Installation Guide

VC Series Manual 33
How to use the Temperature Controller
The MC-91-2 controller is the standard temperature
controller that is supplied with the water heater. On
indoor models it is integrated into the front panel.
The MCC-91-2 controller is for commercial and
hydronic applicaons requiring higher temperatures.
When the MCC-91-2 controller is connected, these
higher temperatures are available on all controller
models in the system. Refer to the secon on
temperature ranges.
DO NOT repeatedly operate the water heater and
then use a hot water tap while the controller is
turned o. Operang the water heater in this way to
alternately produce hot water may cause water to
condense on the outside of internal parts and
accumulate in the water heater cabinet.
Dimensions (inches): 3.5 W x 4.75 H x 0.75 D
Temperature
Display
Priority
Indicator
Priority
Button
ON/OFF
Button
In Use
Indicator
Temperature
Selection
MC-91-2US
 Before operang, smell all around the appliance
area for gas. Be sure to smell next to the oor
because some gas is heavier than air and will sele
on the oor.
 Keep the area around the appliance clear and free
from combusble materials, gasoline, and other
ammable vapors and liquids.
 Always check the water temperature before
entering a shower or bath.
 Do not use this appliance if any part has been
under water. Immediately call a licensed
professional to inspect the appliance and to replace
any part of the control system and any gas control
which has been under water.
 Should overheang occur or the gas supply fail to
shut o, turn o the manual gas control valve to
the appliance.
 Do not adjust the DIP switch unless specically
instructed to do so.
 Do not use an extension cord or an adapter plug
with this appliance.
 Any alteraon to the appliance or its controls can
be dangerous and will void the warranty.
 If you install this water heater in an area that is
known to have hard water or that causes scale
build-up the water must be treated and/or the
heat exchanger ushed regularly. Rinnai provides
a “Scale Control System” that oers superior lime
scale prevenon and corrosion control by feeding
a blend of control compounds into the water
supply. Damage and repair due to corrosive
compounds in the air is not covered by warranty.
 Keep the air intake locaon free of chemicals such
as chlorine or bleach that produce fumes. These
fumes can damage components and reduce the
life of your appliance. Damage and repair due to
scale in the heat exchanger is not covered by
warranty.
WARNING