Rinnai RUCS65i series User manual

Direct Vent Tankless Water Heater
— Do not store or use gasoline or other flammable 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.
•
•If you cannot reach your gas supplier, call the fire department.
—
may result causing property damage, personal injury, or death.
WARNING
READ ALL OF THE INSTRUCTIONS THOROUGHLY BEFORE INSTALLING OR OPERATING THIS WATER HEATER.
safety
performed.
ANSI Z21.10.3 •CSA 4.3
FOR INDOOR APPLICATIONS ONLY
RUCS65i ................ REU-KCM2025FFU-US
RUCS75i ................ REU-KCM2528FFU-US
FOR OUTDOOR APPLICATIONS ONLY
RUS65e ................. REU-KCM2025W-US
RUS75e ................. REU-KCM2528W-US
SANITATION
Low Lead Content
NSF/ANSI 372
C US
U328-0700(00)
060 00012 32698 7

2 KCM Series Manual
Table of Contents
and others.
injury or death.
injury or death.
DANGER
CAUTION
WARNING
Table of Contents ..................................................... 2
Consumer and Installer ............................................ 3
(for the licensed professional) ............................. 4
......................................5
........................6
.............................................10
...11
Mount to Wall..................................................11
Remove the Front Panel ..................................11
...12
......................13
.............20
Condensate ......................................................37
(indoor models only)........................................37
...................................38
Checklist for Plumbing .....................................41
................................41
Connect Electricity ...........................................43
......43
Adjustment for Vent Length
(indoor models only)........................................43
Checklist for Gas and Electricity
Installaon of Oponal Temperature
Controller
.......................43
44
Final Checklist...................................................46
Technical Data ........................................................
.........................................................
47
...................................................47
Dimensions.......................................................48
Pressure Drop and Water Flow Curves ............49
Ladder Diagram................................................50
.......................................51
....................52
How to set the Temperature .................................53
Controller ........................................................54
....................................................56
Required Maintenance...........................................59
...............60
Flushing the Heat Exchanger............................61
Manual Draining of the Water Heater .............62
....................................................63
Replacement Parts .................................................64
Warranty.................................................................65
French Version........................................................67
NOTICE:
or your account with us.
-800-621-9419.

KCM Series Manual 3
CAUTION
 BURN HAZARD. Hot exhaust and vent may cause
serious burns. Keep away from the 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.

 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.
 Proper venng is required for the safe operaon of
this appliance.
California law requires this noce to be provided:

This product contains chemicals known to the state of California to cause cancer, birth defects, or other
reproducve harm.
WARNING

4 KCM Series Manual
A licensed professional must install the appliance,
inspect it, and leak test it before use. The warranty
The installer should have skills such as:
•Gas sizing.
•
electricity.
•
local codes.
•
•
(Training can be accessed on-line at
www.trainingevents.rinnai.us)
......................................5
.........................6
.............................................10
...11
Mount to Wall..................................................
......................................................
11
Remove the Front Panel ..................................11
...12
Condensate 37
............37
...................................38
Checklist for Plumbing .....................................41
.................................41
Connect Electricity ...........................................43
......43
Adjustment for Vent Length
(indoor models only)........................................43
Checklist for Gas and Electricity.......................
Installaon of Oponal Temperature
Controller
43
44
Final Checklist...................................................
.........................................................
46
DO NOT
•Do not install the RUCS65i, or the RUCS75i
outdoors.
•Do not install the RUS65e, or the RUS75e indoors.
•Do not install the appliance in an area where water
damage to the area adjacent to the appliance or to
cannot be avoided, it is recommended that a
suitable drain pan, adequately drained, be installed
under the appliance. The pan must not restrict
•
supplied from occupied spaces.
•
a pool or spa heater that uses chemically treated
water . (This appliance is suitable for filling large or
whirlpool spa tubs with potable water.)
•
for this appliance.
MUST DO
•
in the absence of local codes, with the
Fuel Gas Code, ANSI Z223.1/NFPA 54, or the
B149.1. If installed in a manufactured home, the
Manufactured
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
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
at test pressures in excess of 1/2 psi (3.5 kPa)
(13.84 in W.C.).
•
•
homes.
(for the licensed professional)

KCM Series Manual 5

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.

 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
 Self Tapping Screws (Qty - 2)
 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
 Pressure Relief Valve
 Heat tape
 Pipe insulaon
 Electrical wire and
conduit per local code
 Concrete wall anchors
 Oponal pipe cover
 Oponal temperature
controller (MC-91-2)
 PVC glue/cement
 5/8” ID PVC exible
tubing
 2 conductor 22 AWG
wire for controller
 Single gang electrical
box
 Wire nuts
 Unions and drain valves
 Isolaon Valve Kit


6 KCM Series Manual
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 affect or damage the
heat exchanger. Water that contains chemicals
exceeding the levels below affect 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
Environment
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
is recommended that outdoor models be used for these
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 that may contain
strongly recommended.
IMPORTANT CONSIDERATIONS FOR:
Indoor/Internal Water Heaters
•
might be contaminated with chemicals.
•
ability to travel within the building to the water
heater.
•Where possible, install the water heater in a sealed
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
•Install the water heater as far away as possible
from exhaust vent hoods.
•Install as far away as possible from any 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
Damage and repair due to corrosive compounds in the
air is not covered by warranty.
Water Quality
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 may require more frequent
heat exchanger flushing schedule.
When scale build-up in the heat exchanger begins to
controller is installed, diagnosc code "LC#" will display
on controller.
Without a controller, "LC" will display on status monitor.
Flush the heat exchanger to prevent damage to it. Scale
build up is caused by hard water and can be accelerated
if the unit is set at a high temperature.
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
Part Number
103000038 Southeastern Filtratrion
103000039
when a

KCM Series Manual 7
INSIDE
CORNERDETAIL
FIXED
CLOSED
OPERABLE
FIXED
CLOSED
OPERABLE
B
B
BA
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 to the outside.
SNOW
TERMINATION
Clearance in
Ref. A also
applies to
anticipated
snow line
   
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/
regulator assembly
*
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)  *
Direct Vent Terminal Clearances (Indoor Units)

8KCM Series Manual
Other Than Direct Vent Terminal Clearances (Outdoor Units)
INSIDE
CORNERDETAIL
FIXED
CLOSED
OPERABLE
FIXED
CLOSED
OPERABLE
B
B
BA
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
   
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
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 **
DVer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 *
IClearance to service regulator vent outlet 36 inches (91 cm) *
JClearance 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
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)  *
Clearance in
Ref. A also
applies to
ancipated
snow line

KCM Series Manual 9
Check to determine whether local codes supersede
these clearances.
•
•
cooking exhaust.
•
•
level.
(0.30 m) between
terminals at same
level
(1.52 m)
between
terminals
60"
V
V
(1.52 m)
between
terminals at
different levels
24"
V
(0.61 m) to wall or parapet
12"
V V
V
60"
V
RUS65e, RUS75e
RUCS65i, RUCS75i
The vent for this appliance shall not terminate
•Over public walkways; or
•Near soffit vents or crawl space vents or other
area where condensate or vapor could create a
nuisance or hazard or cause property damage; or
•Where condensate or vapor could cause damage
regulators, relief valves, or other equipment.
or eave vent; or to a deck or porch)
•
such that exhaust can enter the soffit vent
•
will not collect under eaves.
the building could occur if installed too close.
•
2"
12"
60"
36"
(0.91 m) to
or eve vent; or to a
deck or porch
between terminals
(50 mm) between
terminals at same level
(0.30 m) to an
inside corner
12"
12"
36"
INSIDE
CORNER
VV
(0.30 m) between
terminals at same
level
(0.30 m ) to
an inside
corner

10 KCM Series Manual
Unit clearances
Indoor models:
RUCS65i,
RUCS75i
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)
* 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.
Outdoor models:
RUS65e, RUS75e 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)
The clearance for servicing is 24 inches in front of the
water heater.
Freeze Protecon
Make sure that in case of freezing weather the water
heater and its water lines are protected to prevent
freezing. Damage due to freezing is not covered by
the warranty.
With electrical power and gas 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 protect itself from freezing.
In the event of a power failure and/or gas
interrupon 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.
Loss of freeze protecon may result in water damage
from a burst heat exchanger or water lines.
The unit may be drained manually. However, it is
highly recommended to:
 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.)
 a surge protector with terminals be purchased
and 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 of the water heater
will not prevent the external piping from freezing. It
is recommended that hot and cold water pipes be
insulated. Pipe cover enclosures may be packed with
insulaon for added freeze protecon.
It is recommended that the condensate trap drain line
be insulated. A frozen condensate trap results in a
diagnosc code 25.

KCM Series Manual 11

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 of the
water heater. Refer to the weight of the water
heater in the Specicaons secon of this
manual.
Use a leveling tool to ensure that the water
heater is level. Proper operaon requires that
the water heater be level.


□The water heater is not exposed to corrosive
compounds in the air.
□The water heater locaon complies with all
required 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 all required clearances.
□Indoor air is not being used for combuson.
□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.
□



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.
NOTICE
The water heater must be installed in an upright
posion. Do not install upside down or on its side.

12 KCM Series Manual

Install the correct venng for your model according to the venng manufacturer’s instrucons and the guidelines
below. Refer to the vent manufacturer’s technical literature for specic part numbers and instrucons.
   
Ubbink Rolux 184162PP 223176PP, 223177PP
Centrotherm InnoFlue ICRT3539 ISELL0387UV
Heat-Fab Saf-T Vent Saf-T Vent CI Plus Wall
Terminaon Saf-T Vent CI Plus Rain Cap
Metal-Fab Corr/Guard 3CGRVDK 3CGRVT
Ipex Concentric Kit 3”- 196006 /197009 3”- 196006 / 197009
Ipex Low Prole Terminaon Kit —3”- 196985
4”- 196986
Various
Manufacturers
Schedule 40 PVC DWV Solid
Core Pipe (or approved equal)
CPVC schedule 40
Reference “Approved PVC/CPVC
Vent Conguraons” Table
Reference “Approved PVC/
CPVC Vent Conguraons”
Table
 
   
Ubbink Rolux Condensing
Vent System 800-621-9419 678-829-1666 www.rinnai.us
Centrotherm InnoFlue Vent System (single
wall SW, 3 inch diameter) 877-434-3432 518-618-3166
[e-mail]
www.centrotherm.us.com
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
Ipex Concentric Kit / Low Prole
Terminaon Kit
U.S. - 800-463-9572
CA. - 866-473-9462 —www.ipexamerica.com www.ipexinc.com
Various
Manufacturers
Schedule 40 PVC DWV Solid Core
Pipe (or approved equal)
CPVC schedule 40
———
Approved Vent Manufacturers
Approved Vent Products


KCM Series Manual 13
Venng Guidelines

 Do not use cellular core PVC/CPVC.
 Do not use Radel, ABS, or galvanized material to
vent this appliance.
 Do not cover non-metallic vent pipe and ngs
with thermal insulaon.
 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.

 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.

 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 permit inspecon
of the vent system. The design of such enclosure
shall be deemed acceptable by the installer or the
local inspector.

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.

 
Concentric OFF
Twin Pipe ON

Prior to the installaon of the vent system, the dip
switches on the PCB board must be properly set for
the venng conguraon selected for the applicaon.
(Unit comes defaulted for concentric applicaons)

-
-



14 KCM Series Manual

 Prior to the installaon of the vent system, the
unit must be properly adjusted for the venng
conguraon selected for the applicaon.
 Any issues resulng from improper installaon
will not be covered by warranty.
 Ducted outside air is mandatory for all twin pipe
conguraons.
NOTICE
Exhaust Adapter
Ring to be removed
and discarded for
concentric vent
conguraon
Concentric Vent Conguraon
(Same procedure to be used for Twin Pipe with
Centrotherm Adapter Conguraon)
Removal of Exhaust Adapter Ring
1. Remove fastener from concentric ue
connecon.
2. Remove exhaust adapter ring.
3. Install the concentric vent. Ensure it is properly
seated.
4. Secure the vent pipe to the unit with a screw

KCM Series Manual 15
Intake Cap to be removed and discarded
for twin pipe PVC/CPVC conguraon.

Removal of Intake Cap
1. Remove the fastener from intake connecon.
2. Remove the intake cap.
Twin Pipe PVC/CPVC Conguraon
(3”or 4”)
3. Install the intake pipe. Ensure it is properly
seated.
4. Secure the intake pipe to the unit with the
supplied screw (in the carton box).
5. Install the exhaust pipe. Ensure it is properly
seated.
6. Secure the exhaust pipe to the unit with the
supplied screw (in the carton box).

apply PVC glues, solvents, or cleaners
to the water heaters intake or exhaust gasket
connecons. Failure to correctly assemble the
components according to these instrucons
may result in property damage, personal injury,
or death.
Intake Gasket Connecon
Exhaust Gasket Connecon

16 KCM Series Manual
Maximum vent length

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 SW1 in DIPSW 1 (tan switches) if required
by the applicable note.
 If the length is greater than 21  (6.4 m) then
move SW1 to OFF.
 If the length is greater than 15  (4.6 m) then
move SW1 to OFF.
 If the length is greater than 9  (2.7 m) then move
SW1 to OFF.
Move 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 SW1 in DIPSW 1 to OFF.
If you have a longer vent length (see number 3
regarding max. vent length), SW1 in DIPSW 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 SW1 in
DIPSW 1 is not in the correct posion.


(Intake is the short UV protected 90° elbow)








If length is greater
than:
041  (12.50 m) 18  (5.49 m) move
SW1 to OFF
126  (7.93 m) 3  (0.91 m) move SW1
to OFF
211  (3.35 m) move SW1 to OFF for
any length








If length is greater
than:
041  (12.50 m) 21  (6.40 m) move
SW1 to OFF
135  (10.67 m) 15  (4.57 m) move
SW1 to OFF
229  (8.84 m) 9  (2.74 m) move
SW1 to OFF
323  (7.01m) 3  (0.91 m) move
SW1 to OFF
417  (5.18 m)
move SW1 to OFF
for any length
511  (3.35 m)
65  (1.52 m)

(Intake is the long UV protected 90° elbow)

InnoFlue Vent System (single wall SW, 3 inch diameter)

(90° elbow is equivalent to 6 feet; 45° elbow is equivalent to 3 feet.)




041 (12.5)1
135 (10.7)2
229 (8.8)3
323 (7.0)4
417 (5.2)4
511 (3.4)4
65 (1.5)4

KCM Series Manual 17
Maximum vent length

(90° elbow is equivalent to 5 feet; 45° elbow is equivalent to 2.5 feet.)




041 (12.5)**
136 (11.0) **
231 (9.4) **
326 (7.9) **
421 (6.4) **
516 (4.9) **
611 (3.4) **
**SW 1 in DIPSW 1 is “OFF” for lengths greater than
or equal to 21 feet.

(90° elbow is equivalent to 5 feet; 45° elbow is equivalent to 2.5 feet.)




0100 (30.5)**
195 (29.0) **
290 (27.4) **
385 (25.9) **
480 (24.4) **
575 (22.9) **
670 (21.3) **

(See Twin Pipe PVC/CPVC Vent Installaon secon for
more informaon regarding equivalent vent length
calculaons.)

18 KCM Series Manual
Flue Installaon with Concentric Venng (indoor models only)
Install the venng terminaon according to the diagrams and instrucons below.
Secure the first vent component to the water heater
with one self-tapping screw at the hole.


Slope the venting 1/4” per foot toward the
appliance according to the vent manufacturers
installation instructions.
Dispose of condensate per local codes.
Securing Screw
Slope the venting 1/4” per foot toward the
appliance according to the vent manufacturers
installation instructions.
Dispose of condensate per local codes.

KCM Series Manual 19
 Comply with the exhaust clearances found in this Rinnai Installaon and Operaon Manual.
 Only one appliance can be aached to the vent system.
 Install the system according to the Centrotherm installaon instrucons included with the vent system.
 The vent terminaon and air intake must be in the same pressure zone.
 Do not exceed the maximum straight vent length with number of elbows as shown in the tables in the
following secon.
 Maintain the clearances shown in the gures below.
 The following vent materials are for use with this appliance:
 Cellular core PVC/CPVC
 Radel, ABS, and/or Galvanized ducts.
Failure to use approved vent materials can result in property damage, personal injury, or death.

Flue Installaon with Centrotherm Venng (indoor models only)
Install the venng terminaon according to the diagrams and instrucons below.

11”
5”
Intake
Oponal
Vent
Slope horizontal exhaust run towards the water heater 1/4” per foot. slope combuson air pipe towards unit. Be
sure to dispose of condensate per local codes.

20 KCM Series Manual
Installaons must comply with local requirements and with the Naonal Fuel Gas Code, ANSI Z223.1/NFPA 54 for U.S.
installaons or CSA B149.1 for Canadian installaons.  use cellular core PVC, CPVC, or Radel based pipe materials
for the exhaust vent. Vents  be of solid core pipes ONLY.

Use only the materials listed in this secon for vent, air intake pipe, and ngs (See vent and air piping materials table).
Failure to comply with this warning could result in property damage, personal injury, or death.

Twin Pipe PVC/CPVC Vent Installaon