Rinnai RCB301AN User manual

2 Rinnai Commercial Boiler Installation and Operation Manual
Copyright 2023 Rinnai America Corporaon. Rinnai® is a registered trademark of Rinnai Corporaon
used under license by Rinnai America Corporaon. Rinnai America Corporaon connually updates
materials, and as such, content is subject to change without noce.
If the informaon in these instrucons is not followed exactly, a re or explosion may result
causing property damage, personal injury or loss of life.
• 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.
WARNING

Rinnai Commercial Boiler Installation and Operation Manual 3
1. Welcome ................................................................................................................................................ 4
1.1 To The Consumer......................................................................................................................... 4
1.2 To The Installer............................................................................................................................ 4
1.3 Acronyms and Abbreviaons ....................................................................................................... 4
2. Safety ..................................................................................................................................................... 5
2.1 Safety Symbols ............................................................................................................................ 5
2.2 Safety Precauons........................................................................................................................ 5
3. About the Boiler..................................................................................................................................... 7
3.1 Front View................................................................................................................................... 7
3.2 Boom View................................................................................................................................ 7
3.3 Components................................................................................................................................ 8
3.4 Altude ..................................................................................................................................... 11
3.5 Specicaons............................................................................................................................. 12
3.6 Dimensions................................................................................................................................ 13
3.7 Included Accessories.................................................................................................................. 15
3.8 Oponal Accessories.................................................................................................................. 16
4. Installaon ........................................................................................................................................... 18
4.1 Installaon Guidelines ............................................................................................................... 18
4.2 What You Will Need .................................................................................................................. 19
4.3 Choose an Installaon Locaon ................................................................................................. 20
4.4 Mount the Boiler to the Wall ..................................................................................................... 23
4.5 Fill the Condensate Collector..................................................................................................... 23
5. Venng................................................................................................................................................. 24
5.1 Guidelines ................................................................................................................................. 24
5.2 Venng Installaon Sequence ................................................................................................... 25
5.3 Terminaon Consideraons....................................................................................................... 25
5.4 PVC Venng Safety Switch......................................................................................................... 26
5.5 Venng Opons.......................................................................................................................... 27
6. Gas Supply............................................................................................................................................ 47
6.1 Connect the Gas Supply............................................................................................................. 47
6.2 Gas Operang Instrucons ........................................................................................................ 48
6.3 Gas Pipe Sizing Reference Tables ............................................................................................... 49
7. CH System Piping.................................................................................................................................. 52
7.1 Guidelines ................................................................................................................................. 52
7.2 Instrucons ............................................................................................................................... 52
7.3 Common CH Components.......................................................................................................... 53
7.4 Hydraulic Separaon ................................................................................................................. 58
7.5 Connect the Pressure Relief Valves............................................................................................ 60
7.6 Connect the Condensate Drain Line........................................................................................... 61
8. DHW System Piping with Indirect Tank................................................................................................ 62
8.1 Guidelines ................................................................................................................................. 62
8.2 Indirect Tank Control Opons.................................................................................................... 62
9. Power Supply ...................................................................................................................................... 66
9.1 Guidelines ................................................................................................................................. 66
9.2 Electrical Connecons................................................................................................................ 67
9.3 Post-Power Supply Connecon Checklist ................................................................................... 70
10. Commissioning................................................................................................................................... 71
10.1 Safety Precauons ................................................................................................................... 71
10.2 Filling Process .......................................................................................................................... 71
10.3 Deaeraon Process.................................................................................................................. 72
11. Post-Installaon Checklist.................................................................................................................. 73
12. Operaon ........................................................................................................................................... 75
12.1 Start-Up Informaon ............................................................................................................... 75
12.2 Control Panel........................................................................................................................... 76
12.3 Error and Diagnosc Codes...................................................................................................... 98
12.4 Perform Combuson Analysis................................................................................................105
12.5 Operang Informaon........................................................................................................... 107
13. Maintenance .................................................................................................................................... 111
13.1 Owner Maintenance............................................................................................................... 111
13.2 Licensed Professional Maintenance ....................................................................................... 112
13.3 Service of Heat Exchanger ..................................................................................................... 115
13.4 Instrucons to Clean Condensate Trap .................................................................................. 117
13.5 Test the Ignion Safety Shut O Device ................................................................................. 118
14. Appendices....................................................................................................................................... 119
14.1 Flush the CH Plumbing System...............................................................................................119
14.2 Ladder Diagram ..................................................................................................................... 123
14.3 Wi-Fi Connecvity.................................................................................................................. 124
14.4 Building Management System (BMS)..................................................................................... 125
14.5 Remove a Boiler from a Common Vent System...................................................................... 128
14.6 Massachuses State Gas Regulaons .................................................................................... 129
14.7 Warranty ...............................................................................................................................130

4 Rinnai Commercial Boiler Installation and Operation Manual
Thank you for purchasing a Rinnai Condensing
Boiler. Before installing and operang this
boiler, be sure to read these instrucons
completely and carefully to familiarize
yourself with the boiler’s features and
funconality.
ANSI American Naonal Standards
Instute
Btu Brish Thermal Unit
CH Central Heang
SOLO Heang only boiler capable of
DHW through an indirect tank
DHW Domesc Hot Water
GPM Gallons per minute
LP Liquid Propane
LWCO Low Water Cut O
NG Natural Gas
PP Polypropylene
PRV Pressure Relief Valve
PSI Pounds per square inch
wc Inches water column
• A trained and qualied professional must
install the boiler, 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 condensing
boilers. Training on Rinnai
Condensing Boilers is accessible at:
rinnaipro.myabsorb.com.
Following is a list of common acronyms and
abbreviaons used in this manual:
• You must read the enre manual to
properly operate the boiler.
• Keep this manual for future reference.
• As when using any appliance generang
heat, there are certain safety precauons
you should follow. See secon “2.2 Safety
Precauons” for detailed safety
precauons.
• Be sure your boiler is installed by a
licensed installer.
• If installing in the state of Massachuses,
read secon “14.6 Massachuses State
Gas Regulaons” in this manual.
• Read all instrucons in this manual before
installing the boiler. The boiler must be
installed according to the exact
instrucons in this manual.
• Proper installaon is the responsibility of
the installer.
• When installaon is complete, leave this
manual with the boiler or give the manual
directly to the consumer.
Table: Acronyms and Abbreviaons

Rinnai Commercial Boiler Installation and Operation Manual 5
Safety alert 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 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 moderate injury. It may also be used to
alert against unsafe pracces.
This manual contains the following important
safety symbols. Always read and obey all
safety messages.
The following precauons apply to the
installer and consumer. Read and follow all
instrucons in this secon.
• 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.
• Do not store or use gasoline or other
ammable vapors and liquids in the
vicinity of this or any other appliance.
• 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.
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
DANGER
WARNING
CAUTION

6 Rinnai Commercial Boiler Installation and Operation Manual
• 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 boiler 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
boiler. Keep small children and animals
away from the boiler.
• Heang supply and return pipes leaving
the boiler can be hot to touch.
• Install the vent system per local and
naonal codes.
• Do not install this boiler above 10,200 
(3,109 m).
• Do not obstruct combuson air to the
boiler.
• This product burns gas to produce heat.
The appliance must be properly installed,
operated, and maintained to avoid
exposure to appreciable levels of carbon
monoxide and the installer is required to
conrm that at least one carbon monoxide
alarm is installed in the living space before
the appliance is put into operaon. It is
important for the carbon monoxide alarms
to be installed, maintained, and replaced
following the alarm manufacturer’s
instrucon and applicable local codes.
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.
• Do not use this appliance if any part has
been under water. Immediately call a
licensed professional to inspect the
appliance and 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.
• It is strongly recommended that you use a
trained and qualied professional who has
aended a Rinnai installaon training class
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.
• To protect yourself from harm, before
performing maintenance:
− Turn o the electrical power supply by
turning o the electricity at the circuit
breaker. (The boiler controller does
not control the electrical power.)
− Turn o the gas at the gas control,
usually located immediately below the
boiler.
− Turn o the incoming water supply.
Turning o the water for the central
heang system is done at the boiler
system lling staon shut-o valve or
the main water supply to the building.
− 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.
• Proper venng is required for the safe
operaon of this appliance. Failure to
properly vent this appliance can result in
death, personal injury and/or property
damage.

Rinnai Commercial Boiler Installation and Operation Manual 7
The Rinnai Commercial Boiler is a wall-
mounted, gas-fired boiler designed to
provide heating to the building with the
ability to connect an indirect tank for
DHW production.
Topics in this section
• Front View
• Bottom View
• Components
• Altitude
• Specifications
• Dimensions
• Included Accessories
• Optional Accessories
Central
Heating
Supply
Gas
Central Heating
Return
Condensate
Drain
Wi-Fi
Module Reset
Button
Vent
Connections
Piping
Connections
Controller
Figure 2
Figure 1

8 Rinnai Commercial Boiler Installation and Operation Manual
Le Side Internal -
RCB301AN shown
Flue Thermistor
Automac Air Vent
Return Thermistor
Spark Generator
Water Pressure Sensor
Ignion Electrode
Supply Thermistor
Supply Water Pipe
Fan
Flue Pressure
Switch
High Voltage Terminal Strip
Burner Door
Switch
Main Control
Check Valve
7-Inch Touch
Screen Display
Gas Valve
Power Switch
Exhaust
Intake
Flame Rod
(Ionizaon Probe)
16
17
15
12
13
14
11
8
9
10
7
4
5
6
3
2
1
Refer to the next page for a descripon of each component.
Figure 3
Right Side Internal
(Main Control Hidden) -
RCB301AN shown
Thermal Fuse
Heat Exchanger
Return Water Pipe
Condensate Trap
Gas Valve with
Throle Screw
Air/Gas Mixer
Low Voltage
Terminal Strip Cascade Module
25
20
21
22
19
23
24
18
Figure 4

Rinnai Commercial Boiler Installation and Operation Manual 9
Listed below are descripons of each boiler component. Refer to the previous page for component
illustraon.
Item Name Descripon
Return Thermistor A sensor that monitors the water temperature returning into the
boiler.
Automac Air Vent A device used to bleed the air from the heang system.
Spark Generator Applies high voltage through the spark electrode to ignite the
burner.
Water Pressure Sensor A sensor that monitors the pressure in the system and will
disable operaon in case it senses low or high water pressure.
Supply Thermistor A sensor that monitors the boiler outlet water temperature. The control will shut down the boiler in case the temperature exceeds
a certain limit.
Ignion Electrode Provides direct spark to ignite the burner.
Supply Water Pipe A 1-1/4 in. water pipe that supplies hot water from the heat
exchanger to the system.
Fan
Pulls air and gas through the air/gas mixer. Air and gas are pre-
mixed inside of the fan and are pushed into the burner for
combuson.
High Voltage Terminal
Strip Contains connecon points for main power supply and all pumps power.
Flue Pressure Switch A safety device that monitors the pressure in the vent and shuts down the appliance in case of blockage to avoid unsafe
condions.
Flue Thermistor A sensor that monitors the ue gas exit temperature. The control will shut down the boiler if the ue gas temperature gets too hot
to protect the ue pipe from overheang.
Burner Door Switch A switch that will break the control circuit, shung down the
boiler in case the burner door temperature is too high.
Main Control
The integrated controller monitors and controls the system
operaon. The controller responds to internal and external
signals and controls the fan, gas valve, spark generator, and
pumps to meet the heat demand.
Flame Rod (Ionizaon
Probe) Detects and monitors the presence of a ame.
Check Valve
Prevents ue gas back ow into the fan in case of negave
pressure in the boiler room in a power vent installaon. The
check valve also acts as back ow preventer in a common vent
system where mulple units are cascaded.
7-Inch Touch Screen
Display The full-color touch screen allows a user friendly interface with the boiler control.
Gas Valve Power Switch Manually interrupts the power to the gas valve.
Air/Gas Mixer The venturi controls the mixture of air and gas before entering
the burner for combuson.
Low Voltage Terminal Contains connecon points for low voltage input and output
19
16
17
18
15
12
13
14
11
8
9
10
7
4
5
6
3
2
1
Table: Boiler Component Descripons

10 Rinnai Commercial Boiler Installation and Operation Manual
25
20
21
22
23
24
Item Name Descripon
Thermal Fuse A safety device that will stop the boiler operaon in case of unusual
temperature rise.
Heat Exchanger The stainless steel condensing heat exchanger is eciently designed to maximize heat transfer through the coils while providing protecon
against ue gas corrosion.
Return Water Pipe A 1-1/4 in. water pipe that returns water from the system to the heat
exchanger to be reheated.
Condensate Trap
The high eciency heat exchange produces condensate during
operaon. The condensate trap manages the condensate disposal and
the built-in oat prevents ue gases to escape through the condensate
drain.
Gas Valve The zero governor gas valve regulates the gas ow through the venturi
based on sucon from the fan.
Cascade Module Used to establish communicaon between boiler in a cascade system
by connecng them to each other using two conductor 18-20 AWG
shielded wire.
Webserver Card/
Wi-Fi Module
The Webserver Card/Wi-Fi Module (located on boom of boiler)
(Figure 5) allows the installer to remotely monitor the system
operaon, pro-acvely opmize eciency, and aid in troubleshoong.
This card also establishes the communicaon between main control
board and user interface screen.
Boiler Name Plate The ASME name plate (Figure 5) includes the Naonal Board (NB) and
Canadian Registraon Number (CRN) numbers.
Addional Components Not Shown in Images:
Burner The metal ber and stainless steel burner uses premixed air and gas
to provide a wide range of ring rates.
Outdoor Sensor Uses the outdoor temperature to adjust the unit setpoint to provide
greater eciency.
Cascade System
Sensor In a cascade system, the master boiler requires a system supply sensor to operate properly. The locaon of the sensor should be downstream
of the of the boiler connecon in the main system loop.
DHW Sensor/
Aquastat Monitors and controls the temperature of an indirect tank.
26
Webserver Card/
Wi-Fi Module
26
Boom View
Boiler Component Descripons (Connued)
Figure 5
27
27
Boiler
Name
Plate

Rinnai Commercial Boiler Installation and Operation Manual 11
This boiler can operate from sea level up to 10,200 feet [3,109 m]. The table below represents the
de-rates for each model, gas type, and altude. For proper operaon ensure to set the control for
proper gas type and altude. Use the setup, boiler setup page on the boiler screen for proper gas
type and altude sengs. De-rate values are based on proper combuson sengs as
recommended in this manual. For installaon above 2,000  (609 m) in Canada, follow all
applicable local codes and regulaons.
NOTE: See control secon on how to change altude seng from the control panel.
ALTITUDE VENTING:
For all installaons above 2000  (609 m), the venng is reduced from 140 feet to 90 feet.
Air Intake: 90 Feet
Exhaust: 90 Feet
0 - 2000  2001 - 5400  5401 - 7700  7701 - 10200 
Model
NG LP NG LP NG LP NG LP
RCB301AN 0.0 % 0.0 % 0.0 % 0.0 % 5.0 % 13.0 % 15.0 % 24.0 %
RCB399AN 0.0 % 0.0 % 7.0 % 7.0% 16.0 % 20.0 % 23.0 % 27.0 %
NOTE: The values listed on the above table are the total percentage of boiler input de-rate for each
elevaon range.

12 Rinnai Commercial Boiler Installation and Operation Manual
1Maximum 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.
Table: Specicaons
Model RCB301AN RCB399AN
Appliance Type Condensing Wall-Mounted, Gas-Fired, Heat-Only (Solo) Boiler
Installaon Type Internal (Indoor) Commercial Applicaons
Model Numbers RCB301AN, RCB399AN
Ignion System Direct Electronic Ignion
Gas Types
Natural and Propane
IMPORTANT: Units ship as NG only. Propane Conversion Kits
available as accessory (purchased separately)
Dimensions - w, h, d 19.4 in. x 35.75 in. x 21.8 in. (493 mm x 908 mm x 554 mm)
Weight (Shipping) 194 lb (88 kg) 207lb (94 kg)
Weight (Appliance) 170 lb (77 kg) 183 lb (83 kg)
Heat Exchanger Surface Area 24.6 sq  30.7 sq 
Gas
Consumpon
(Btu/h)
Minimum 30,100 39,900
Maximum 301,000 399,000
Temperature
Seng CH (Minimum - Maximum) 86°F - 180°F (30°C - 82°C)
Indirect Tank
(DHW) 104°F - 176°F (40°C - 80°C)
Water Content 1.8 gal (6.8 lt) 2.2 gal (8.3 lt)
Water Pressure CH Minimum: 14.5 PSI (1 bar) Maximum: 87 PSI (6 bar)
Maximum Allowable Water Pressure (MAWP): 160 PSI (1103 kPa)
PRV 75 PSI (5.2 bar) (Pressure Relieve Valve included with system)
Sound Level 55 dB(A) 56 dB(A)
Electrical Data Normal 133 W 210 W
Standby 10 W
Max Current 6.3 Amps
Fuse 2 x 6.3 Amps
Gas
Supply Pressure1Natural Gas 3.5 in. - 10.5 in. wc (0.87 - 2.61 kPa)
Propane 8.0 in. - 13.5 in. wc (1.99 - 3.36 kPa)
Electric Connecons AC 120 Volts, 60 Hz
Cercaons ANSI Z21.13, CSA 4.9, ASME
Canada CRN Y6325.2C
Warranty Heat Exchanger: 10 Years. All Other Parts & Components: 1 Year.
Reasonable Labor: 1 Year. See the “Rinnai Commercial Boiler
Warranty” for Complete Details
Opons: • Direct Vent
• Non-Direct Vent (Room Air)
Venng
45° elbow is
equivalent to 3 
(1 m).
90° elbow is
equivalent to 6 
(2 m).
Materials PVC, CPVC, PP and Stainless Steel
Vent Size 4 in. PVC/CPVC
Exhaust Vent Run (Min-Max): 10  (3 m) - 140  (43 m)
Intake Vent Run (Min-Max): 0  (0 m) - 140  (43 m)
High Altude • 0-2,000 feet (0-609 m) - 140  (43 m)
• For altudes above 2,000  (609 m), vent length is reduced to 90
 (27 m).

Rinnai Commercial Boiler Installation and Operation Manual 13
Measurements: in. [mm]
Figure 6 Boom view shown
on next page.

14 Rinnai Commercial Boiler Installation and Operation Manual
Measurements: in. [mm]
Condensate Drain
Gas
Connection Connection Size Minimum Pipe Size
Gas 1 in. NPT 1 in.
CH In (CH Return) 1-1/4 in. NPT 1-1/4 in.
CH Out (CH Supply) 1-1/4 in. NPT 1-1/4 in.
Condensate Drain 1 in. NPT 3/4 in.
Venting (Intake & Exhaust) 4 in. PVC/CPVC 4 in.
Table: Connection Sizes
Figure 7
Dimension “A”:
Model RCB301AN:
10.96 [278]
Model RCB399AN:
13.84 [352]
Central Heating
Return
Central Heating
Supply

Rinnai Commercial Boiler Installation and Operation Manual 15
Carefully unpack your boiler system and verify the following contents are included. If any items are
damaged or missing, contact your local dealer/distributor. Do not aempt to use any item that
appears damaged.
• Installaon and Operaon Manual
(this manual)
• User Manual
• Warranty Card
• Addional technical literature in-
cluded inside product box
DOCUMENTATION
WALL MOUNTING BRACKET
(WITH SCREWS)
PART #: 809000198
PRESSURE RELIEF VALVE, 75 PSI
OUTDOOR TEMPERATURE
SENSOR
PART #: 805000097
PART #: 807000224
Figure 8
SPARE FUSES - 2 X 6.3 A
(LOCATED INSIDE OF MAIN
CONTROL COVER)
INTAKE PIPE SCREWS
4.8 X 25 MM SS PANHEAD PH2
(TAPPED TO INTAKE ADAPTER)
PART #: 803000079
PART #: 809000304

16 Rinnai Commercial Boiler Installation and Operation Manual
The following oponal accessories are available for the Rinnai Commercial Boiler.
Neutralizes the condensate
generated by the boiler.
CONDENSATE NEUTRALIZER
PART #: 804000074
Filters and eliminates debris (> 0.5 mm)
from entering the combuson chamber
for indirect venng (room air) piping.
AIR INLET FILTER
PART #: 803000050
In a cascade system the Master boiler
requires a system supply sensor in
order to operate properly. The locaon
of the sensor should be downstream of
the of the boiler connecon in the
main system loop.
CASCADE SYSTEM SENSOR
PART #: 803000051
Provides a standalone mounng
soluon for the Rinnai Commercial
Boiler.
BOILER RACK
PART #: 803000047
GAS CONVERSION KIT
Converts the boiler gas type.
PART #: 803000053 - 301 NG
PART #: 803000054 - 399 NG
PART #: 803000048 - 301 PROPANE
PART #: 803000049 - 399 PROPANE Connued on next page.

Rinnai Commercial Boiler Installation and Operation Manual 17
Oponal Accessories (Connued)
To establish boiler communicaon with
Building Management System (BMS)
through BACnet.
BACNET ADAPTER
PART #: 803000078
To establish boiler communicaon with
Building Management System (BMS)
through LonWorks.
BACNET ADAPTER WITH LONWORKS
PART #: 803000080

18 Rinnai Commercial Boiler Installation and Operation Manual
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 boiler 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 condensing boilers.
Topics in this secon
• Installaon Guidelines
• What You Will Need
• Choose an Installaon Locaon
• Mount the Boiler to the Wall
• Fill the Condensate Collector
• This boiler is cered for installaon in
residenal and commercial applicaons.
• This boiler is suitable for combinaon
water heang through an indirect tank
and central heang.
• 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 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 secon
“5. Venng” for adequate combuson
air and exhaust.
• 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.
• Where required by the authority having
jurisdicon, the installaon must comply
with the Standard for Controls and
Safety Devices for Automacally Fired
Boilers, ANSI/ASME CSD-1.

Rinnai Commercial Boiler Installation and Operation Manual 19
DO NOT install the boiler 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
boiler. The pan must not restrict
combuson air ow.
DO NOT install the boiler in an area
with negave air pressure.
DO NOT obstruct the ow of
combuson and venlaon air.
DO NOT use substute parts that
are not authorized for this boiler.
DO NOT install the boiler on
carpeng.
DO NOT install boiler outdoors.
DO NOT
Gather the recommended tools and parts
before starng installaon.
Items Needed
• Boiler Pump
• Pressure relief valve for domesc hot
water (150 PSI / 10.3 Bar)
(as necessary, if using a separate
indirect tank).
• Pressure/Temperature Gauge
Note: When aaching the pressure/
temperature gauge, please comply
with applicable codes and the ASME
standard.
• Low loss header or closely spaced tee
• Expansion tank for a closed heang
system
• Air separator
• Standard tools for central heang, gas
ng, plumbing and electrical wiring.
• Digital manometer
• Combuson analyzer (intended for use
with condensing boilers)
• Digital mulmeter capable of reading
microamps
• pH digital meter or test strips
• For wall mounng bracket installaon:
− Level
− Screws (use appropriate screws for
type of wall construcon)
Other Items You May Need
• Hand truck with fastening belt
• Ensure the wall is of sucient
strength to support the weight of the
boiler, piping and any other
components needed for installaon;
if it is not, please reinforce the wall as
appropriate.
• Operang limits of the boiler:
Maximum boiler set
point temperature:
180°F (82°C)
Maximum operang
pressure:
87 psi (6 bar)
Maximum allowable
working
temperature ASME:
210°F (99°C)
Maximum allowable
working pressure
ASME:
160 psi (11 bar)
Pressure Relief Valve
(shipped with unit):
75 psi (5.2 bar)

20 Rinnai Commercial Boiler Installation and Operation Manual
Consideraon of care for your boiler 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 contain corrosive chemicals or
elements that can aect or damage the
boiler.
• Water that contains chemicals exceeding
the levels below can damage the boiler.
• The pH level must fall between 6.5 and
8.5.
• Total water hardness must fall between 5
and 12 grains per gallon.
• When water hardness is higher than
12 grains per gallon consult local
water treatment companies.
• Chloride concentraon must be less than
150 ppm (mg/l)
• Do not ll appliance to work with
water containing chlorides in excess
of 150 ppm (mg/l).
• Using chlorinated fresh water should
be acceptable as levels are typically
less than 5 ppm (mg/L).
• Do not connect the appliance to
directly heat swimming pool or spa
water
• Total Dissolved Solids (TSD) must be
between 100 and 350 ppm (mg/l).
• Total dissolved solids are minerals,
salts, metals, and charged parcles
that are dissolved in water.
When choosing 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.
This secon provides informaon on the
importance of water quality to the Rinnai
Condensing Boiler. The informaon is
intended to serve as general guidelines only
and is not a complete list of water quality
guidelines.
• The greater the amounts of TDS
present, the higher the corrosion
potenal due to increased
conducvity in the water.
• If using soened water to ll the
appliance, it is sll possible to have
high TDS. This water can be
corrosive. Consult local water
treatment companies for other
treatment soluons to reduce this
aect.
• Unsuitable heang system water can
cause the formaon of scale or sludge,
which aects system eciency. It can
also cause corrosion and reduce life of
the heat exchanger. It is crical to
monitor pH, hardness level, chlorides,
and TDS to prolong the life of the
appliance.
• Never use water that has been treated by
a reverse osmosis, deionized, or dislled
water to soen the water to ll the
heang system.
• Connual fresh makeup water will
reduce the life of the appliance. The
addion of oxygen carried in by the make
up water can cause internal corrosion in
the system.
• When using a make up water, It is
recommended to install a water meter to
monitor the amount of water being
introduced into the system. The total
annual make up water should not exceed
5% of the total system water volume.
• Oxygen permeable or rubber tubing is
not permied in the heang system
unless it is separated from the boiler by a
plate heat exchanger.
• Thoroughly ush the system prior to
lling. While ushing, isolate the boiler.
• Do not introduce any system cleaner into
the boiler. Flush the system thoroughly
to remove all system cleaner before
lling the boiler with water.
• When freeze protecon of the heang
system is desired, use Rinnai-approved
anfreezes.