Lennox G20R series User Manual

Page 21
FIGURE 32
CHECK:
1-UNIT POWER
2-INTERLOCK SWITCH
3-TRANSFORMER
4-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
BCC
NO
YES
YES
CHECK BLOWER
WIRING AND
BLOWER
IS
120VAC ACROSS
N & ACC?
NO
REPLACE
BCC
YES
JUMPER ACROSS
R &W
(REMOVE R & G JUMPER)
IS
DAMPER MOTOR
ON?
NO
REPLACE
BCC
NO
IS
120VAC ACROSS
N & CAB?
CHECK
DAMPER MOTOR
WIRING AND
DAMPER MOTOR
YES
YES
IS
UNIT LIT?
NO
CHECK:
1-DAMPER MOTOR
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
N & H?
YES
IS
24VAC ACROSS
C & V?
REPLACE
BCC
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
BCC
END OF TEST
BCC
TROUBLESHOOTING
FLOWCHART
NO
REPLACE
BCC
CHECK BLOWER
WIRING AND
BLOWER
CHECK FUSE.
REPLACE IF NEEDED.

Lennox G20R series Specifications

General

Brand	Lennox
Model	G20R series
Category	Furnace
Language	English