Rinnai CHS199100CU Operating instructions

Rinnai Commercial Hybrid System Installaon and Operaon Manual
INSTALLATION AND OPERATION MANUAL
Demand Duo™
Commercial Hybrid Water Heang System
1-800-621-9419
rinnai.us
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.
• 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 qualied installer, service agency or the gas supplier.
WARNING WARNING
Demand Duo™ Model
CHS199100CU

Contents
READ AND SAVE THESE INSTRUCTIONS
1. Welcome .........................................................3
2. Safety ..............................................................4
Safety Symbols ....................................................4
Safety Precauons...............................................5
3. About ..............................................................6
Specicaons.......................................................6
Dimensions and Connecons..............................7
4. Installaon ...........................................................8
Installaon Guidelines.........................................8
Typical Installaon Illustraons ..........................9
Unpack the Demand Duo™ ..............................10
Choose an Installaon Locaon .......................11
Transporng the Demand Duo™.......................13
Earthquake Strapping Instrucons....................13
Installaon Locaon Checklist ..........................14
5. Venng..........................................................15
Venng Guidelines ............................................15
Venng Installaon Sequence...........................16
Terminaon Consideraons..............................16
Select a Vent Type.............................................17
6. System Plumbing ......................................... 35
Pressure Relief Valve Requirements .................35
PRV Temperature Requirements .....................35
Piping Diagram for Basic Installaons...............36
Piping Diagram for Mulple Unit Installaons .37
Connect Water Heater to the Water Supply ....38
Fill the System ..................................................38
Condensate .......................................................39
7. Gas Supply..................................................... 41
Connect the Gas Supply ....................................41
8. Power Supply................................................43
9. Post-Installaon Checklist .............................45
10. Maintenance............................................... 46
11. Appendices ..................................................47
Service/Maintenance Log..................................47
Replacement Parts ...........................................48
Warranty ...........................................................49
12. Notes........................................................... 51

Rinnai Commercial Hybrid System Installaon and Operaon Manual 3
If You Need Service
Contact your local dealer/distributor or call Rinnai
Customer Care at:
1-800-621-9419
Please have your full serial number or model number
available for product- or service-related issues.
Thank you for purchasing Rinnai’s Demand Duo™
Commercial Hybrid Water Heang System. This manual
provides informaon on the installaon, operaon, and
maintenance of Rinnai’s Demand Duo™ Commercial
Hybrid Water Heang System. Read this manual
completely before installing or operang the system.
This manual is a supplement to the Installaon and
Operaon Manual for Commercial CU199 Condensing
Tankless Water Heaters; refer to the CU199 manual for
complete water heater details, including:
• Parameter Sengs (High Altude Adjustment, Vent
Length Adjustment, and more)
• Temperature Controller Installaon
• Performance Data
• Diagnosc Codes
To The Installer
• A trained and qualied professional must
install the system, inspect it, and leak test it
before use. The warranty will be voided due to
any improper installaon.
• The trained and qualied professional should
have skills such as:
 Gas line 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 on Rinnai Tankless Water
Heaters is accessible at
www.trainingevents.rinnai.us.
• Read all instrucons in this manual before
installing the system. The system must be
installed according to the exact instrucons in
this manual.
Welcome
1
To The Consumer
• You must read the enre manual to properly
operate the water heater and to have regular
maintenance performed.
• Keep this manual for future reference.
• As when using any appliance generang heat, there
are certain safety precauons you should follow.
See the Safety Precauons secon for detailed
safety precauons.
• Be sure your water heater is installed by a licensed
installer.
• If installing in the state of Massachuses, you must
read the Massachuses State Gas Regulaons
secon in the Installaon and Operaon Manual for
Commercial CU199 Condensing Tankless Water
Heaters (supplied with tankless water heater).
For Your Records
Dealer Name:
Dealer Phone #:
Purchase Date:
Tank Serial #:
System Serial #:
Tank Serial
Number Label
System Serial
Number Label
• Proper installaon is the responsibility of the
installer.
• When installaon is complete, leave this manual
with the system or give the manual directly to the
consumer.

4Rinnai Commercial Hybrid System Installaon and Operaon Manual
Safety
2
• 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.
• 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 qualied installer, service agency or the gas supplier.
• The warning signs in this manual are here to prevent injury to you and others. Please follow them explicitly.
WARNING
Indicates an imminently hazardous
situaon which, if not avoided, will
result in personal injury or death.
Indicates a potenally hazardous
situaon which, if not avoided,
could result in personal injury or
death.
Indicates a potenally hazardous
situaon which, if not avoided,
could result in minor or moder-
ate injury. It may also be used to
alert against unsafe pracces.
Safety alert symbol. Alerts you to potenal
hazards that can kill or hurt you and others.
DANGER CAUTION
WARNING
This manual contains the following important safety symbols. Always read and obey all safety messages.
Safety Symbols

Rinnai Commercial Hybrid System Installaon and Operaon Manual 5
• 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 control valve.
 Turn o the incoming water supply.
 Use only your hand to turn the manual gas control
valve. Never use tools. If the manual gas control
valve will not turn by hand, do not try to repair it;
call a trained and qualied 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 manual gas control valve
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.
• Only trained and qualied professionals are permied
to adjust parameter sengs.
• Do not use an extension cord or 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.
• Flammable liquids such as cleaning solvents, aerosols,
paint thinners, adhesives, gasoline and propane must
be handled and stored with extreme care. These
ammable liquids emit ammable vapors and when
exposed to an ignion source can result in a re
hazard or explosion. Flammable liquids should not be
used or stored in the vicinity of this or any other gas
appliance.
• DO NOT operate the water heater without the front
panel installed. The front panel should only be
removed for service/maintenance or replacing internal
components.
• BURN HAZARD. Hot exhaust and vent may cause
serious burns. Keep away from the water heater. Keep
small children and animals away from the water
heater.
• Hot water outlet pipes leaving the water heater can be
hot to touch.
• Do not store or use gasoline or other ammable
vapors and liquids in the vicinity of this or any other
appliance.
• Install the vent system per local and naonal codes.
• Do not install this water heater above 10,200 
(3,109 m).
• Do not obstruct combuson air to the water heater.
• Failure to properly vent this appliance can result in
death, personal injury and/or property damage.
• Rinnai recommends that every home have a carbon
monoxide (CO) alarm in the hallway near bedrooms in
each sleeping area. Check baeries monthly and
replace them annually.
• California law requires the following Proposion 65
warning to be provided:
For proper installaon, operaon and safety, it is important to follow the instrucons and adhere to the safety
precauons shown throughout this manual. The following precauons apply to the installer and consumer.
WARNING
DO NOT adjust the internal gas valve. The design is such that adjustment is not
required. Warranty will be voided if the internal gas valve is adjusted.
This product can expose you to chemicals including
lead, lead compounds and carbon bisulde which
are known to the State of California to cause cancer,
birth defects or other reproducve harm. For more
informaon, visit www.P65Warnings.ca.gov.
WARNING
Safety Precauons

6Rinnai Commercial Hybrid System Installaon and Operaon Manual
Model CHS199100CU
Appliance Type Commercial Hybrid Water Heang System Consisng of Condensing Tankless
Water Heater, Insulated Storage Tank, Pump and Controller
Installaon Type Internal (Indoor) Commercial Applicaons
Category Category IV
Ignion System Direct Electronic Ignion
Product Weight 431 lb (195 kg)
Gas Consumpon Btu/h (kW/h) Minimum: 15,000 (4.3) Maximum: 199,000 (58.3)
Water Supply Pressure 150 PSI (Maximum)
Temperature Seng 98° F (37° C) to 185° F (85° C)
Tank Volume 119 Gallons (450 Liters)
First Hour Delivery* 317 Gallons (1,200 Liters)
Sound Level 49 dB
Electrical Data
Normal 265 W
Standby 44 W
Freeze Protecon 148 W
Max Current 5.5 A
Fuse Tankless Water Heater Engine: 10 Amps, Controller: 10 Amps
Gas Supply Pressure** Natural 3.5 - 10.5 in. w.c.
Propane 8.0 - 13.5 in. w.c.
By-Pass Flow Control Electronic
Connecons Gas Supply Inlet: 3/4 in. MNPT Hot Water Outlet: 1-1/2 in. MNPT
Cold Water Inlet: 1-1/2 in. MNPT
Electric Connecons Appliance: AC 120 Volts, 60Hz.
Integrated Temperature Controller: DC 12 Volts (Digital)
Water Temperature Control Simulaon Feed Forward and Feedback
Commercial Energy Star Cered (CU199i) Yes
Complies with South Coast Air Quality
Management District 14 ng/J or 20 ppm NOx
Emission Levels (CU199i)
Yes
Product
Number
Gas
Type
Input Thermal
Eciency
U.S. Gallon / HR Liters / HR at Temperature Rise Indicated
Tank
Capacity
°F 30°F 40°F 50°F 60°F 70°F 80°F 90° 100°F 110°F 120°F 130°F 140°F
BTU/HR kW °C 17°C 22°C 28°C 33°C 39°C 44°C 50°C 56°C 61°C 67°C 72°C 78°C
CHS199100CU NG/
LP 199,000 58 97%
119 U.S.
Gals. GPH 780 585 468 390 334 292 260 234 213 195 180 167
450 LPH 2,953 2,214 1771 1476 1264 1105 984 886 806 738 681 632
Recovery Capabilies
Specicaons
* First Hour Delivery Rang is a theorecal calculaon based on 70% usable tank capacity (Tank Capacity x .70 + (recovery) = First Hour Rang
** The maximum gas supply pressure must not exceed the value specied by the manufacturer.
Rinnai products are connually being updated and improved; therefore, specicaons are subject to change without prior noce.
About
3

Rinnai Commercial Hybrid System Installaon and Operaon Manual 7
Dimensions and Connecons
RIGHT
TOP FRONT
LEFT
Measurements in inches (in.)

8Rinnai Commercial Hybrid System Installaon and Operaon Manual
Installation
4
THIS SECTION IS INTENDED FOR THE INSTALLER
Installer qualicaons: A trained and qualied professional must install the appliance, inspect it, and leak test the
Demand Duo™ before use. The warranty will be voided due to any improper installaon. The trained and qualied
professional 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; and training in installaon of
tankless water heaters. Training for Rinnai Tankless Water Heaters is accessible online at www.trainingevents.rinnai.us.
• This water heater is suitable for combinaon water
heang and space heang and not suitable for space
heang applicaons only.
• 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.
• 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 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.). For system tesng at pressures less than or
equal to 1/2 psi (3.5 kPa) (13.84 in W.C.) the
appliance must be isolated from the gas supply
piping by closing its individual manual shuto valve.
• You must follow the installaon instrucons and
those in the venng secon for adequate
combuson air 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.
• Combuson air must be free of chemicals, such as
chlorine or bleach, that produce fumes. These fumes
can damage components and reduce the life of your
appliance.
When installing the Demand Duo™, follow these guidelines:
DO NOT install the Demand Duo™ Commercial
Hybrid Water Heang System outdoors.
DO NOT install the water heater 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
required that a suitable drain pan, adequately
drained, be installed under the water heater.
The pan must not restrict combuson air ow.
DO NOT install the water heater in an area with
negave air pressure.
DO NOT obstruct the ow of combuson and
venlaon air.
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.
DO NOT
Installaon Guidelines

Rinnai Commercial Hybrid System Installaon and Operaon Manual 9
AHot Water Outlet *
BHot Water Outlet Valve *
CCold and Hot Unions *
DTemperature-Pressure Relief
Valve
EOperaon Unit / Temperature
Control
FTemperature-Pressure Relief
Valve Discharge Pipe
(do not cap, plug, or reduce )
*
GPressure Relief Valve Discharge
Pipe (do not cap, plug, or reduce ) *
HCondensate Discharge Pipe (Must
include air gap ) *
IDrain Pan *
JVent pipe (PVC Room Air shown
for illustraon purposes, see
venng secon for other opons)
*
KGas Control Valve *
LGas Union *
MDrip Leg (Sediment Trap) *
NCold Water Supply Valve *
OCold Water Supply *
PThermal Expansion Tank *
QNon-Tempered Supply Line *
RThermostac Mixing Valve *
SNon-Tempered Return Line *
* Field Supplied
Mixing Valve Installaon
Cold Water
Supply
Hot
Water
COLD
WATER
SUPPLY
ABC
D
O
N
P
J
E
I
FM
L
K
R
Q
S
GHD
HOT WATER
OUTLET
Typical Installaon Illustraons

10 Rinnai Commercial Hybrid System Installaon and Operaon Manual
Carefully unpack your system package and verify the
following contents are included.
If any items are damaged or missing, contact your local
dealer/distributor or call Rinnai Customer Care at
1-800-621-9419. Do not aempt to use any item that
appears damaged.
Items included with system:
• Rinnai Demand Duo™ Commercial Hybrid
Water Heang System
• Temperature and Pressure Relief Valve (Tank)
• Pressure Relief Valve (pre-installed on the
tankless water heater)
• Installaon and Operaon Manual (this manual)
• 2" PVC Vent Screens (x2) and Vent Screen
Screws
To avoid danger of suocaon, keep plasc bags
away from babies, small children and pets. Do not
use these bags in cribs, beds, carriages, or playpens.
The bags are not a toy.
WARNING
Gather the recommended tools and parts before
starng installaon.
Items Needed (Not Included)
• Pipe wrenches (x2)
• Phillips Head screwdriver
• Adjustable pliers
• Wire cuers
• Gloves
• Safety glasses
• Level
• Soap or gas leak detector soluon
• Approved venng
• Teon tape (recommended) or pipe
compound
• Pipe insulaon
Other Items You May Need
• 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
• Heat tape
• 5/8 in. ID PVC exible tubing
• Electrical wire
• Concrete wall anchors
• Oponal pipe cover
• PVC glue/cement and primer
• 2 conductor 22 AWG wire for controller
• Single gang electrical box
• Wire nuts
• Unions and drain valves
• Drain pan
• Earthquake strap
Items Included What You’ll Need
Unpack the Demand Duo™

Rinnai Commercial Hybrid System Installaon and Operaon Manual 11
Contaminant Maximum Level
Total Hardness Up to 200 mg/L
Aluminum * Up to 0.2 mg/L
Chlorides * Up to 250 mg/LL
Copper * Up to 1.0 mg/L
Dissolved Carbon Dioxide (CO2) Up to 15.0 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 mg/L
When selecng an installaon locaon, 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 in this manual.
Environment
* Source: Part 143 Naonal Secondary Drinking Water Regulaons
This secon provides informaon on the importance of water quality to the Rinnai Tankless Water Heater. The
informaon is intended to serve as general guidelines only and is not a complete list of water quality guidelines.
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 external (outdoor) models be used for these locaons where possible. In
applicaons ulizing room air where there are high levels of parculates, Rinnai oers a room air screen.
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 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 a more frequent ushing schedule.
This water heater includes a service indicator (Service Soon, SS). When selected in the parameter sengs, an SS code
will display on the controller indicang that it is me to ush and service the water heater. Scale build-up is caused by
hard water and can be accelerated if the water heater is 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.
Choose an Installaon Locaon
Water Quality Guidelines
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 contaminants. It is up to the installer to ensure the water does not con-
tain corrosive chemicals or elements that can aect or damage the Rinnai Tankless Water Heater. Water that contains
chemicals exceeding the levels below can damage the Rinnai Tankless Water Heater. Replacement of components due
to water quality damage is not covered by the warranty.

12 Rinnai Commercial Hybrid System Installaon and Operaon Manual
CLEARANCES
Locaon Clearance
Top 2 in. (51 mm)
(0 in. from vent components)
** Clearance for servicing the anode rods is 54 in. from the top of
the water heater
Boom (Ground) 0 in.
Front 6 in. (152 mm)
* Clearance for servicing is 24 in. (610 mm) in front of water heater
Back 0 in.
Sides (Le and Right) 0 in.
Door
0” Minimum 0” Minimum
0” Minimum ** 12” Minimum
*6” Minimum

Rinnai Commercial Hybrid System Installaon and Operaon Manual 13
• Choose the right hand truck to support the weight
and size of the water heater. Refer to the
Specicaons secon in this manual for specic
weights and dimensions.
• Use proper liing techniques to load the water
heater onto the hand truck:
 Posion the water heater onto the hand truck
so the weight is evenly balanced and the tank is
touching the rails of the hand truck.
 Secure the water heater to the hand truck:
 Posion STRAP A around the tankless unit
as illustrated below.
 Posion STRAP B around the base of the
tank below the lower enclosure.
Earthquake Strapping
Instrucons
1. Loosen the screws along the perimeter of the plasc
enclosures.
2. Remove the plasc enclosures.
3. Posion straps around the tank per the requirements
of California Oce of the State Architect. DO NOT
POSITION THE STRAPS OVER PIPE, FITTINGS or
WIRE.
4. Replace the plasc enclosures. Modicaon of the
plasc enclosures may be necessary to t the
enclosures over the earthquake straps.
5. Replace the screws around the perimeter of the
plasc enclosures.
Transporng the
Demand Duo™
Lower
Enclosure
Strap A
Strap B
Products installed in the state of California must be
braced, anchored, or otherwise secured to avoid
moon or falling during an earthquake. Contact the
California Oce of the State Architect located at 1102
Q Street, Suite 5100, Sacramento, CA 95811 for
instrucons.
NOTICE
STRAP
Plasc
Enclosure
(Side)
Plasc
Enclosure
(Boom)
STRAP

14 Rinnai Commercial Hybrid System Installaon and Operaon Manual
□ The water heater is not exposed to corrosive compounds in the air.
□ The water heater locaon complies with the required clearances.
□ The planned combuson air and exhaust terminaon locaons meet the required 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 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.
Use this checklist to ensure you have selected the correct locaon for the water heater.
Installaon Locaon Checklist

Rinnai Commercial Hybrid System Installaon and Operaon Manual 15
Venting
5
Venng Guidelines
• When installed as direct vent, the vent system
cered and listed with the appliance. You must use
vent components that are cered and listed with
the water heater model.
• 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.
• Engineered vent systems 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.
• 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.
• Refer to the instrucons of the vent system
manufacturer for component assembly instrucons.
WARNING
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.
DO NOT reduce the vent diameter.
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 manufacturer’s water heater or appliance.
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.
NOTICE
For venng informaon not specied in this secon, refer to the Installaon and Operaon Manual for Commercial
CU199 Condensing Tankless Water Heaters (supplied with each tankless water heater). This manual includes complete
venng informaon, including approved vent manufacturers and terminaons.
NOTICE

16 Rinnai Commercial Hybrid System Installaon and Operaon Manual
1. Install the water heater.
2. Determine the terminaon method—horizontal or vercal, concentric, or twin pipes, etc.
3. Determine proper locaon for wall or roof penetraon for each terminaon.
4. Install terminaon assembly as described in this manual or in the vent manufacturer’s installaon instrucons.
5. Install air and vent piping from water heater to terminaon.
6. Slope horizontal exhaust run towards the water heater 1/4 in per foot. DO NOT slope combuson air pipe
towards water heater.
7. Install vent supports and brackets allowing for movement from expansion, or as per vent manufacturer’s
instrucons or local code requirements.
8. Install vent screen (supplied with water heater) on PVC combuson air and exhaust terminaon elbows as
illustrated below.
• Press vent screen inside of terminaon piece/elbow.
• Secure vent screen to the elbow with screw provided.
Check to determine whether local codes supersede the
following 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.
• You must install a vent terminaon at least 12 in
above the ground or ancipated snow level.
The vent for this appliance shall not terminate:
• Over public walkways.
• Near sot vents or crawl space vents or other area
where condensate or vapor could create a nuisance
or hazard or cause property damage.
• Where condensate or vapor could cause damage or
could be detrimental to the operaon of regulators
pressure relief valves, or other equipment.
Listed below are 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 part of
the terminaon.
Venng Installaon Sequence
Terminaon Consideraons

Rinnai Commercial Hybrid System Installaon and Operaon Manual 17
Three types of venng opons are available:
Concentric Pipe
Combuson air and exhaust vent directly through
a single concentric connecon. Hot exhaust exits
through the interior tube, while combuson air
Exhaust
Exhaust
Combuson
air
Combuson
air Combuson
air
Combuson
air
Exhaust
Direct Vent Non-Direct (Room Air) Vent
Mulple water heaters sharing a combuson air
header and a separate exhaust header that vents di-
rectly through separate penetraons to the outside.
Combuson Air
Exhaust Exhaust
Room Air
For Combuson
Twin Pipe
Combuson air and exhaust vent directly
Room air is used for combuson while exhaust
vents to the outside.
Mulple water heaters using room air for
combuson while sharing an exhaust header that
vents directly to the outside.
Direct Vent (Concentric Pipe and Twin Pipe)
1
Non-Direct Vent (Room Air)
2
Common Vent (Indoor Units Only. Direct Vent and Non-Direct/Room Air Vent)
3
Select a Vent Type

18 Rinnai Commercial Hybrid System Installaon and Operaon Manual
Canadian Installaons
(CSA B149.1)
U.S. Installaons
(ANSI Z223.1 /NFPA 54)
Ref Descripon Direct Vent (Indoor Unit) Direct Vent (Indoor Unit)
AClearance above grade, veranda, porch, deck, or balcony 12 in. (30 cm) 12 in. (30 cm)
BClearance to window or door that may be opened 36 in. (91 cm) 12 in. (30 cm)
CClearance to permanently closed window **
DVercal clearance to venlated sot, located above the terminal within a
horizontal distance of 2  (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 **
IClearance to service regulator vent outlet
Above a regulator within 3 
(91 cm) horizontally of the vercal
center line of the regulator vent
outlet to a maximum vercal
distance of 15  (4 m)
*
JClearance to non-mechanical air supply inlet to building or the
combuson air inlet to any other appliance 36 in. (91 cm) 12 in. (30 cm)
KClearance to a mechanical air supply inlet 6  (1.83 m) 3  (91 cm) above if within
10  (3 m) horizontally
LClearance above paved sidewalk or paved driveway located on public
property 7  (2.13 m) [1] *
MClearance under veranda, porch, deck, or balcony 12 in. (30 cm) [2] *
Direct Vent Terminaon Clearances (For Concentric and Twin Pipe)
Direct Vent (Concentric Pipe and Twin Pipe)
1
AIR SUPPLY INLET
VENT TERMINAL
AREA WHERE TERMINAL
IS NOT PERMITTTED
X
V
SNOW
TERMINATION
Clearance in
Ref. A also
applies to
anticipated
snow line
Clearance to opposite wall is 24 in. (60 cm).
[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 mini-
mum of two sides beneath the oor.
 Clearances are in accordance with local installaon codes and the
requirements of the gas supplier. (Dégagement conforme aux codes
d’installaon locaux et aux exigences du foumisseur de gaz.)

Rinnai Commercial Hybrid System Installaon and Operaon Manual 19
All terminaons (horizontal and/or vercal) must terminate 12 in. (0.30 m) above grade or ancipated snow level.
12 in. (0.30 m)
Between terminals at same level
60 in. (1.52 m)
Between terminals at dierent levels
Note: 24 in. (0.61 m)
to wall or parapet
Combuson air and exhaust vent directly through a single
concentric connecon. Hot exhaust exits through the interior
tube, while combuson air enters through the outer layer.
Combuson
air
Exhaust
Concentric Pipe Terminaon Clearances
Direct Vent (Concentric Pipe)
1
Concentric Pipe Overview
Combuson
air
Inside
Corner
12 in.
(0.30 m)
12 in.
(0.30 m)
60 in. (1.52 m) vercal-
ly between terminals

20 Rinnai Commercial Hybrid System Installaon and Operaon Manual
Remove and discard screw from
concentric ue connecon.
Remove exhaust adapter ring (discard for
concentric venng conguraons).
Concentric
Install the concentric vent. Ensure it
is properly seated.
Secure the vent pipe to the concentric ue
connecon with the supplied screw.
Concentric Pipe Installaon Instrucons
Important: Install the venng terminaon according to the diagrams and instrucons in
this manual. Slope the venting 1/4 in. per foot toward the appliance according to the vent
manufacturer’s installation instructions. Dispose of condensate per local codes.
Direct Vent (Concentric Pipe)
1
2
3
1
4
Concentric Vent Maximum Equivalent Length
Vent Sizes 2 in. X 4 in. 3 in. X 5 in.
Vent Lengths 65  (20 m) 150  (46 m)
• 45° elbow is equivalent to 3  (1 m)
• 90° elbow is equivalent to 6  (2 m)
Concentric Pipe Example Vent Applicaons
Horizontal Wall Terminaons
2 in. x 4 in.
3 in. x 5 in.
Vercal Roof
2 in. x 4 in.
and
3 in. x 5 in.
Concentric Pipe Maximum Vent Length