I have an Aire-flo model AF80 forced air furnace that is not putting out any heat. The blower is working fine. I have tried the circuit breaker and replacing the thermostat but neither seems to work. Anyone have any suggestions?

Look for a status light on the front/blower panel. Observe & note activity (blinks) if present. Look for a label with codes & instructions, may be inside blower compartment or other panel.