Rinnai Circ-Logic RL75i 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(A)-US
RL94i..................... REU-VC2837FFUD-US
FOR OUTDOOR APPLICATIONS ONLY
RL75e.................... REU-VC2528WD-US
REU-VC2528WD(A)-US
RL94e.................... REU-VC2837WD-US

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
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
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 you 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 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.
California law requires this noce to be provided:
California Proposion 65 lists chemical substances known to the state to cause cancer, birth defects, death,
serious illness or other reproducve harm. This product may contain such substances, be their origin from fuel
combuson (gas, oil) or components of the product itself.
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 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.
 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.

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 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.
 installing venng through a wall or roof
If you lack these skills contact a licensed professional.
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 or the RL94i 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 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

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.
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
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 provides a “Scale Control 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.
103000022 103000023 103000024
Installed on cold
water line supplying
1 tankless water
heater only
Whole home or Light
Commercial supply-
ing 1 tankless water
heater
Whole home supply-
ing 2 tankless water
heaters or 1 tankless
in Light Commercial
Rell 103000025 Rell 103000026 Rell 103000026

VC Series Manual 7
Vent Terminaon Clearances
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
Ref Descripon Canadian Installaons US Installaons
AClearance above grade, veranda, porch, deck, or balcony 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)
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/ *
IClearance to service regulator vent outlet 36 inches (91 cm) *
JClearance 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)
KClearance to a mechanical air supply inlet 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) *
MClearance under veranda, porch, deck, or balcony 12 inches (30 cm)  *

8VC Series Manual
24"
V
Check on 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 from 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
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.
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.
Indoor models: RL75i, RL94i 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)

VC Series Manual 11
Freeze Protecon
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
covered 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 –22°F (-30°C) for indoor models or is as cold as –4°F
(-20°C) for outdoor models, when protected from
direct wind exposure. Because of the “wind-chill”
e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. (The
condensate trap drain plug and water drain plug
are not aected by the auto drain down solenoid
valves and will have to be manually opened.)
 a surge protector with terminals is installed which
allows the solenoid valves to operate if the unit is
disabled due to a diagnosc code. This is
available as 104000057.
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.
Maximum vent length
(indoor models only)
1. Determine the number of 90 degree elbows in
the vent system. (Two 45 degree elbows count as
one 90 degree elbow.)
2. Refer to the table to nd the maximum vent
length based on the number of elbows.
3. Adjust switch No. 1 in the SW1 DIP switch (tan
switches) if required by the applicable note.
 If the length is greater than 21  (6.4 m) then
move switch No. 1 (SW1) to OFF.
 If the length is greater than 15  (4.6 m) then
move switch No. 1 (SW1) to OFF.
 If the length is greater than 9  (2.7 m) then move
switch No. 1 (SW1) to OFF.
Move switch No. 1 (SW1) to OFF.
Example: If you have one elbow then your maximum
vent length is 35 feet (10.7 m). If your
actual length is greater than 15  (4.6 m)
then move switch no. 1 (SW1) to OFF.
Number of
90° Elbows
Maximum vent length
041  (12.5 m) 
135  (10.7 m) 
229  (8.8 m) 
323  (7.0 m) 
417  (5.2 m) 
511  (3.4 m) 
65  (1.5 m) 
If you have a longer vent length (see above), switch
No. 1 is required to be in the OFF posion. This
ensures the water heater will run properly. Blocked
ue diagnosc codes and shutdowns may result if
switch No. 1 is not in the correct posion.
NOTICE

12 VC Series Manual
Mount to Wall
wall installaon
brackets
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.
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.
□For indoor models, the planned venng will not
exceed the maximum length for the number of
elbows used.
□The planned venng terminaon/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 standard 3 prong 120 VAC, 60 Hz properly
grounded wall outlet (for indoor models) or other
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 water
heater (indoor models), temperature controller
(outdoor models), or give the enre manual
directly to the consumer.
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.

VC Series Manual 13
Manufacturer Listed and Tested Vent Products Telephone Fax Contact
Ubbink Rolux Vent System 800-621-9419 678-829-1666 www.rinnai.us
Heat-Fab Saf-T Vent SC system 800-772-0739 413-863-4803 [e-mail],
www.heaab.com
Metal-Fab Corr/Guard Vent/Air Intake System 800-835-2830 316-943-2717 [email protected],
www.metal-fabinc.com
Installaon of venng (indoor models only)
Install the correct venng for your model according to the venng manufacturer’s instrucons and the
guidelines below.
Refer to the manufacturer’s technical literature for specic part numbers and instrucons.
Venng Guidelines
DO NOT
 Do not use PVC, CPVC, ABS or galvanized material
to vent this appliance.
 Do not combine vent components from dierent
manufacturers.
 Vent diameter must not be reduced.
 Do not connect the venng system with an
exisng vent or chimney.
 Do not common vent with the vent pipe of any
other water heater or appliance.
MUST DO
 This water heater is a direct vent water heater and
therefore is cered and listed with the vent
system. You must use vent components that are
cered and listed with the water heater model.
 The vent system must vent directly to the outside
of the building and use outside air for combuson.
 Avoid dips or sags in horizontal vent runs by
installing supports per the vent manufacturer’s
instrucons.
 Support horizontal vent runs every four feet and
all vercal vent runs every six feet or in
accordance with local codes.
 Venng should be as direct as possible with a
minimum number of pipe ngs.
 Vent connecons must be rmly pressed together
so that the gaskets form an air ght seal.
 The vent piece connected to the water heater
must be secured with one self-tapping screw.
INFORMATION
 Refer to the instrucons of the vent system
manufacturer for component assembly
instrucons.
 If the vent system is to be enclosed, it is suggested
that the design of the enclosure shall permit
inspecon of the vent system. The design of such
enclosure shall be deemed acceptable by the
installer or the local inspector.
NOTICE
If it becomes necessary to access an enclosed vent
system for service or repairs, Rinnai is not responsible
for any costs or dicules in accessing the vent
system. The warranty does not cover obtaining
access to a vent system in an enclosed environment.

14 VC Series Manual
Flue Installaon (indoor models only)
Vercal Terminaon
(condensate collector must be used in all installaons)
3 in (75 mm)
minimum
3 in (75 mm)
minimum
Horizontal Terminaon using the
Condensate Collector
3 in (75 mm)
minimum
Condensate
Trap
To adjust the condensate collector posion or to
replace the female vent top with a male vent top:
1. Loosen the 4 screws at the rear bracket
2. Slide the bracket away from the female vent top.
3. Remove the 4 screws aaching the female vent top
to the water heater.
4. Li up the female vent top and reposion as desired
(or replace with a male vent top).
5. Install the 4 screws at the vent top and ghten the 4
screws at the bracket.
Secure the rst vent component to the water heater
with one self-tapping screw at the hole located above
the condensate collector.
Bracket
Condensate Collector
Securing Screw
Horizontal Terminaon without using the Condensate Collector
Maximum Height *
5 feet (1.52 m)
Regions of cold climate will create more
condensate in the vent system. The
condensate collector should be used in
cold climates.
If more than one elbow is used in the
vercal secon the condensate collector
must be used.
* The condensate collector must be used in
horizontal terminaons if a vercal rise in
the vent system exceeds 5.
If the condensate collector is not used, the drain pipe
must be capped to prevent exhaust gases and
condensate from entering the building. The cap is
supplied on the appliance.
WARNING
Install the venng terminaon according to the diagrams and instrucons below.

VC Series Manual 15
Condensate
(indoor models only)
Condensate formaon can occur in high eciency
direct vent appliances. Without proper drainage
condensate will damage the heat exchanger.
To prevent condensate damage follow these
instrucons.
DO NOT
 Do not allow condensate to enter the water
heater.
 Do not connect the condensate drain pipe directly
to the rain sewer.
 Do not connect the condensate drain line with an
air condioning evaporator coil drain.
MUST DO
 Use only vent that is approved and idened as
acceptable for your parcular model.
 For vercal terminaons, install a condensate drain
and trap as close as possible to the appliance.
 Slope the venng toward the appliance according
to the vent manufacturers installaon instrucons.
 All condensate must drain and be disposed of
according to local codes.
 Use only corrosion resistant materials for the
condensate drain lines such as PVC pipe or plasc
hose.
 The condensate drain pipe (along its enre length)
must be at least the same diameter as the drain
line, (5/8 inch NPT).
 The end of the condensate drain pipe should be
open to the atmosphere. The end should not be
under water or other substances.
 To minimize freezing of the condensate, run the
condensate drain line through an interior wall or
between insulaon and an interior wall.
 The condensate collector should be used for all
hydronic heang applicaons.
Checklist for Venng and
Condensate (indoor models only)
□Verify proper clearances around the vents and air
intakes.
□Ensure you have used the correct venng
products for the model installed and that you
have completely followed the venng
manufacturer’s installaon instrucons and these
installaon instrucons.
□Verify that the vent pipe has a downward slope or
grade to the outside of 1/4 inch per foot (1.2° )
OR if the vent pipe is sloped toward the water
heater (as some local codes require), that a
condensate collector is installed to allow
condensaon to drain away from the water
heater to a proper drain source.
□Verify that condensate will not be allowed to
drain back into the water heater.
□Verify that the vent system does not exceed the
maximum length for the number of elbows used.
INFORMATION
 A condensate trap is available, P/N 222053.
 Regions of cold climate will create more
condensate in the vent system. The condensate
collector should be used in cold climates.
 The condensate drain pipe should be as short as
possible and have a downward pitch.

16 VC Series Manual
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 nonpotable 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 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 manufacturer’s 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
Isolaon valves are included with this water heater.
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 structure’s 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.

VC Series Manual 17
Isolaon Valves and Pressure Relief Valve
The isolaon valves provide the ability to isolate the
water heater from the structure’s plumbing and allow
quick access to ush the heat exchanger. Check with
local codes to determine if a pressure and
temperature relief valve is required. The included
valves meet American Naonal Standard (ANSI
Z21.10.3) / Canadian Standard (CSA 4.3) and are
ANSI/NSF 61 approved for potable water.
Isolaon Valves Installaon Instrucons:
1. Wrap the ends of the threaded water inlet &
outlet on the tankless water heater, as well as
the threaded end of the approved pressure relief
valve with a minimum of 5 wraps of Teon®
tape.
2. Screw the pressure relief valve into the 3/4”
threads opposite the wing handle on the HOT
water service valve. (RED drain handle) (see
Pressure Relief Valve Secon for proper
installaon requirements)
3. Loosen the 3/4” union nut on the HOT water
valve and connect to the HOT water outlet on
the tankless water heater. If nut is removed,
ensure that you realign the tailpiece accurately
to the valve and that the black washer is
posioned such that the raised metal edge of
the valve is inside the washer.
4. Align the direcon of the HOT water drain to the
desired posion.
5. Tighten the union assembly to the HOT water
valve using approximately 15 foot lbs of torque.
6. Repeat steps 3-5 for the COLD water valve.
(BLUE drain handle) for connecon to the COLD
water inlet on the tankless water heater.
7. Connect the INLET on the COLD water valve to
the MAIN SOURCE of the water supply.
8. Connect the OUTLET on the HOT water valve to
the HOT WATER plumbing system.
9. Ensure that both drain valve lever handles are in
the closed posion (perpendicular to the drain
poron of the body).
Pressure Relief Valve Installaon Instrucons:
The PRV must be connected by the threaded
connecon opposite the wing handle on the hot
water valve (designated by the RED drain handle) or
the threaded connecon on the side of the relocaon
ng above the hot water valve. Installaon must
maintain a ¾” port size with no shut o valve or line
restricon in-between the appliance and the PRV. The
discharge line from the PRV should pitch downward
and terminate 6” above drains where discharge will
be clearly visible. The discharge end of the line shall
be plain (unthreaded) and a minimum of ¾” in
diameter. The discharge line material must be
suitable for water at least 180° Fahrenheit and can be
no more than 30 feet in length and contain no more
than 4 elbows or bends. No valve of any type may be
installed in the discharge line of the pressure relief
valve.
Pressure Relief Valve Maintenance:
For proper care of this approved pressure relief valve,
it is recommended that the valve is manually
operated 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.
Please note that only the PRV in this package is
cered by CSA Internaonal as an approved item.
APressure Relief Valve (PRV)
BPRV Discharge Outlet
CHot Ball Valve Drain Handle
DCold Ball Valve Drain Handle
A
B
C
D

18 VC Series Manual
Piping Diagram for Basic Installaon
GasSup
ply
3/4"C
oldWate
rSupply
Line
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
asConne
ction
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.

VC Series Manual 19
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 water supply to the tankless water heater
on the 3/4” MNPT connecon at the boom of
the unit marked “Water Inlet”, which is the cold
water supply.
2. Plumb the building hot water supply to the 3/4”
MSPT connecon marked “Water Outlet”, which
is the hot water supply.
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 50 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
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.

20 VC Series 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 siz-
ing 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 applica-
ble 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 lo-
ca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/FT3. The gas input of the RL94i is 199,000
BTU/HR. Addional appliances at the locaon require
65,000 BTU/hr. Therefore the cubic feet per hour =
(199,000 + 65,000) / 1000 = 264 FT3/HR. If the pipe
length is 10 feet then the 3/4 inch pipe size is capable
of supplying 264 FT3/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 11 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 11 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