30 year old forced air unit that I want to test to see if it runs and if it can be repaired but the gas service is currently turned of to the property. I have power and I can hear the hum of the 24volt transmitter can I get the fan to run without fuel? Thank you

Furnace should have a HI-lO switch. The Hi-lo switch turns the blower motor on when temperature in the heat chamber reaches a certain level. Turns the blower off when drops. This prevents the fan from blowing cold air while the heat chamber is getting up to temperature.

You could by pass the Hi-LO switch but would be easier to simply pull the blower and motor out an connect it to a directly to a power source.

Open lower compartment, you should find the blower assembly on a rail system. Disconnect it electrically. Slide entire assembly out and connect it directly to a power source. Clean every thing while you have it out.