Lennox EL280DF Series Unit Information page 31

Troubleshooting: Continuous Fan Sequence of Operation
THERMOSTAT CALLS FOR FIRST STAGE COOL.
INDOOR BLOWER RAMPS TO FIRST STAGE
COOLING SPEED AFTER A 2-SECOND DELAY.
FIRST-STAGE COOL DEMAND SATISFIED?
YES
SECOND STAGE COOL DEMAND
INDOOR BLOWER RAMPS TO SECOND
STAGE COOL SPEED
SECOND STAGE COOL DEMAND SATISFIED?
INDOOR BLOWER RAMPS DOWN TO FIRST STAGE
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
NO
YES
COOL SPEED.
YES
THERMOSTAT CALLS FOR FIRST-STAGE HEAT.
AFTER 45-SECOND DELAY, INDOOR BLOWER
SWITCHES TO LOW HEAT SPEED.
FIRST-STAGE HEAT DEMAND SATISFIED.
THERMOSTAT CALLS FOR SECOND-STAGE HEAT.
INDOOR BLOWER SWITCHES TO HIGH HEAT SPEED
AFTER 30-SECOND RECOGNITION PERIOD.
SECOND-STAGE HEAT DEMAND SATISFIED.
INDOOR BLOWER RAMPS DOWN TO LOW
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YES
NO
YES
YES
YES
HEAT SPEED.
YES