440 04 6001 00
7
Specifications subject to change without notice.
ELECTRICAL OPERATION HAZARD
Failure to follow this warning could result in personal
injury or death.
Disconnect 115vac electrical power before changing
speed tap.
!
WARNING
(Read following caution before changing taps).
UNIT DAMAGE HAZARD
To avoid operating outside the rise range and avoid
component damage:
Refer to the Air Delivery Tables to determine which
airflows and settings are allowed for proper heating
airflow. DO NOT use the highlighted settings for
Heating airflow. The highlighted settings are to be used
for Cooling and Continuous Fan ONLY.
CAUTION
!
Change the blower speed taps as required to maintain
proper temperature rise for Heating and Cooling as
described above. To change blower motor speed selections
for heating mode, remove blower motor lead from control
HEAT terminal(s). (See Figure 2) Select desired blower
motor speed lead(s) from the other motor leads and relocate
it/them to HEAT (heating blower tap) terminal(s). Reconnect
original lead on SPARE terminal.
Adjust Blower Off Delay (Heat Mode)
If desired, the main blower off time delay period may be
lengthened or shortened when operating in the heating
mode to provide greater comfort. For position and location
of jumpers on control center. (See Figure 2 and Figure 16)
The blower off-delay has four adjustable settings from 90
sec to 180 sec. (See Table 1) To change the blower off
delay setting, move the jumper from one set of pins on the
control to the pins used for the desired blower off delay.
Factory blower off-delay setting is 120 sec.
Table 1 – Blower Off Delay Jumper Positions
PINS
1 AND 2
2 AND 3
3 AND 4
4 AND 5
Time (in sec.)
90
120
150
180
Adjust Cooling Airflow
The cooling airflow can be set from the remaining blower
speed taps. Refer to the Air Delivery Table (see Table 5) in
these instructions.
FURNACE OVERHEATING HAZARD
Failure to follow this caution may result in reduced
furnace life.
Recheck temperature rise. It must be within limits
specified on the rating plate. Recommended operation
is at the mid--point of rise range or slightly above.
CAUTION
!
Adjust Thermostat Heat Anticipator
Mechanical thermostat:
Set thermostat heat anticipator to
match the amp. draw of the electrical components in the
R-W circuit. Accurate amp. draw readings can be obtained
at the wires normally connected to thermostat sub-base
terminals, R and W. The thermostat anticipator should NOT
be in the circuit while measuring current.
1. Remove thermostat from sub-base or from wall.
2. Connect an amp. meter across the R and W
sub-base terminals or R and W wires at wall.
3. Record amp. draw across terminals when furnace is
in low heat and after blower starts.
4. Set heat anticipator on thermostat per thermostat
instructions and install on sub-base or wall.
5. Install blower access door.
Electronic thermostat:
Set cycle rate for 3 cycles per hr.
Check Safety Controls
The flame sensor, gas valve, and pressure switch were all
checked in the Start
−
up procedure section as part of normal
operation.
1. Check Main Limit Switch
This control shuts off combustion system and
energizes air
−
circulating blower motor, if furnace
overheats. By using this method to check the temper-
ature limit control, it can be established that the limit is
functioning properly and that the limit will operate if
there is a restricted return
−
air supply or motor failure.
If the limit control does not function during this test,
the cause must be determined and corrected.
a. Run furnace for at least 5 minutes.
b. Gradually block off return air with a piece of
cardboard or sheet metal until the limit trips.
c. Unblock return air to permit normal circulation.
d. Burners will re
−
light when furnace cools down.
2. Check Pressure Switch(es)
This control proves operation of the draft inducer
blower.
a. Turn off 115
−
v power to furnace.
b. Disconnect inducer motor lead wires from wire
harness.
c. Turn on 115
−
v power to furnace.
d. Set thermostat to “call for heat” and wait 1 minute.
When low pressure switch is functioning properly, hot
surface igniter should
NOT
glow and control
diagnostic light flashes a status code 31. If hot
surface igniter glows when inducer motor is
disconnected, shut down furnace immediately.
e. Determine reason low pressure switch did not
function properly and correct condition.
f. Turn off 115
−
v power to furnace.
g. Reconnect inducer motor wires, replace door, and
turn on 115
−
v power.
h. Blower will run for 90 sec before beginning the call
for heat again.
i. Furnace should ignite normally.
Checklist
1. Put away tools and instruments. Clean up debris.
2. Verify that the jumper is removed from the TEST/
TWIN terminal. Verify that there is nothing plugged in-
to the PLT connector.
NOTE
: If there is a jumper connector plugged into PLT,
remove it and discard. (See Figure 2)
3. Verify that the Blower/Heat Off Delay jumpers are set
as desired. (See Figure 2 and Figure 16)
4. Verify that the blower (lower door in upflow position)
and control (“Main” or upper door in upflow position)
doors are properly installed.
5. Verify that the Status LED glows. If not, check that the
power supply is energized and that the blower door is
secure. See Figure 5 to interpret diagnostic codes
.
6. Cycle test furnace with room thermostat to be sure
that it operates properly with the room thermostat.
Check all modes including Heat, Cool and Fan.
7. Check operation of accessories per manufacturer’s
instructions.
8. Review Owner’s Manual with owner.
9. Attach literature packet to furnace.
