Well, I also had a problem with my powervent PVG62-50T63-3NHV. After changing the thermocouple it was short cycling. I called Amrican Heater and they suggested a new gas valve/thermostat. Before I plunked down $125 plus shipping I thought I’d take the top of the electrical box off and I immediatley noticed that the clear vent tube that goes from the air switch to the motor had several drops of water in it. Took that off, drained it and for good measure I ran a piece of wire into both the air switcha as well into the motor connection; popped the hose back on and … HOT WATER.
Thanks for making this information available.