Rheem RGDA-100A-AR Furnace

[HayZee518]

the thermocouple generates a millivolt voltage that is applied to the pilot valve inside the main valve. there is a tiny electro magnet that holds the pilot valve spool open when it's energized. if you ever saw a hot water heater where you have to hold a button "down" for three minutes, this is a case where the thermocouple needs to heat up and generate a voltage for the pilot valve.

[Tillberry]

Pilot light goes out intermittently. No wind or external influance. Suspect thermocouple. Any ideas?