So I dragged my 2008 Classic 25fb AS out of storage yesterday and filled up the water tank. Damn Micropulse is reading full with a partially filled water tank but that is another problem. Connected the water hose and opened the hot water input and output values. I generally open the pressure relieve valve when filling the tank and when water starts to come out I close it.
So after I purged all the air out of all the faucets and checked for leaks I went to try the hot water heater. Flipped the gas switch. Nothing. Usually I can hear the water heater gas valve open and it will attempt to light.
So back outside and I pulled all the connections off and reseated them. Towel dried any parts that water got on. Still no go. I've had this happen once before and it appears if I get any water on the foam that covers the thermostat sensors behind the foam gasket it will not initiate gas start up. So I went back into the house and had some dinner and an hour or so later went out to try it and flip the switch and heard the valve open and the ignitor trying to light the water heater. Since there was still air in the propane line to the water heater it didn't light up on first cycle.
The youTube video shows what is behind the foam gasket