Rinnai I Series Service manual

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DHW Setpoint
Temperature (°F) 140° 135° 130° 125° 120° 115° 110° 108° 106° 104° 102° 100° 98°
Typical Pump OFF
Intervals (Minutes) 910 11 12 14 16 19 20 22 24 26 28 31
Home includes dedicated hot water
and cold water lines.
PURPOSE: To announce the I-Series Condensing Combi Boiler oers DHW recirculaon and to explain
how DHW recirculaon works, the dierent recirculaon modes, and how to congure the boiler for
DHW recirculaon.
I-Series Condensing Combi Boiler Models: i060C, i090C, and i120C
DHW Recirculaon Facts:
• Recirculaon circulates hot water through the plumbing system, so hot water is always available in
whatever part of the house that the consumer may need it.
• Recirculaon requires an external recirculaon pump. For pump sizing, reference the “DHW
Pressure Drop and Flow Curve” in the Boiler Installaon and Operaon Manual.
• An oponal 24V mer can be used to set the me intervals and duraon of recirculaon (an
example mer is the Intermac® MIL72ASTUZ-24).
• Two recirculaon modes are available: Dedicated and Crossover:
Dedicated Mode:
• The plumbing system includes a dedicated hot water
return line.
• Recirculaon technology in the boiler decides if the
pump will turn on based on me intervals and DHW
setpoint temperature.
• How the recirculaon pump works:
− The pump turns ON and runs unl the DHW
return water temperature is within 6°F of the
setpoint temperature, or for 20 minutes,
whichever occurs rst.
− The pump stays OFF based on the DHW setpoint
temperature (as outlined in the table below).
Note: Rinnai strongly recommends installing insulaon to the hot water and dedicated return lines
to decrease the amount of heat loss.
Hot water
Cold water
Technical Bullen 158 - I-Series Boiler with DHW Recirculaon

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Dedicated Mode Plumbing Diagram
DHW Recirculaon Pump
Recirculaon Pump Wiring
Timer
(Oponal)
Hot Water Supply Line
Gas Supply Line
Cold Water Supply Line
Expansion Tank
This diagram is not a complete
piping diagram; it shows DHW
piping only (Central Heang
piping is not displayed). Refer to
the Boiler Installaon and
Operaon Manual for a complete
piping diagram.
IMPORTANT
Hot Water Fixtures
Building Hot
Water Return Line

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Crossover Mode (Factory Default):
• The plumbing system does not have a dedicated
circulaon return line. Crossover mode requires
installaon of a thermal bypass valve at the
furthest xture in the plumbing system. When
installed, the boiler uses the cold water line for
hot water recirculaon. A thermal bypass valve
can be purchased through Rinnai (PN:
107000143) or plumbing supply stores.
• How the recirculaon pump works:
− The pump turns ON and runs unl the
thermal bypass valve closes (with a DHW
ow less than approximately 0.26 GPM),
or for 20 minutes, whichever occurs rst.
− The pump stays OFF for 10 minutes.
Note: The thermal bypass valve should only be
used for Crossover Mode recirculaon systems.
Do not install more than one thermal bypass
valve in the plumbing system.
Home includes a thermal bypass valve
installed at the furthest xture
Gas Supply Line
Expansion Tank
Cold Water Supply Line
Hot Water Supply Line
Recirculaon
Pump Wiring
Recirculaon
Pump
Timer
(Oponal)
Thermal Bypass Valve
installed at furthest xture
in plumbing system.
This diagram is not a complete
piping diagram; it shows DHW
piping only (Central Heang
piping is not displayed). Refer to
the Boiler Installaon and
Operaon Manual for a complete
piping diagram.
Crossover Mode Plumbing Diagram

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Parameter
Number Funcon/Descripon
Selecon
A
(Default) b
12 • Select opon A for Crossover Mode
• Select opon b for Dedicated Mode
Crossover
Mode
Dedicated
Mode
13 Yes
(Timer)
No
(No Timer)
• Select opon A if a mer is used to control DHW recirculaon
• Select opon b if a mer is not used to control DHW recirculaon
Congure the Boiler for DHW Recirculaon:
Note: Refer to the Boiler Installaon and Operaon Manual for complete DIP Switch and Parameter
Seng instrucons.
1. Remove the boiler’s front panel.
2. Locate the PC Board (lower le side of unit).
3. Locate the DIP switches on the PC Board (see below). Adjust DIP switch 3 to the ON posion.
DIP Switch 3
PC Board ON
4. Locate the Parameter Sengs buon on the PC Board (red buon). Press and hold the red
buon for ve seconds to enter into Parameter Sengs mode.
5. Adjust Parameters 12 and 13 to the desired sengs shown in the table below.
Parameter Sengs buon
Step 1: Set DIP Switches and Parameter Sengs

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Step 2: Connect Wiring to PC Board
6. Wire the external DHW recirculaon pump to the DHW_Pump Terminal connecon on the PC
Board (see A below).
7. If using a mer:
• Wire the 24V AC mer circuit to the 24V AC for External Output connecon (see B).
• Wire the mer C and NO contacts to the T/T 2 connecon (see C).
8. Replace the boiler’s front panel.
• Timer receives power from
the PC Board.
• The 24V AC mer circuit must
be electrically isolated from
the C and NO contacts that
connect to the T/T 2
terminal.
• Electrically isolated contacts C and NO close
the T/T 2 circuit on the boiler to acvate
recirculaon.
• Do not connect the NC terminal to the PC
Board (if the mer includes an NC terminal).
• Connecons C, NO and NC should not be
connected to mer 24V AC input terminals.
Note: Do not connect the mer to any of the 120V terminals on the PC Board or to any other 120V components.
Timer Terminals
DHW_Pump Terminal
Recirculaon
Pump
T/T 2
24V AC for
External Output
CNO NC
T
A
B
C
24V AC Input
Terminals