035-15267-002 Rev. B (0304)
2
Unitary Products Group
C
ongratulations . . .
On your purchase of one of the most versatile furnaces available in the industry today. This compact, energy-efficient furnace
has been precision designed, manufactured of high-quality materials and has passed many rigorous inspections and tests to
ensure many years of satisfactory service. This booklet is meant to increase your understanding of your unit, tell you how to
operate it efficiently and how to obtain the greatest measure of comfort at the lowest operating expense. Please read this book-
let thoroughly. We appreciate your interest in our product and your decision to purchase our furnace. Enjoy your comfort.
INTRODUCTION
TO OPERATE FURNACE
1.
Be sure electrical power to fur-
nace is turned on at the house-
hold service box.
2.
Set wall thermostat to the
desired temperature.
3.
If furnace is equipped with Air
Conditioning, the System
Switch, located at the wall ther-
mostat, must be turned to
HEAT in order for the furnace
to operate in the heating mode.
The interlock system usually con-
tains a heat-cool switch which
must be turned to either HEAT or
COOL to activate either heating or
cooling operation.
If an interlock system has not been
provided, the electrical supply to
the furnace must be turned OFF at
the household service box, when
the air conditioner is being used.
When operating the furnace, the
electrical supply to the air condi-
tioner must be turned OFF.
TO SHUT FURNACE OFF
1.
Turn thermostat to its lowest
setting.
NOTE:
Furnace will still operate if
room temperature falls below ther-
mostat setting.
2.
For complete shut-down turn
off electrical power at the
household service box.
SEQUENCE OF
OPERATION
When room thermostat calls for
heat, 24-volt power is supplied to
the heating element switches. As
soon as the first heating element
switch closes, the blower starts
and power is supplied to the first
heating element. Each additional
element is staged on in succes-
sive intervals.
When the room thermostat is satis-
fied and no more heat is required,
the elements sequence off in the
reverse order and the blower will
then turn off.
LIMIT CONTROLS
Each element has an automatic
limit switch which is wired into the
circuit and shuts off power to that
element if the heat at that point
exceeds the allowable maximum
heat.
BLOWER REMOVAL
NOTE:
Only authorized service
technicians should remove the
blower.
To remove blower from furnace,
turn off power at household service
box, turn furnace circuit breakers
OFF. Disconnect wiring to blower,
and remove five (5) screws holding
blower in furnace and slide blower
out from front of the furnace. See
Figure 1.
Re-install blower in reverse order
when assembling back into fur-
nace.
To avoid the possibility of
electrical shock do not
open electrical box pan-
els.
If you have an air condi-
tioner which does not
use the furnace blower
for air distribution and
operates completely
independent of the fur-
nace, the thermostat
system must have an
interlock to prevent the
furnace and air condi-
tioner from operating at
the same time. Such
operation could cause
equipment damage,
energy waste and over-
heating of the home.
FIGURE 1
UL
R
FILTER (IN
DOWNFLOW
ONLY) *
CAVITY
FOR
COIL
THERMOSTAT
WIRES
CIRCUIT
BREAKERS
ELECTRIC
PANEL
FIELD WIRING
PROTECTIVE
SHIELD
Filter in the front panel when louvered doors
are used. Filter located in base for upflow units.
*