Lennox International Inc. EL280UH Furnace User 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.
THERMOSTAT CALLS FOR FIRST−STAGE HEAT.THERMOSTAT CALLS FOR FIRST STAGE COOL.
YES
YES
AFTER 45−SECOND DELAY, INDOOR BLOWER
SWITCHES TO LOW HEAT SPEED.
FIRST−STAGE HEAT DEMAND SATISFIED.
YES
NO
THERMOSTAT CALLS FOR SECOND−STAGE HEAT.
YES
INDOOR BLOWER SWITCHES TO HIGH HEAT SPEED
AFTER 30−SECOND RECOGNITION PERIOD.
SECOND−STAGE HEAT DEMAND SATISFIED.
YES
YES
INDOOR BLOWER RAMPS DOWN TO LOW
HEAT SPEED.
INDOOR BLOWER RAMPS TO FIRST STAGE
COOLING SPEED AFTER A 2−SECOND DELAY.
FIRST−STAGE COOL DEMAND SATISFIED?
YES
NO
SECOND STAGE COOL DEMAND SATISFIED?
INDOOR BLOWER RAMPS TO SECOND
STAGE COOL SPEED
YES
SECOND STAGE COOL DEMAND
INDOOR BLOWER RAMPS DOWN TO FIRST STAGE
COOL SPEED.
YES YES