2
Activating the “SYSTEM OFF” switch should be done
with care because there will be no heating or cooling
operation even though there may be a demand - a
room could potentially go into a freezing condition.
Once a comfortable temperature setting is
established, no other adjustments are necessary,
except for fan speed, which is adjusted using the fan
speed control knob at the unit.
WALL THERMOSTAT OPERATION
Heat
Sets the unit into heating mode.
Initiates heating when room
temperature falls below set point.
Off
Disables heating and cooling
modes, but allows control of fan.
Cool
Sets the unit into cooling mode.
Initiates cooling when room
temperature rises above set point.
Auto
(not shown)
Found on automatic changeover
thermostats only. Allows the
thermostat to decide whether it
should be in the heating or cooling
mode. Usually a 4 F
°
differential or
“deadband” will exist between
heating and cooling set points to
prevent rapid switching between
modes.
Adjustable
Temperature
Setting
Establishes the “set point”, or
desired room temperature.
Fan On
Synonymous with “Fan
Continuous”. Fan will continue to
run after the heating and cooling
function has cycled off. Fan will
continue to run even when mode
switch is in Off position.
Fan Auto
Synonymous with “Fan
Intermittent”. Fan will cycle on and
off with the heating cycle or
cooling cycle, and will not operate
between cycles.
UNIT MOUNTED CONTROLS
Dial Plate and Rotary Switch
ROTARY SWITCH
The rotary switch and dial plate are found under the
control door, which is located at the top right corner
of the unit. The knob can be rotated to the left or to
the right of the “Off” position. Heating output is not
affected by fan speed. The settings are addressed in
the following table:
ROTARY SWITCH OPERATION
Fan ‘3’
High Speed. Selects highest fan
speed for maximum cooling capacity,
maximum airflow, maximum air throw,
hence maximum air circulation.
Fan ‘2’
Medium Speed. Selects medium fan
speed for a slightly reduced cooling
capacity, at midrange airflow, and
operation at a reduced sound level.
Fan ‘1’
Low Speed. Selects lowest fan speed
for maximum air dehumidification and
operation at the lowest sound level.
IMPORTANT:
If the compressor is running in cooling
mode, and then the unit is switched off, wait at least
three minutes before switching the unit back on. This
prevents cycling the compressor overload switch
unnecessarily. Similarly, if the power has been
interrupted, it is recommended that the unit be
switched off and not switched on again until power
has been restored for at least 3 minutes.
NOTE:
The unit uses time delay relays to respond to
commands from the wall thermostat. Therefore, there
will be delayed responses when switching from one
function to another – please be patient.
FRESH AIR CONTROL
Refer to the standard unit Installation Instructions for
operation and location of fresh air door control lever.
