I have a vintage Lenox (1930's) furnace that that needs work. Current problem is the safety relay won't stay latched. I replaced the thermocouple, hoping for a simple fix. I think the vibration of fan starting and stopping causes the relay to drop out. This is an old system where the safety relay only cuts current to the main gas valve if the pilot goes out. Should I replace just the relay (and where can I find one) or should I retrofit with a modern gas control valve? Background: fire box - fine, limit/blower switch - fine, blower - fine, would like to use a modern thermostat and there is easy acces to all in place wires and pipes. I have no qualms about working with gas or electric systems, just don't know about the variables or problems in retrofitting.
If you lived in my area, I have got about 3 of those antique pilot safetys I would love to get off my shelf. I have not sold one of these things for 10 years. And in my community they have gotten utility concient. We are not duing any work on anything under 80 percent. Good for us and the environment. What we would do in your case if you wanted to repair is to remove all the old gas train and bring it up to date with a redundant gas valve. Let me know if you need more assistance.