Specifically - I have a State Industries, Inc. Censible 510 Model PRV 50 PBRT6 F 50 gallon gas water heater dated 1991 (S/N E93760685) and I want to replace the thermocouple.

Usually, a thermocouple simply slides in/out or has a screw base to hold it in place - this one does not or at least I cannot see any way to remove it.

I cannot find a service manual anywhere on the web and a phone conversation with Tech Support at State Industries did not help - the person did not have the manual or didn't bother trying to find one and they also gave me the standard answer of "it should simply slide out," which of course it doesn't.

Anyone have any suggestions - other than call a plumber?

Thanks,
Ray