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Gas, Steam, Intermittent ignition operates erratically...

SteamoSteamo Member Posts: 4
Steam Boiler - Dunkirk Radiator Corp. M-PS52, S-52820093, 124,000.Btu/hr
Intermittent Pilot Module S86G
Honeywell gas valve M?
McDonnell-Miller water level SO812
PressureTrol Honeywell PA404 10092 (8246)
Johnson Transformer Y65AJ1, 24V, 40VA

Pressure Trol High set at 0.5 PSI

Boiler does not cycle overnight 7:00am Tstat reads 58F calling for 62F. It seems to be in Lockout and when Reset starts the cycle. Sometimes the gas valve "clicks" on and lights in 5 seconds, sometimes as long as 90 and sometimes not at all.
I suspect the gas valve.


  • delta Tdelta T Member Posts: 809
    Could just be the flame sensor not rectifying the flame signal back to the S86G controller. If you can see the pilot lit and the spark continues for more than a second or two, I would blame the flame rod and/or S86G
  • SteamoSteamo Member Posts: 4
    Thanks ^T,
    The pilot flame doesn't always come on right away and I believe that's what's causing it to time out.
    When the pilot is lit, sometimes with one of those BBQ lighters, the gas valve opens immediately.
  • JUGHNEJUGHNE Member Posts: 6,784
    I would clean the pilot & flame rod (stainless steel wool) and pull and reset all push on connections. Loosen and reset any screws for ground wires. Then consider the S86G and maybe the gas valve.
  • SteamoSteamo Member Posts: 4
    The ignitor seems to only come on for about 5 seconds, so that the pilot gas has not reached it and doesn't ignite, the ignitor keeps making the zzzzzzzzzzzzzz noise but I can't see any spark after the 5 seconds, so it doesn't light.

    S86 problem?
  • unclejohnunclejohn Member Posts: 1,525
    Like jughne said, pull the pilot and clean it. I use nitrogen and blast that through the pilot tube. Then clean the flame rod and igniter rod. Put it all back together and it should work. If it doesn't then you can change the control.
  • Charlie from wmassCharlie from wmass Member Posts: 4,123
    Maybe this is not a diy project? I think you need a pro to fix this. Jmho.
    Cost is what you spend , value is what you get.

    cell # 413-841-6726
  • SteamoSteamo Member Posts: 4
    Hate to admit it but I saw that the ignitor wire was grounding out on one of the burners. Little piece of electrical tape did it. Thanks, Steamo!
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