Rinnai MC-503RC Installation And Operation Manual page 15

Wireless and Wired Water Controllers
When installing combinations of both wired and wireless controllers, all wired water controllers
MUST BE connected before the wireless water controllers are assigned to a transceiver
channel.
Wired water controllers can only be added to an existing wireless installation when:
• all wireless transceiver channels have been unassigned
• all wireless controllers have been reset
When the wireless transceiver is installed it automatically detects any wired water controllers
already connected to the water heater. The LEDs of the channels assigned to wired controllers
will slow flash.
The channels for wired water controllers are assigned in sequence as follows:
• MC100V or MC91 (programmed as a master controller) will automatically be assigned to
the MC channel
• BC100V or MC91 (not programmed as a master controller) will automatically be assigned to
an available channel other than the MC channel
• Install the wireless water controllers to any unassigned channels following steps outlined on
page 
Rinnai New Zealand Wireless Installation and Operation: C 03-09
5