That's the thing Dinger, this ISN'T a "Thermocoupler" it is a "Generator". There ARE "thermocouplers" used in heaters, but not mine. This is what I always thought about them. The thermocoupler is a mechanical device that shuts off the gas flow like a faucet. They have a copper tub that goes to the valve. I thought this was the only way it worked, period. The wires going to the thermostat, I never thought about it, didn't have a clue. I guess I assumed there was some sort of transformer or something that produced 12 volts like other low voltage items. With that 12 Volts the gas valve was opened and closed.
Well, yesterday I broke down and went to work on fixing my wall heater. These freezing cold California mornings were getting to me.
So I bypassed the thermostat and nothing. This told me the valve wasn't getting the the 12 volts to open, or that the valve was bad. Well, of course I learned that there is no transformer, there is no 12 volts.
My heater (as most I learned) didn't have a thermocoupler, it had a "generator". A "thermocoupler" looking device (the generator) with wires that go to the valve. The milivolts it creates opens the valve!
By the way, I bought a new one, but then when removing the old one I noticed that it was all crusted with ashes. I removed it and took it to the garage for a good cleaning with a scuff pad and blew it all out with compressed air. I reinstalled it and it worked like a charm! The ashes were "insulating" the heat from reaching it.
Anyway, I was dumbfounded with this new found knowledge.
It doesn't take much to get me excited.