[Kelvininin]

The water heater is fixed and you'll never guess what was causing the trouble.

during my troubleshooting process I replaced the copper tuning gas supply line since the existing line had a small kink. That didn't fix the problem. The heater was getting gas, plenty of it, the burner and tube assembly where clean. So logic dictated that there was something not right with the gas valve assembly.

So I did what any mechanically inclined cheap butthead would do... I serviced the non-serviceable valve. The valve is in great shape, diaphragm is perfect, seats are clean and no indication of wear, springs are good.... When inspecting the vent cap for the regulator, I found it was not properly machined leaving no flow path to equalize the atmospheric side of the regulator. Simple fix with a drill bit.

I now have a fully functioning water heater.