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Rinnai Tankless Water Heater Installation and Operation Manual
5.7 Configuring Recirculation
Smart-Circ™ is the factory default setting for recirculation. Smart-Circ™ allows the water heater to identify
when hot water is used, and then operates recirculation on subsequent days to reduce wait time for hot water.
If a fixed recirculation schedule or on demand device is desired, then installation of an MC-195T-US Timer/
controller or control·r™ Wi-Fi Module is required.
Fixed recirculation schedule requires the installation of one of the following controllers to set time intervals
and duration of recirculation system operation.
MC-195T-US Timer/Controller
Wired in digital control with integrated
timer function for recirculation control.
control
•
r
™
Wi-Fi Module
Wired in digital control with integrated
timer function for recirculation control.
Not Included
A Thermal Bypass Valve can be installed with water heaters to run recirculation without a dedicated return
line. The Thermal Bypass Valve should be installed between the hot and cold line at the furthest fixture in
the plumbing system. Refer to the Crossover Mode section of this manual for additional details.
NOTE: Thermal Bypass Valve should only be used for Crossover Mode Recirculation systems.
Only one Rinnai approved thermal bypass valve can be used per REP model.
Thermal Bypass Valve
Cold
Hot
Figure 76
Figure 77
Figure 78
Figure 79
Not Included
Fixed schedule recirculation for REP models requires the installation of the control·r™ Wi-Fi Module or MC-
195T-US controller.
1
If the control•r™ Wi-Fi Module or MC-195T-US controller are not installed, temporary pump operation can be
initiated by resetting power to the appliance.
On Demand push buttons and motion sensors require installation of a control·r™ (see section "3.5
Accessories" for part numbers). Visit rinnai.us/wifi for more information.
Note: Recirculation parameter setting
04
must be set to your circulation mode. See “Parameter Settings”
section in this document for more information.
1
DO NOT install the control•r™ Wi-Fi Module and MC-195T-US together as they are NOT compatible
accessories.
The default setting for parameter setting 16 is "A: Max." The pump speed can be changed for noise levels.
See section "7.4 Pressure Drop and Water Flow Curves" for pump curves. To remove air, drain the water
during pump operation. If the air is not fully removed, the pump could run dry.
