[NewellCrazy]

You've already eliminated the thermostat as the culprit, which suggests checklist item #4. Before concentrating on the gas valve, however, I'd perform one more simple test to make sure the thermostat cable isn't shorted. With all power off, remove the wires from the thermostat (there are probably only 2) and use an ohmmeter to check for continuity between the two. If you get any ohmmeter reading (continuity) it suggests those wires are probably shorted somewhere between the thermostat and the gas valve or the circuit board. Good luck