How do you know if your Thermal Release Valve or Gas Control Thermostat is defective? My pilot stays lit and when I turn dial to higher heat, the burner comes on for a second then both go out. GE says it's probably the TRD. A repairman came out and said it was the thermostat. To check the TRD the burner has to come out. I'm worried that once I get the new thermostat in Tuesday it won't solve the problem, then the repairman will have to return the second time when I order the TRD from GE.