(7.) Inducer motor goes to low-speed.
Items (1.) through (7.) above will assist in furnace
troubleshooting since all components are function-
ally operated except the gas valve. This procedure is
also referred to as “Component Test Sequence.”
f. Check LED status.
g. If LED status indicates proper operation, RELEASE
BLOWER ACCESS DOOR SWITCH, replace blower
access door, and replace burner access door.
WIRING DIAGRAMS
Refer to Fig. 6 and 7 for wiring diagrams.
TROUBLESHOOTING
Refer to the service label. (See Fig. 9—Service Label.)
The Troubleshooting Guide following Fig. 9 can be a useful tool
in isolating furnace operation problems. Beginning with the word
“Start,” answer each question and follow the appropriate arrow to
the next item.
The Guide will help to identify the problem or failed component.
After replacing any component, verify correct operation sequence.
Fig. 8—Furnace Control
A00380
LHT
OFF
DLY
ON
OFF
W2
BLW
24-V-THERMOSTAT
TERMINALS
SETUP SWITCHES
LOW-HEAT ONLY AND
BLOWER OFF-DELAY
TWINNING AND/OR
COMPONENT TEST
TERMINAL
ACRDJ - AIR CONDITIONING
RELAY DISABLE JUMPER
TRANSFORMER 24-VAC
CONNECTIONS
PL1 - LOW VOLTAGE MAIN
HARNESS CONNECTOR
PL3 - ICM CONTROL
HARNESS CONNECTOR
HUMIDIFIER TERMINAL
(24-VAC 0.5 AMP MAX.)
3-AMP FUSE
LED OPERATION &
DIAGNOSTIC LIGHT
115-VAC (L2) NEUTRAL
CONNECTIONS
PL2 - HOT SURFACE
IGNITER & INDUCER
MOTOR CONNECTOR
115-VAC (L1) LINE
VOLTAGE CONNECTION
EAC-1 TERMINAL
(115-VAC 1.0 AMP MAX.)
BLOWER SPEED
SELECTION TERMINALS
HI HEAT
LO HEAT
SPARE-1
SPARE-2 COOL
Y1
DHUM
G
COM
24V
WW1
Y/Y2
R
TEST/TWIN
HUM
1 2 3
PL
T
A
CRDJ
0.5-AMP024 VAC
FUSE 3-AMP
SEC-1
SEC-2
PL1
NEUTRAL-L2
1
EAC-2
BHT/CLR
BHI/LOR
PL3 1
BLWR
COOL
SPARE-1
SPARE-2
1-AMP@115 VAC
EAC-1
PR-1
IDR
HSIR
IDM
IHI/LOR
PL2
1
HSI HI LO
STATU
S
COD
EL
E
D
HI HEA
T
LO HEA
T
L1
—8—
