Rinnai RLX94i User manual

Direct Vent Tankless Water
Heater Installaon and
Operaon Manual
—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 neighbor’s phone. Follow the gas supplier’s 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 4-30.
The consumer must read the enre manual to properly operate the water heater and to have regular maintenance
performed.
ANS Z21.10.3 ● CSA 4.3
FOR INDOOR APPLICATIONS ONLY
RL75i..................... REU-VC2528FFUD-US
REU-VC2528FFUD-US(A)
RLX94i................... REU-VC2737FFUD-US
RL94i..................... REU-VC2837FFUD-US
FOR OUTDOOR APPLICATIONS ONLY
RL75e.................... REU-VC2528WD-US
REU-VC2528FFUD-US(A)
RL94e.................... REU-VC2837WD-US
SANITATION
Low Lead Content
NSF/ANSI 372
CUS
U307-0710X03
060 00012 31315 4

2VC Series 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 ........................6
Freeze Protecon.............................................11
Checklist to Determine Installaon Locaon...12
Mount to Wall..................................................12
Remove the Front Panel .................................. 12
Installaon of Venng (indoor models only) ...13
Condensate (indoor models only)....................15
Checklist for Venng and Condensate
(indoor models only)........................................15
Installaon of Plumbing...................................16
Checklist for Plumbing .....................................19
Installaon of Gas Supply ................................19
Connect Electricity ...........................................21
Adjust for High Altude ...................................21
Adjust for Vent Length (indoor models only) .. 21
Checklist for Gas and Electricity.......................21
Installaon of Temperature Controller............22
Final Checklist...................................................24
Technical Data ........................................................25
Specicaons ...................................................25
Dimensions.......................................................26
Pressure Drop and Water Flow Curves............27
Ladder Diagram................................................28
Recirculaon Mode..........................................29
Operaon Instrucons .......................................31
Consumer Operaon Guidelines for the
Safe Operaon of your Water Heater..............32
How to Use the Temperature Controller .........33
How to Set the Temperature ...........................34
Diagnosc Codes..............................................36
Required Maintenance.....................................39
Freeze Protecon and Winterizaon ........40
Flushing the Heat Exchanger.....................41
Manual Draining of the Water Heater ......42
State Regulaons....................................................43
Replacement Parts .................................................44
Consumer Warranty ...............................................45
French Version........................................................48
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 your account with us.
If you have any quesons or feel that the manual is incomplete contact Rinnai at 1-800-621-9419.

VC Series Manual 3
CAUTION
BURN HAZARD. Hot exhaust and vent may cause
serious burns. Keep away from water heater unit.
Keep small children and animals away from the
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 below 36” 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
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.
Do not use substute materials. Use only parts
cered for the appliance.
Should overheang occur or the 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.
California law requires this noce to be provided:
California Proposion 65:
This product contains chemicals known to the state of California to cause cancer, birth defects, or other
reproducve harm.
WARNING

4VC Series Manual
A licensed professional must install the appliance,
inspect it, and leak test it before use. The warranty
will be voided due to any improper installaon.
The installer should have skills such as:
Gas sizing.
Connecng gas lines, water lines, valves, and
electricity.
Knowledge of applicable naonal, state, and
local codes.
Installing venng through a wall or roof.
Training in installaon of tankless water heaters.
(Training can be accessed on-line at
www.trainingevents.rinnai.us)
Installaon Instrucons
Installaon Steps
Prepare for Installaon ......................................5
Determine Installaon Locaon.........................6
Checklist to Determine Installaon Locaon...12
Mount to Wall..................................................12
Remove the Front Panel ..................................12
Installaon of Venng (indoor models only) ...13
Condensate (indoor models only)....................15
Checklist for Venng and Condensate
(Indoor models only)........................................15
Installaon of Plumbing ...................................16
Checklist for Plumbing .....................................19
Installaon of Gas Supply.................................19
Connect Electricity ...........................................21
Adjust for High Altude ...................................21
Adjust for Vent Length (indoor models only) ..21
Checklist for Gas and Electricity.......................21
Installaon of Temperature Controller............22
Final Checklist...................................................24
General InstruconsInstaller Qualicaons
DO NOT
Do not install the RL75i, RL94i, or the RLX94i
outdoors.
Do not install the RL75e or the RL94e 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.).
Type of installaon
For installaon in residenal and commercial
applicaons.
Cered for installaon in manufactured (mobile)
homes.

VC Series Manual 5
Prepare for installaon
Parts included
Tools needed
Materials needed
 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 and
those in Care and Maintenance 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.
 Should overheang occur or the gas supply fail to
shut o, turn o the manual gas control valve to
the appliance.
 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.
 Tankless water heater
 Color coded cold (blue) and hot (red) isolaon
valves
 Pressure relief valve
 MC-91-2 temperature controller (integrated into
indoor models; provided with outdoor models)
 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 or gas leak
detector soluon
 Approved venng
 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 and drain valves
General Instrucons (connued)

6VC Series Manual
Environment
Air surrounding the water heater, venng, and vent
terminaon(s) 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, venng, and vent terminaon(s)
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 FOR:
Indoor/Internal Water Heaters
 DO NOT Install in areas where air for combuson
can be contaminated with chemicals.
 Before installaon, consider where air has the
ability to travel within the building to the water
heater.
 Where possible, install the water heater in a sealed
closet so that it is protected from the potenal of
contaminated indoor air.
 Chemicals that are corrosive in nature should not
be stored or used near the water heater.
Outdoor/External Water Heaters and Vent
Terminaons of Indoor/Internal Water Heaters
 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 or vent
terminaon.
Damage and repair due to corrosive compounds in the
air is not covered by warranty.
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.
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
Determine Installaon Locaon
Water Quality
* Source: Part 143 Naonal Secondary Drinking Water
Regulaons
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on’s “ScaleCuer
Water Condioning System” that oers superior lime
scale prevenon and corrosion control by feeding a
blend of control compounds into the cold water
supply.
You must ensure that clearances will be met and that
the vent length will be within required limits. Consider
the installaon environment, water quality, and need
for freeze protecon. Requirements for the gas line,
water lines, electrical connecon, and condensate
disposal can be found in their respecve installaon
secons of this manual.
Part Number Descripon
103000038 Southeastern Filtratrion
ScaleCuer System 3/4” Feed
103000039 ScaleCuer Rell

VC Series Manual 7
INSIDE
CORNERDETAIL
FIXED
CLOSED
OPERABLE
FIXED
CLOSED
OPERABLE
B
B
B
A
J
BM
C
F
B
B
E
D
L
G
A
H
K
I
[1] A vent shall not terminate directly above a sidewalk or paved driveway
that is located between two single family dwellings and serves both
dwellings.
[2] Permied only if veranda, porch, deck, or balcony is fully open on a
minimum of two sides beneath the oor.
 For clearances not specied in ANSI Z223.1/NFPA 54, clearances are in
accordance with local installaon codes and the requirements of the gas
supplier.
Clearance to opposite wall is 24 inches (60 cm).
X
V
AIR SUPPLY INLET
VENT TERMINAL
AREA WHERE TERMINAL IS
NOT PERMITTTED
For indoor models, you must install a vent terminaon to bring in combuson air and expel exhaust.
SNOW
TERMINATION
Clearance in
Ref. A also
applies to
anticipated
snow line
Direct Vent (Indoor Unit) Other than direct vent (Outdoor unit)
Ref
Descripon
Canadian Installaons
(CSA B149.1)
US Installaons Canadian Installaons
(CSA B149.1)
US Installaons
(ANSI Z223.1 / NFPA 54)
AClearance above grade, veranda, porch, deck, or
balcony 12 inches (30 cm) 12 inches (30 cm) 12 inches (30 cm) 12 inches (30 cm)
BClearance to window or door that may be opened 36 inches (91 cm) 12 inches (30 cm)
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
CClearance 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
****
EClearance to unvenlated sot ****
FClearance to outside corner ****
GClearance to inside corner ****
HClearance to each side of center line extended
above meter/regulator assembly
3 feet (91 cm) within a
height 15 feet (4.5 m)
above the meter/
regulator assembly
*
3 feet (91 cm) within a height 15
feet (4.5 m) above the meter/
regulator assembly
*
IClearance to service regulator vent outlet 36 inches (91 cm) *36 inches (91 cm) *
J
Clearance to nonmechanical air supply inlet to
building or the combuson air inlet to any other
appliance
36 inches (91 cm) 12 inches (30 cm)
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
KClearance to a mechanical air supply inlet 6 feet (1.83 m)
3 feet (91 cm) above if
within 10 feet (3 m)
horizontally
6 feet (1.83 m)
3 feet (91 cm) above if
within 10 feet (3 m)
horizontally
LClearance above paved sidewalk or paved
driveway located on public property 7 feet (2.13 m) *7 feet (2.13 m) *
MClearance under veranda, porch, deck, or balcony 12 inches (30 cm)  *12 inches (30 cm)  *
Terminal Clearances

8VC Series Manual
24"
V
Check to determine whether local codes supersede
these clearances.
 Avoid terminaon locaons near a dryer vent.
 Avoid terminaon locaons near commercial
cooking exhaust.
 You must install a vent terminaon at least 12
inches above the ground.
60"
V
V
(1.52 m)
between
terminals at
dierent levels
(0.61 m) to wall or parapet
(0.30 m) between
terminals at same
level
12"
V V
(1.52 m) vercally
between terminals
V
60"
V
Addional clearances - RL75i, RL94i, RLX94i
12"
12"
36"
INSIDE
CORNER
V V
(0.30 m ) to
an inside
corner (0.30 m) between
terminals at same
level
Important consideraons for locang vent
terminaon under a sot (venlated or unvenlated
or eave vent; or to a deck or porch)
 Do not install vent terminaon under a sot vent
such that exhaust can enter the sot vent
 Install vent terminaon such that exhaust and
rising moisture will not collect under
eaves. Discoloraon to the exterior of the
building could occur if installed too close.
 Do not install the vent terminaon too close
under the sot where it could present
recirculaon of exhaust gases back into the
combuson air intake part of the terminaon.

VC Series Manual 9
2"
12"
60"
36"
Local codes supersede these clearances.
 Avoid terminaon locaons near a dryer vent.
 Avoid terminaon locaons near commercial
cooking exhaust.
 Avoid terminaon locaons near any air inlets.
Addional clearances
RL75e, RL94e
(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

10 VC Series Manual
Unit clearances
* 0 inches from vent components and condensate
drain line.
The clearance for servicing is 24 inches in front of the
water heater.
For closet installaon, clearance is 6 inches (152 mm)
from the front of the water heater.
Indoor models: RL75i, RL94i, RLX94i Outdoor models: RL75e, RL94e
The clearance for servicing is 24 inches in front of the
water heater.
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)
to Combusbles
inches (mm)
to Non-
Combusbles
inches (mm)
Top of Heater 6 * (152) 2 *(51)
Back of Heater 0 (zero) 0 (zero)
Front of Heater 6 (152) 6 (152)
Sides of Heater 2 (51) 1/2 (13)
Ground/Boom 12 (305) 12 (305)
Vent 0 (zero) 0 (zero)