I was at a house today working on his furnaces and he wanted me to check out his pool heater because his pilot light was out. It had a powerpile on it, but it wasn't a standard 2 wire. It actually threaded into the gas valve like a thermocouple. I've looked online and it doesn't seem like they exist. Anyone familiar with these?
I have a teledyne Lara’s which might operate much the way you describe.  But also have some questions.  I believe the heater electrical system operates by way of a thermoelectric generator.  But since the pump/filter systems is powered by 115v, I assume the circulating water signals the burner to fire thereby heating the circulating water through the heater?
Deleting Attachment...