Page 38
CHECK:
1-UNIT POWER
2-INTERLOCK SWITCH
3-TRANSFORMER
4-LIMIT SWITCH
START
IS
24VAC ACROSS
R & T?
YES
JUMPER ACROSS
SCREWS R & G
YES
DOES UNIT
OPERATE?
NO
NO
IS
BLOWER
RUNNING ON HIGH
SPEED?
NO
IS
120VAC ACROSS
N1 & A?
REPLACE
BCC
NO
YES
YES
CHECK BLOWER
WIRING AND
BLOWER
IS
120VAC ACROSS
N1 & ACC?
NO
REPLACE
BCC
YES
JUMPER ACROSS
R &W
(REMOVE R & G JUMPER)
IS
COMB. AIR BLOWER
ON?
NO
REPLACE
BCC
NO
IS
120VAC ACROSS
N1 & CAB?
CHECK
COMBUSTION
AIR BLOWER
YES
YES
ARE BURNERS
LIT?
NO
CHECK:
1-COMBUSTION AIR BLOWER
2-IGNITION CONTROL
3-GAS VALVE
4-IGNITOR
5-LIMIT SWITCHES
6-PROVE SWITCH
YES
IS BLOWER
RUNNING ON LOW
SPEED, 45 SEC.
AFTER FURNACE
LIGHTS?
NO
IS
120VAC ACROSS
N1 & H?
YES
IS
24VAC ACROSS
T & V?
REPLACE
BCC
NO
NO
CHECK
WIRING
YES
IS
120VAC ACROSS
N1 & ACC?
YES
REMOVE
R & W
JUMPER
AFTER
THE SELECTED
TIME, DOES THE
BLOWER TURN
OFF?
YES
NO
YES
REPLACE
BCC
END OF TEST
BCC
TROUBLESHOOTING
FLOWCHART
NO
REPLACE
BCC
CHECK BLOWER
WIRING AND
BLOWER
FIGURE 43
CHECK CIRCUIT BREAKER.
RESET IF NECESSARY.