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jvowell1's avatar
jvowell1
Explorer
Jan 07, 2015

Atwood Furnance problem

I have a 1996 Damon Intruder I got this past summer. It has an Atwood furnance model 8535. It would not light so I pulled the burner and there was a dirt dabbers nest on the orfice. I thoroughly cleaned . I set the gaps correct on the ignighter and made sure the clicking was sparking. Clicks but no light. I bought a new dinosaur board and installed. Still no light. Hooked up a mannometer and checked gas pressure and it was at 9 inches so I replaced the regulator. Now I have 11 inches pressure. Still no light. Looking at it in frustration trying to think what to do next, I covered the exaust port while it was clicking and it lit! I let it run for awhile, turned the thermostat down, and it shut off normally. Turned the thermostat back up. It clicks no lit. I covered the exaust again and it fired up, any thoughts what might be happening?
  • Jfet's avatar
    Jfet
    Explorer
    Jan 07, 2015
    cruiseruser wrote:
    A well known rv store wanted also $162.00 for the same switch.


    The whole furnace doesn't cost much more than that!
  • cruiseruser's avatar
    cruiseruser
    Explorer
    Jan 07, 2015
    We had almost the exact same problem in a class C that my son owns. We did everything that you have completed, except for a new Dinosaur board. Check the sail switch. It has quite a lot to do with the air flow. After we changed his... we were golden.

    By the way, check prices. You can get an aftermarket switch under $50.00 online. A well known rv store wanted also $162.00 for the same switch.

    Good luck. Hope this helps.
  • enblethen's avatar
    enblethen
    Nomad
    Jan 07, 2015
    Most LP gas valves have two coils. Test each of the coils for resistance, they should be nearly the same.
    Does your other gas appliances work properly?
  • jvowell1's avatar
    jvowell1
    Explorer
    Jan 07, 2015
    Yes the orfice is cleaned I have cheked and rechecked. The ignightor is a fixed position and I adjusted the gap to the correct setting. I thought about the wire sparking else where so I pulled it out and it was sparking across the igniter. Is it possible the gas valve are not opening enough?
  • enblethen's avatar
    enblethen
    Nomad
    Jan 07, 2015
    Did you clean the orifice?
    Did you pull the burner out of the furnace and insure screen is clean?
  • Gripnriprod's avatar
    Gripnriprod
    Explorer
    Jan 07, 2015
    Could be the spark is happening somewhere besides at the igniter tip as in jumping from the wire or elsewhere.
  • kohldad's avatar
    kohldad
    Explorer III
    Jan 07, 2015
    Sounds like the igniter may not be in the correct location. By holding your hand over the exhaust, you are slowing the airflow down, letting the gas bubble build a little larger and reaching the igniter.

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