8
OPERATING INSTRUCTIONS
The Unitary Package Heating,
Cooling Unit has been carefully
designed and built to provide
reliable operating performance
when installed and maintained
correctly.
CONTROL SYSTEM
DESCRIPTION
The unit is controlled on both
heating and cooling by a low
voltage wall mounted thermostat.
Any standard 24-volt heat/cool
thermostat intended to control a
gas-heating unit with cooling can
be made to work with the unit.
A room thermostat is basically a
switch used to direct 24 volt power
from the “R” terminal to its W, Y,
and G terminals, according to the
function being demanded by the
user. Sometimes an electronic
thermostat needs to be powered
with 24 volts via connection to an
additional “C” or “Common”
terminal, typically if its display is
backlit. If the thermostat demands
that the “C” connection be made at
the thermostat wiring terminals,
then please order the additional
black lead that will insert into the
unit’s low voltage connector, Part
No. 18BK23Y-024.
Heating and cooling will be cycled
on, as dictated by the setting of the
wall thermostat. In this mode, the
room-side fan will run at factory-
predetermined speeds for heating
and cooling.
IMPORTANT: The factory-set
indoor fan speeds must not be
changed. The product safety
certification relies on fan speeds
being coordinated with specific
heater sizes.
The indoor fan will be off when
neither heating nor cooling are
required, if the fan switch on the
thermostat is set to “AUTO”. If the
fan switch is set to “ON”, the indoor
fan will circulate air continuously on
low speed, until there is a call for
heating or cooling.
To get reasonable comfort and
energy consumption, it is
recommended that wall mounted
thermostats be set at 21
°
C (70
°
F)
for heating and 25
°
C (77
°
F) for
cooling.
Over-adjusting the thermostat will
not increase the rate at which a
unit will heat or cool the space; it is
merely an on-off switch that
responds to temperature.
ATTENTION:
Do not place the wall
thermostat in locations where it
cannot detect true room
temperature, such as in direct
sunlight or near air registers. Also
beware of drafts flowing through
the thermostat wiring hole.
