I am working on an original steam heat boiler. It is a min 250k BTU Max 500k BTU Roberts Gordon model "84-z Nat" gas burner I'm dealing with now. I know it's pretty old, probably converted from coal in the 40's or 50's. I got the boiler working 5 years ago and it's been working great. Now I have a problem with it turning on and off about every 5 seconds. Troubleshooting lead me to think the pilot light isn't right and is turning off the solenoid when it gets hot. I'm at a loss to figure this out, and would like to get it running smoothly. What are my options? Would it be better to bring it up to code and install a new pilot light, meter, shutoff or just replace the part that is malfunctioning? This house will eventually be made into a b&b, so codes may be more important.
Do you have a diaphragm in the gas valve/solenoid? I had a similar problem several years ago and the diaphragm in the solenoid would not hold pressure. It would open, leak internally and close. Just a thought.
It's definitely the pilot safety switch (or whatever correct term it is) because it works perfectly if I have only the thermostat connected to the valve solenoid. With the wires going to the pilot, it will turn off and on.
Pilot burner flame when the main burner lites. Does it pull away from the bi metal sensor, or does the pilot flame diminish in anyway? It may just need a good cleaning of the pilot. Do not use any thing to poke into the pilot orifice. Use air pressure to clean orifice