Lennox Air Handler Transformer 24F86

About the Transformer

A furnace or air handler transformer is the component that decreases or increases the incoming voltage to power the unit. A faulty transformer can prevent the unit from heating. If there is no secondary 24 volt power to the thermostat, the unit trips a circuit breaker when it comes on, or you hear a consistent humming or vibrating noise, it's possible the transformer has failed.