Have a 50-year-old (?) natural gas wall heater in my apartment. Thermostat is connected to gas valve in heater by 2 wires. No evidence of transformer or low voltage (ie, 30 vac) on the wires.
Symptom is that the 'stat won't open the valve. If I short the terminals for just a second, the valve opens, and shuts at the appropriate temperature. (I since have read that it's not a good idea to short those terminals together; it could damage the valve, or some other component.)
What replacement thermostat should I be looking for? All I see are multi-wire types that require a transformer voltage. Will any mercury-bulb type work? (That's what the old one was.)
I'm also curious where the voltage comes from to operate the valve. Is this generated by the thermocouple / sensor next to the pilot flame?
Suggestions welcome.
Thanks,