To retrieve previous codes, remove 1 of the red main limit wires
for 1 to 4 sec until the LED light goes out, then reconnect it. (Do
not leave red wire disconnected for longer periods of time as the
control will assume an overtemperature condition exists and will
respond with blower operation.) This places the control in the
status recall mode and displays the first code stored in memory.
Record the code. After the last code is displayed the control will
perform the component test, and then return to normal standby
mode.
B.
Component Test
NOTE:
The furnace control component test allows all compo-
nents to run for a short time; except the gas valve and humidifier
terminal HUM are not energized for safety reasons. The EAC-1
terminal is energized when the blower is energized. This feature
helps diagnose a system problem in case of a component failure.
The component test feature will not operate if any thermostat
signal is present at the control and not until all time delays are
completed.
NOTE:
Record the status code BEFORE opening the blower
access door and before shutting off power to furnace. Opening the
blower access door will open the blower door switch and shut off
power within the furnace. When power to the furnace is shut off by
either method, the status code will be lost because the code is not
stored while power is removed for any reason.
To Begin Component Self-Test:
WARNING:
UNIT MAY NOT OPERATE
Failure to follow this warning could result in electrical
shock, personal injury, or death.
Blower access panel door switch opens 115-v power to
control board. No component operation can occur. Cau-
tion must be taken when manually closing this switch for
service purposes.
1. Remove blower access door.
2. Disconnect the thermostat R lead from furnace control
board.
3. Manually close blower door switch.
4. For approximately 2 sec, short (jumper) the C
OM
-24v
terminal on control to the TEST/TWIN 3/16-in. quick-
connect terminal on control until LED turns off. Remove
jumper from terminals. (See Fig. 12.)
NOTE:
If TEST/TWIN and C
OM
-24v terminals are jumpered
longer than 2 sec, LED will flash rapidly and ignore component
test request.
Component test sequence for single-stage furnace is as follows:
a. LED will display status code 11 four times.
b. Inducer motor starts and continues to run until Step f. of
component test sequence.
c. After 7 sec the hot surface igniter is energized for 15 sec,
then off.
d. Blower motor operates on HEAT speed for 10 sec.
e. Blower motor operates on COOL speed for 10 sec.
f. Inducer motor stops.
5. Reconnect R lead to furnace control board, remove tape
from blower door switch, and reinstall blower door.
6. Operate furnace per instruction on outer door.
7. Verify furnace shut down by lowering thermostat setting
below room temperature.
8. Verify that furnace restarts by raising thermostat setting
above room temperature.
A99118
Fig. 14—Inducer Housing Drain Cap
A99119
Fig. 15—Funnel in Drain and Antifreeze Running
Through Trap
—11—
