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thetundrawolf's avatar
thetundrawolf
Explorer
Jan 10, 2020

Duo Therm 65900-001 sparking but not lighting?

Hi, I have an older trailer with a Duo Therm 65900-001 furnace, it's getting propane fine, and 120v, when I connect the thermostat wires the fan comes on, and it sparks, I hear the solenoids in the propane valve click on, and I see it sparking in the glass window, but it never ignites. Any ideas on why it's not igniting?
  • laknox's avatar
    laknox
    Nomad
    Jan 10, 2020
    thetundrawolf wrote:
    Hi, I have an older trailer with a Duo Therm 65900-001 furnace, it's getting propane fine, and 120v, when I connect the thermostat wires the fan comes on, and it sparks, I hear the solenoids in the propane valve click on, and I see it sparking in the glass window, but it never ignites. Any ideas on why it's not igniting?


    Might be a bad sail switch.

    Lyle
  • Roger10378's avatar
    Roger10378
    Explorer II
    Jan 10, 2020
    Probably a spider web in the burner tube. You wouldn't hear the gas valve if the sail switch was not working.
  • StirCrazy's avatar
    StirCrazy
    Moderator
    Jan 10, 2020
    i had the same issue with my camperi just bought. a good air gun and 10 min of blowing out the combustion side, it now works perfectly.

    Steve
  • Chris_Bryant's avatar
    Chris_Bryant
    Explorer II
    Jan 10, 2020
    That’s an old furnace, most likely needs cleaning. If it is sparking the sail and limit switches are good.

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