Rinnai I Series Technical Bulletin

3 TB-158
7/2019
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

Rinnai I Series Specifications

General

Brand	Rinnai
Model	I Series
Category	Boiler
Language	English