Lennox G21Q Series Unit Information

Page 62
NO
NO
NO
YES
YES
"V" BLOWER ICM2 MOTOR AND VSP2−1 BLOWER CONTROL BOARD
TROUBLESHOOTING FLOW CHART
DOES UNIT OPERATE?
CHECK:
1−UNIT POWER
2−INTERLOCK SWITCH
3−TRANSFORMER
4−LIMIT SWITCH
REPLACE VSP2−1.
END OF COOLING TEST
CHECK UNIT WIRING
AND IF CORRECT
REPLACE THE
VSP2−1.
COOLING MODE
NO
YES
YES
YES
IS BLOWER ON HIGH SPEED AND ARE DS1 AND
DS3 LIT? DOES THE CFM" LED−DS4 LIGHT
BLINK ONCE FOR EVERY 100 CFM SELECTED IN
THE TABLES ON PAGES 8 AND 9.?
IN ADDITION TO R AND G,
JUMPER R AND DS.
IS 24 VOLTS PRESENT
ACROSS THE
ACCESSORY RELAY COIL?
IS BLOWER ON LOW SPEED AND IS
ON/OFF" LED−DS3 LIT? CFM" LED−
DS4 LIGHT SHOULD BLINK ONCE FOR
EVERY 100 CFM SELECTED IN THE
TABLES ON PAGES 8 AND 9.
CHECK UNIT WIRING AND
IF CORRECT, REPLACE
VSP2−1.
PLACE JUMPER ACROSS R AND G.
IS 24VAC ACROSS
R AND C?
NO
NO
YES
YES
DOES UNIT OPERATE?
CHECK:
1−UNIT POWER
2−INTERLOCK SWITCH
3−TRANSFORMER
4−LIMIT SWITCH
END OF TEST
REPLACE THE VSP2−1.
HEATING MODE
NO
YES
YES
YES
AFTER THE SELECTED
TIME, DOES BLOWER
TURN OFF?
PLACE HTG. BLOWER"
JUMPER IN POSITION #1.
R AND W1 REMAIN JUMPERED.
1−CHECK UNIT WIRING AND IF
CORRECT, REPLACE
VSP2−1.
PLACE HTG. BLOWER" JUMPER IN POSITION
#2. PLACE JUMPER ACROSS R AND W1. WAIT 75
SECOND FOR PREPURGE AND FANON" DELAY.
IS 24VAC ACROSS
R AND C?
2−BREAK AND REMAKE JUMP
ER (R TO W1).
3−AFTER 30−35 SECOND
PURGE, IS 24VAC PRESENT
AT GAS VALVE?
REPLACE VSP2−1.
REMOVE JUMPERS
YES
NO
CHECK UNIT WIRING
AND IF CORRECT,
REPLACE VSP2−1.
NO
IS 24 VOLTS PRESENT
ACROSS THE
ACCESSORY RELAY COIL
?
IS BLOWER ON LOW SPEED AND IS ON/OFF" LED−
DS3 LIT? CFM" LED−DS4 LIGHT SHOULD BLINK
ONCE FOR EVERY 100 CFM SELECTED IN THE
TABLES ON PAGES 8 AND 9.
DOES BLOWER SHIFT TO HEAT SPEED
AND IS HEAT" LED−DS2 ON? DOES
THE CFM" LED−DS4 LIGHT BLINK
ONCE FOR EVERY 100 CFM SELECTED
IN THE TABLES ON PAGES 8 AND 9?
NO

Lennox G21Q Series Specifications

General

Brand	Lennox
Model	G21Q Series
Category	Industrial Equipment
Language	English