Lennox O23 User Manual

Page 32
CHECK:
1−UNIT POWER
2−TRANSFORMER
3−LIMIT SWITCH
START
IS
24VAC ACROSS
R & C?
YES
JUMPER ACROSS
SCREWS R & G
YES
DOES UNIT
OPERATE?
NO
NO
IS
BLOWER
RUNNING ON HIGH
SPEED?
NO
IS
120VAC ACROSS
N & A?
REPLACE
BCC2
NO
YES
YES
CHECK BLOWER
WIRING AND
BLOWER
IS
120VAC ACROSS
N & ACC?
NO
REPLACE
BCC2
YES
JUMPER ACROSS
R &W
(REMOVE R & G JUMPER)
IS
UNIT LIT?
NO
CHECK:
1−PRIMARY CONTROL
2−IGNITION TRANSFORMER
3−FUEL PUMP
4−ELECTRODES
5−LIMIT SWITCH(ES)
YES
IS BLOWER
RUNNING ON LOW
SPEED, 45 SEC.
AFTER FURNACE LIGHTS?
NO
IS
120VAC ACROSS
N & H?
YES
IS
24VAC ACROSS
C & V?
REPLACE
BCC2
NO
NO
CHECK
WIRING
YES
IS
120VAC ACROSS
N & ACC?
YES
REMOVE
R & W
JUMPER
AFTER
THE SELECTED
TIME, DOES THE
BLOWER TURN
OFF?
YES
NO
YES
REPLACE
BCC2
END OF TEST
BCC2 / BCC3
TROUBLESHOOTING
FLOWCHART
NO
REPLACE
BCC2
CHECK BLOWER
WIRING AND
BLOWER

Lennox O23 Specifications

General

Brand	Lennox
Model	O23
Category	Furnace
Language	English