I am hooking up this furnace in my wood shop. Natural gas, 120vt. Here is the problem:
I have a manual thermostat hooked up to it, I turn it on to call for heat and the spark ignition kicks on and lights the pilot, the pilot proves itself and the spark stops (it is a 3 wire pilot). After a short amount of time the burners kick on and preheats, after the time delay the blower motor kicks on and instantaneously the burners go out and the blower runs through its cycle and then shuts off and then the whole procedure starts again.

Could there be a short in the gas valve that is causing this to happen? I have watched it happen several times and it truly is instantaneous when the blower kicks on the burners go out which is what is leading me to the electrical short theory.

Any help is appreciated.

Brian