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Cosmogas boiler question

bigals1 Member Posts: 2
I am a retired Master Plumber trying to help an elderly couple with a Cosmogas Axia boiler. Unit will try to fire gas valve opens and shuts down right away. After trial and error I pulled spark wire off where connects to probe, held it with a gap and turned on boiler, it fired. It ran for 2 weeks, did the gap thing again and off she goes. This has happened several times. Seems like breaking contact allows spark generator to send power. Any help would be greatly appreciated.


  • kcopp
    kcopp Member Posts: 4,431
    Axia is a pretty simple unit. It is generally pretty reliable. The Honeywell controller only allows 1 trial for ignition and then it locks out....not cool.

    Make sure the electrodes are in good shape. Over time they will bend.
    The board may need replacing.
    W/ the board comes a new harness that goes from the board to the gas valve (black colored) replace the red version...they did have some issues w/ that.
    That will get it back running.
  • bigals1
    bigals1 Member Posts: 2
    Has new electrodes, but it seems like the signal for spark is being sent to to the electrodes, but something is stopping it from getting though if that makes sense. If you still think it is the board I will try, just making sure. Thanks
  • Tom_133
    Tom_133 Member Posts: 884
    This may not be what's keeping you from firing, but with the axia I have found that it builds a serious amount of junk on top of the heat exchanger. In doing so it will snuff combustion air. I would at least pull the top of the unit off and clean it with a soot vac or a shop vac with good filtration. Then see what you have.
    Montpelier Vt