Troubleshooting a Lennox LF24-45A-5

Check the heater's thermostat if the heater is not coming on. Like other heating appliances, the Lennox LF24-45A-5 uses a thermostat and the heater only kicks on when the air temperature is lower than the thermostat temperature. Therefore, turn the thermostat temperature up above the air temperature to see if the heater activates.

Verify that the heater is receiving electrical power. First, make sure the unit's power cord is firmly plugged into the outlet and not loose or damaged. If the cord is plugged in, check the breaker box to see if the heater's breaker is tripped, and flip the breaker switch if it is tripped. It is also wise to make sure that the circuit has not blown a fuse.

Check that the heater's gas supply is working normally. These heaters are equipped with manual gas shutoff valves; close the shutoff valve if it is open. If there is no problem at the gas valve, contact your gas provider to make sure your service has not been interrupted and that you are not located in an outage area.