Lennox EL280UH Installation Instructions Manual page 49

Troubleshooting: Continuous Fan Sequence of Operation
CONTINUOUS LOW SPEED FAN SEQUENCE OF OPERATION
MANUAL FAN SELECTION MADE AT THERMOSTAT.
AFTER 2 SECOND DELAY, INDOOR BLOWER IS
ENERGIZED ON CONTINUOUS FAN SPEED.
YES YES
THERMOSTAT CALLS FOR FIRST STAGE COOL. THERMOSTAT CALLS FOR FIRST−STAGE HEAT.
YES
YES
INDOOR BLOWER RAMPS TO FIRST STAGE AFTER 45−SECOND DELAY, INDOOR BLOWER
COOLING SPEED AFTER A 2−SECOND DELAY. SWITCHES TO LOW HEAT SPEED.
FIRST−STAGE COOL DEMAND SATISFIED? FIRST−STAGE HEAT DEMAND SATISFIED.
YES YES
NO
NO
SECOND STAGE COOL DEMAND THERMOSTAT CALLS FOR SECOND−STAGE HEAT.
YES
INDOOR BLOWER RAMPS TO SECOND INDOOR BLOWER SWITCHES TO HIGH HEAT SPEED
STAGE COOL SPEED AFTER 30−SECOND RECOGNITION PERIOD.
YES
SECOND STAGE COOL DEMAND SATISFIED? SECOND−STAGE HEAT DEMAND SATISFIED.
YES
YES
INDOOR BLOWER RAMPS DOWN TO FIRST STAGE INDOOR BLOWER RAMPS DOWN TO LOW
COOL SPEED. HEAT SPEED.
Page 49