Record the code and repeat the disconnect and reconnect of the red
wire, recording each code until code 11 is displayed indicating no
additional codes. After the last code is displayed or after 2 minutes
in the code recall mode the control will return to normal standby
mode.
Step 2—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 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 control and not until all time delays are completed.
To Begin Component Self-Test:
Blower access panel door switch opens 115-v power to
control board. No component operation can occur. Caution
must be taken when manually closing this switch for service
purposes. Failure to follow this warning could result in
electrical shock, personal injury, or death.
1. Remove blower access door.
2. Disconnect thermostat R lead from furnace control.
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 termi-
nals. (See Fig. 12.)
NOTE:
If TEST/TWIN and C
OM
-24v terminals are jumpered
loner than 2 sec, LED will flash rapidly and ignore status code
retrieval request.
Component test sequence for 2-stage furnace is as follows:
a. LED will display previous status code 4 times.
b. Inducer motor starts on high-speed and continues to run
until Step g of component test sequence.
c. Hot surface igniter is energized for 15 sec, then off.
d. Blower motor operates on LO-HEAT speed for 10 sec.
e. Blower motor operates on HI-HEAT speed for 10 sec.
f. Blower motor operates on COOL speed for 10 sec.
g. Inducer motor goes to low-speed for 10 sec, then stops.
5. Reconnect R lead to furnace control, remove tape from blower
door switch, and re-install 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.
Fig. 14—Inducer Housing Drain Tube Cap
A99118
Fig. 15—Funnel in Drain and Antifreeze
Running Through Trap
A99119
11
