Snow Accumulaon
Keep the area around ue terminal free of snow and
ice. The appliance will not funcon properly if the
intake air or exhaust is impeded (blocked or parally
blocked) by obstrucons.
Coastal Installaons
Installaons located in or near coastal areas may
require addional maintenance due to corrosive
airborne ocean salt.
Required Maintenance
To protect yourself from harm, before performing maintenance:
Turn o the electrical power supply by unplugging the power cord or by turning o the electricity at the
circuit breaker. (The temperature controller does not control the electrical power.)
Turn o the gas at the manual gas valve, usually located immediately below the water heater.
Turn o the incoming water supply. This can be done at the isolaon valve immediately below the water
heater or by turning o the water supply to the building.
WARNING / AVERTISSEMENT
Keep the appliance area clear and free from combusble
materials, gasoline, and other ammable vapors and liquids.
WARNING / AVERTISSEMENT
The appliance must be inspected annually by a licensed professional. Repairs and maintenance should be
performed by a licensed professional. The licensed professional must verify proper operaon aer servicing.
The following maintenance items are required for the proper operaon of your water heater.
30 V53De Manual
Clean the water lter
Clean the inlet water lter by closing the cold and hot
water inlet isolaon (shut-o) valves. Put a bucket
under the lter at the boom of the water heater to
catch any water that is contained inside the unit.
Unscrew the water lter. Rinse the lter to remove
any debris. Install the lter and open the isolaon
valves.
Pressure Relief Valve:
Operate the valve manually once a year. In doing so,
it will be necessary to take precauons with regard to
the discharge of potenally scalding hot water under
pressure. Ensure discharge has a place to ow.
Contact with your body or other property may cause
damage or harm.
Visual Inspecon of Flame
Verify proper operaon aer servicing. The burner
must ame evenly over the enre surface when
operang correctly. The ame must burn with a clear,
blue, stable ame. See the parts breakdown of the
burner for the locaon of the view ports. The ame
paern should be as shown in the gures below.
Freeze Protecon
Make sure that in case of freezing weather that the
water heater and its water lines are adequately
protected to prevent freezing. Damage due to
freezing is not covered by the warranty. Refer to the
secon on Freeze Protecon.
Drain down solenoid valves be purchased and
installed that will automacally drain the unit if
power is lost. These are available in a kit,
104000059. (The condensate trap is not aected
by the auto drain down solenoid valves and will
have to be manually drained.)
Winterizing
These recommendaons are intended to suggest
pracces which are eecve for winterizing the water
heater. They should be used as a guide only. No
liability is assumed for any issues resulng from the
use of this informaon.
GAS
Shut o the gas to the water heater. It is generally
preferable to shut o the gas service to the enre
locaon if gas is not going to be used.
WATER
Shut o the cold water supply to the water heater. It
is generally preferable to shut o the water to the
enre locaon if water is not going to be used.
Drain the water heater by opening the drain valves on
the cold water line and hot water line.
Open several hot water taps and remove the lter
assembly at the water inlet in order to allow room for
expansion in case there is water in the lines that
freeze.
ELECTRIC
Disconnect the power supply by either unplugging the
electrical cord or by turning o the circuit breaker to
the water heater to prevent potenal damage from
irregular power surges or interrupons.
AIR INLET AND EXHAUST
Place a cover over the front panel (air inlet and
exhaust). The cover should be easy to apply and
remove. This will prevent debris, leaves, and small
animals from entering the water heater which could
cause air ow issues upon return to service.
Tesng the pressure relief valve should only be
performed by a licensed professional. Water
discharged from the pressure relief valve could cause
severe burns instantly or death from scalds.
WARNING / AVERTISSEMENT
V53De Manual 31
Water Heater
Pressure Relief Valve
3/4" Ball Valve
3/4" Union
Check Valve
S
Pressure Regulator
Circulating Pump
Solenoid Valve
Boiler Drain Valve
KEY
G
a
s
S
u
p
p
l
y
V1
V3
V2
V4
H1
H2
H3
Circulating Pump
C
o
l
d
W
a
t
e
r
L
i
n
e
H
o
t
W
a
t
e
r
L
i
n
e
n
-
l
i
n
e
F
i
l
t
e
r
I
Rinnai
An LC or “00” diagnosc code indicates the unit is beginning to lime up and must be ushed. Failure to ush the
appliance will cause damage to the heat exchanger. Damage caused by lime build-up is not covered by the
units warranty.
Flushing the heat exchanger
1. Disconnect electrical power to the water heater.
2. Close the shuto valves on both the hot water and
cold water lines (V3 and V4).
3. Connect pump outlet hose (H1) to the cold water
line at service valve (V2).
4. Connect drain hose (H3) to service valve (V1).
5. Pour 4 gallons of undiluted virgin, food grade, white
vinegar into pail.
6. Place the drain hose (H3) and the hose (H2) to the
pump inlet into the cleaning soluon.
7. Open both service valves (V1 and V2) on the hot
water and cold water lines.
8. Operate the pump and allow the vinegar to circulate
through the water heater for at least 1 hour at a rate
of 4 gallons per minute (15.1 liters per minute).
9. Turn o the pump.
10. Rinse the vinegar from the water heater as follows:
a. Remove the free end of the drain hose (H3) from
the pail. Place in sink or outside to drain.
b. Close service valve, (V2), and open shuto valve,
(V4). Do not open shuto valve, (V3).
c. Allow water to ow through the water heater for
5 minutes.
d. Close shuto valve (V4). When unit has nished
draining remove the in-line lter at the cold water
inlet and clean out any residue. Place lter back
into unit and open valve (V4).
e. Close service valve, (V1), and open shuto valve,
(V3).
11. Disconnect all hoses.
12. Restore electrical power to the
water heater.
32 V53De Manual
To manually drain the water:
1. Shut o cold water supply and gas supply.
2. Turn o the temperature controller.
3. Disconnect the power to the water heater.
4. Place a container to catch the water. Remove the drain caps on
both isolaon valves and open both valves above the caps (blue
and red valve handles). -OR- remove hot water drain plug.
5. Remove water lter to drain the cold water.
If the water heater is not going to be used during a period of possible freezing weather, it is recommended that
the water inside the water heater be drained.
To avoid burns, wait unl the equipment cools down
before draining the water. The water in the appliance
will remain hot aer it is turned o.
Manual Draining of the Water Heater
To resume normal operaon:
1. Conrm that the gas supply is turned o, and that all taps are
closed.
2. Screw in the water lter in the cold water inlet.
3. Replace the drain caps and close both isolaon valves. -OR- install
hot water drain plug.
4. Open the cold water supply.
5. Open a tap and conrm that water ows, and then close.
6. Turn on the power.
7. Aer conrming that the temperature controller is o, turn on the
gas supply.
8. Turn on the temperature controller.
Running a low volume of water through the water heater to prevent freezing
If the temperature exceeds the ability of the water heater to freeze protect
itself, or if power is lost, the following steps may prevent the water heater
and external piping from freezing. (Units connected with EZConnect® Cable
(2 unit link) should be drained to prevent freezing if not in use.)
1. Turn the water heater o.
2. Close the gas supply valve.
3. Turn on a hot water tap to ow water about 0.1 gal/min or where the
stream is about 0.2 inches thick.
When the water heater or external piping has frozen
1. Do not operate the water heater if it or the external piping is frozen.
2. Close the gas and water valves and turn o the power.
3. Wait unl the water thaws. Check by opening the water supply valve.
4. Check the water heater and the piping for leaks.
HOT
COLD
ON!
0.1 gal/min or
about 0.2 inch
thick
WARNING / AVERTISSEMENT
Water
lter
Hot water
outlet
Cold water
inlet
* Use a wrench or other
tool to unscrew the hot
water drain plug.
Hot water
drain plug
V53De Manual 33
Limited Warranty
What is Covered?
The Rinnai Standard Limited Warranty covers any defects in materials or workmanship when the product is
installed and operated according to Rinnai wrien installaon instrucons, subject to the terms within this
Limited Warranty document. This Limited Warranty applies only to products that are installed correctly in the
United States and Canada. Improper installaon may void this Limited Warranty. It is recommended that a
trained and qualied professional who has aended a Rinnai installaon training class complete your
installaon. This Limited Warranty coverage, as set out in the table below, extends to the original purchaser and
subsequent owners, but only while the product remains at the site of the original installaon, and terminates if
the product is moved or reinstalled at a new locaon.
Item
Period of Coverage (from date of purchase)
Residenal
Applicaons
If installed with a tankless
isolaon valve kit for
residenal applicaons
If used for both residenal
water heang and space
heang purposes
Heat Exchanger 10 years
[1]
12 years
[1]
10 years
[2]
All Other Parts and
Components
5 years
[1]
5 years
[1]
5 years
[2]
Reasonable Labor 1 year 1 year 1 year
[1] The warranty period is reduced to 3 years from date of purchase when the water heater is used as a circulang water heater
within a hot water circulaon loop, where the water heater is in series with a circulaon system and all circulang water ows
through the water heater, and where an on-demand recirculaon system is not incorporated.
On-demand recirculaon is dened as a hot water recirculang loop or system that ulizes exisng hot and cold lines or a
dedicated return line, and only acvates when hot water is used. It can be acvated by a push buon, moon sensor, or voice
acvaon but not by a temperature sensor. A mer added to a standard recirculang pump is not considered as on-demand.
[2] The air handler pump must be sized for the ow rate of the heat load, pressure losses through the air handler coil, pressure
losses though the Rinnai tankless water heater, and piping and components connecng the air handler and tankless unit. Refer
to the tankless water heater pressure loss curve and consult with the air
handler/component manufacturer for pressure loss informaon.
What Will Rinnai Do?
Rinnai will repair or replace the covered product or any part or component that is defecve in materials or
workmanship as set forth in the above table. Rinnai will pay reasonable labor charges associated with the repair
or replacement of any such part or component during the term of the labor warranty period. All repair parts
must be genuine Rinnai parts. All repairs or replacements must be performed by a qualied professional who is
properly trained to do the type of repair.
Replacement of the product may only be authorized by Rinnai at its sole discreon. Rinnai does not authorize
any person or company to assume for it any obligaon or liability in connecon with the replacement of the
product. If Rinnai determines that repair of a product is not possible, Rinnai may replace the product with a
comparable product at Rinnais sole discreon. The warranty claim for product parts and labor may be denied if
a component or product returned to Rinnai is found to be free of defects in material or workmanship; damaged
by improper installaon, use or operaon; or damaged during return shipping.
How to Obtain Service
For the name of a trained and qualied professional, please contact your place of purchase, visit the Rinnai
website (www.rinnai.us), call Rinnai at 1-800-621-9419 or write to Rinnai at 103 Internaonal Drive, Peachtree
City, Georgia 30269.
34 V53De Manual
Proof of purchase is required to obtain warranty service. You may show proof of purchase with a dated sales
receipt, or by registering within 30 days of purchasing the product. To register your Rinnai Tankless Water
Heater, please visit www.rinnai.us. For those without internet access, please call 1-800-621-9419. Receipt of
registraon by Rinnai will constute proof-of-purchase for this product. Registraon of product installed in new
home construcon may be veried with a copy of the closing papers provided by the inial home buyer.
However, registraon is not necessary in order to validate this Limited Warranty.
Accident, abuse, or misuse
Alteraon of the product or any component part
Misapplicaon of this product
Improper installaon (such as but not limited to)
Product being installed in a corrosive envi-
ronment
Condensate damage
Improper venng
Incorrect gas type
Incorrect gas or water pressure
Absence of a drain pan under the appliance
Improper maintenance (such as but not limited
to scale build-up, freeze damage, or vent
blockage)
Incorrect sizing
Any other cause not due to defects in materials
or workmanship
Problems or damage due to res, ooding,
electrical surges, freezing or any acts of God
Any damage caused by poor water quality
Operang the water heater with anything other
than potable water at all mes
Force majeure
What is Not Covered?
This Limited Warranty does not cover any failures or operang dicules due to the following:
There is no warranty coverage on product installed in a closed loop applicaon, commonly associated with space
heang only applicaons.
The integrated controller on indoor models has a 1 year warranty on parts.
There is no warranty coverage for commercial applicaons.
This Limited Warranty does not apply to any product whose serial number or manufacture date has been
defaced.
This Limited Warranty does not cover any product used in an application that uses chemically treated water such
as a pool or spa heater.
Limitation on Warranties
No one is authorized to make any other warranties on behalf of Rinnai America Corporation. Except as expressly
provided herein, there are no other warranties, expressed or implied, including, but not limited to warranties of
merchantability or fitness for a particular purpose, which extend beyond the description of the warranty herein.
Any implied warranties of merchantability and fitness arising under state law are limited in duration to the
period of coverage provided by this Limited Warranty, unless the period provided by state law is less. Some
states do not allow limitations on how long an implied Limited Warranty lasts, so the above limitation may not
apply to you.
Rinnai shall not be liable for indirect, incidental, special, consequential or other similar damages that may arise,
including lost profits, damage to person or property, loss of use, inconvenience, or liability arising from improper
installation, service or use. Some states do not allow the exclusion or limitation of incidental or consequential
damages, so the above limitation may not apply to you.
This Limited Warranty gives you specific legal rights, and you may also have other rights which vary from state to
state.
www.rinnai.us/warranty
NOTES
U340-1338(02)
100000561(03)
7/2019