through the sight glass or window on the blower access door. The
control indicates status with the LED on continuously, rapid
flashing, or a code composed of 2 digits. (The first digit is the
number of short flashes, the second is the number of longs flashes.)
For an explanation of status codes, refer to service label (See Fig.
8) located on blower access door or the Troubleshooting Guide.
The control stores 1 status code (the last status code to occur) for
a period of 48 hr or until the 115- or 24-v power is interrupted.
NOTE:
Look into blower access door sight glass for current LED
status BEFORE removing the blower access door. Removing
blower access door will open blower access door switch and
terminate 115-v power to control, and status code will be erased.
1. To retrieve status code, proceed with the following:
NOTE:
NO thermostat signal shall be present at control, and all
blower off delays must be completed.
a. Leave 115-v power to furnace turned on.
b. Look into blower access door sight glass for current LED
status.
NOTE:
Leave blower access panel installed to maintain power to
control to view current LED status.
c. Remove control access door.
d. BRIEFLY remove either wire from the main limit switch
until LED goes out, then reconnect it.
NOTE:
If wire to main limit is disconnected longer than 4 sec,
main blower starts, and retrieval request is ignored.
2. When above items have been completed, the following will
occur:
a. LED flashes a status code 4 times. Record this status code
for further troubleshooting.
b. Inducer motor starts and continues to run the entire
component test.
c. Hot surface ignitor is energized for 15 sec, then de-
energized.
d. Main blower operates at heating speed for 10 sec, then
turns off.
e. Main blower operates at cooling speed for 10 sec, then
turns off.
f. Inducer motor stops.
Items a through e above will assist in furnace troubleshooting since
all components are functionally operated except the gas valve. This
procedure is also referred to as
″
Component Test.
″
3. Operate furnace through 1 heat cycle to test for proper
operation and check LED status.
4. If furnace is operating properly and LED indicates proper
operation, replace control access door.
5. Component Test can also be initiated by performing the
following:
a. Remove control access door.
b. Remove blower access door.
c. Manually close blower access door switch.
Fig. 7—Furnace Control
A00292
G
R
Y
W
Com
24V
HUM
3-AMP FUSE
HUMIDIFIER TERMINAL
(24-VAC 0.5 AMP MAX)
LED OPERATION &
DIAGNOSTIC LIGHT
HARNESS CONNECTOR
24-V TRANSFORMER SEC-2
SPARE-1
SPARE-2
EAC-1 (BLACK)
EAC-ELECTRONIC AIR CLEANER
TERMINALS (115-VAC 1 AMP MAX)
EAC-2 (WHITE)
115-VAC (L2) NEUTRAL
CONNECTION
24-V THERMOSTAT
TERMINALS
BLOWER SPEED
SELECTION TERMINALS
INDUCER MOTOR
CONNECTOR
115-VAC (L1)
POWER SUPPLY
HOT SURFACE
IGNITOR CONNECTOR
HEAT
COOL
BLOWER OFF DELAY
ADJUSTMENT SWITCH
SEC-1
TEST/TWIN
7