Lennox 80MGF Series Manual page 28

80MGF TROUBLESHOOTING SEQUENCE − COOLING
80MGF TROUBLESHOOTING SEQUENCE − FAN ONLY
THERMOSTAT CALLS FOR COOLING.
YES
SYSTEM FAN SWITCHED
TO COOLING SPEED. COOLING
SEQUENCE RUNS TO COMPLETION.
SLOW FLASH
FAST FLASH
2 FLASH
3 FLASH
4 FLASH
5 FLASH
STEADY ON
LED: Slow flash rate.
REMAINS UNCHANGED THROUGHOUT COOLING CYCLE.
THERMOSTAT CALLS FOR COOLING.
COMPRESSOR CONTACTOR AND SYSTEM FAN
ENERGIZED AT COOLING SPEED AFTER
1 SECOND DELAY.
THERMOSTAT OPENS.
COMPRESSOR OFF.
SYSTEM FAN OFF AFTER COMPLETING
SELECTED DELAY INTERVAL
(At dip switches).
LED: Slow flash rate.
REMAINS UNCHANGED THROUGHOUT SEQUENCE.
MANUAL FAN SELECTION MADE AT THERMOSTAT.
CONTROL ENERGIZES SYSTEM FAN
AT HEATING SPEED.
THERMOSTAT CALLS FOR HEAT.
NO
NO
SYSTEM FAN ON AT HEATING SPEED
UNTIL MANUAL FAN IS SWITCHED
OFF AT THERMOSTAT.
LED CODES
NORMAL OPERATION. NO CALL FOR HEAT.
NORMAL OPERATION. CALL FOR HEAT.
SYSTEM LOCKOUT. FAILURE TO DETECT OR SUSTAIN FLAME.
.
PRESSURE SWITCH OPEN OR CLOSED.
HIGH LIMIT OR ROLLOUT SWITCH OPEN.
FLAME SENSED AND GAS VALVE NOT ENERGIZED.
CONTROL BOARD FAILURE.
Page 28
YES
SYSTEM FAN REMAINS ON HEATING SEQUENCE AND
RUNS THROUGH COMPLETION.