Installation Guide

Rinnai Tankless Water Heater Installation and Operation Manual 77
This section applies to CXP models only.
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 is desired, then installation of an MC-195T-US
Timer/controller or Wi-Fi Module is required.
Figure 83
Fixed schedule recirculation for CXP models requires the installation of the Wi-Fi Module or MC-
195T-US controller.
1
If the Wi-Fi Module or MC-195T-US controller is not installed, temporary pump operation can be
initiated by resetting power to the appliance (see section "3.6 Accessories" for part numbers). Visit
rinnai.us/wifi for more information.
Note: Recirculation parameter setting
04
must be set to your circulation mode. See section “4.13
Configure Parameter Settings” for more information.
1
DO NOT install the Wi-Fi Module and MC-195T-US together as they are NOT compatible
accessories.
To remove air, drain the water during pump operation. If the air is not fully removed, the pump could
run dry.
A thermal bypass valve can be installed with water heaters to operate recirculation without a
dedicated return line. The thermal bypass valve should be installed between the hot and cold line at
the farthest fixture in the plumbing system. Refer to section “5.7.2 Recirculation (Crossover Mode)”
for additional details.
NOTE: Thermal bypass valve should only be used for Crossover Mode Recirculation systems.
Fixed recirculation schedule requires the installation of one of the following controllers to set time
intervals and duration of recirculation system operation. Smart-Circ™ is automatically disabled if
a scheduling controller (MC195T-US/ Wi-Fi Module) is installed.
MC-195T-US Timer/Controller
Wired in digital control with integrated
timer function for recirculation control.
Wi-Fi Module
Wired in digital control with integrated
timer function for recirculation control.
Figure 84
Figure 82
Rinnai offers the thermal bypass
valve. Refer to section “3.6
Accessories” for additional details.