Loud Pinging Noise in Baseboard Heat, Pilot Won't Stay On

[HayZee518]

if you can justify the cost of a liner it would help. a chimney cap would always help - keep rain out of the liner and breaks up any vorteses of air blowing around "up there" BTW how's the burner now?

[PGRich]

Help, we have a Williams wall furnace with similar problems. We tried all variations to get the pilot lit and here's what happened: 1) Pilot will not light with (millivolt) thermostat wires disconnected, 2) pilot won't light unless thermostat is calling for heat, 3) once lit, if thermostat is set below room temperature, burner does not turn off, 4) Each time burner ignites, but when it goes out so does the pilot light. We have replaced the thermostat and checked there is no ground on the wires to it. We also replaced the generator and this did not change the pilot situation. Thanks in advance.

[HayZee518]

Furnace with millivolt generator

A furnace with a millivolt generator or thermopile produces a millivolt voltage of between 250 to 750 millivolts. there are only two components that could be bad. 1) the thermopile 2) the pilot valve. The thermopile thermostat cannot be substituted with a 24 volt model. The millivolt thermostat cannot be used on a 24 volt system. The thermopile connects to the burner control with two wires one positive and one negative. you must observe the polarity or the pilot valve will not work. with a flame applied to the thermopile a dc voltage is generated which keeps the pilot valve magnet pulled in and allows the gas to burn at the pilot orifice. if the pilot flame goes out, the thermopile cannot generate a voltage. the pilot must be relit. the thermopile thermostat connects to the main valve and receives its signal from the thermopile. with the pilot lit and the pilot flame maintained you can jump out the thermostat wires to see if the main burners ignite. if the burners kick in jumped out but not with the thermostat wired in problem is the thermostat.

[BenderHeel]

Okay I'm back....which means that the heat is back off in my house!

After our last go-round, our plumber recommended that we get a chimney cap since he thought that was our problem -- the pilot light going out when the burners cycle off -- was caused by a large draft going up the chimney associated with the burners kicking off. So we got the chimney capped and cleaned, and no problems with the heat for the past month...until I got home from work yesterday.

Same problem as before: the pilot is out. I relight it. System kicks on because the room temp is below the set temp. After approximately 5 minutes, the boiler wants to cycle off, and when the burners go out, so does the pilot. Thus, no more cycling because no more pilot. The circulator continues to run. I relight pilot. System comes on, burners fire, etc. After 5 minutes, burners go out...and so does pilot. Repeat....

I've called the plumber back, but I'm at my wits end. This is our second plumber, and neither seem to be able to properly diagnose this problem. (The first said it was a drop in gas pressure associated with the gas provider. But it doesn't affect the hot water heater, which is 5 feet away, and plumber #2 says that plumber #1 is wrong.) I can't continue to dump more money into different issues since we already have dumped way too much already (new thermocouple, new gas valve, chimeny sweep and cap).

Does anyone have any guesses as to why the pilot would start to go out when the burners cycle off? And why the heck would it do it for a day or so and then not do it for a month? It seems like it's happening almost once every 4 weeks. HELP!

[BenderHeel]

Oh, and would an electronic ignition pilot system solve this problem? Plumber #2 recommended it in order to take the pilot out of the equation, but I don't know if it'll definitely solve the problem and he said it would be like $550 for the part and installation. THanks !