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conant47f's avatar
conant47f
Explorer
Oct 19, 2014

Help with furnace!

I have a 77 coachmen travel trailer with a suburban furnace. I can not get the pilot to light. The blower works and i have propane to the furnace. I checked the on/off valve going into it and it is clear also. Any ideas what the problem is?
Thanks in advance!

20 Replies

  • conant47f wrote:
    Well the way it sounds it's the gas valve. Can I even get parts for this anymore? Will any other parts switch out if not? Again thanks for everyone's help. You have helped me a ton!

    First see if you can get the main burner going.
    Report back if you do or do not. I am guessing that once the main burner is on for a few minutes anything that might be blocking the pilot light tube.

    You should be able to get a replacement but you will need the model and serial number.

    Get the main burner on if it will light
  • Well the way it sounds it's the gas valve. Can I even get parts for this anymore? Will any other parts switch out if not? Again thanks for everyone's help. You have helped me a ton!
  • The pilot is such a low pressure small flame just blowing at it with you lips will often clean it off good enough to solve the problem. We have also had good luck on the farm by banging on it (Gently) with a pair of pliers.
  • Thank you that explains a lot. Any idea how long I will have to hold the lighter on it to get the gas to come on?
  • Old-Biscuit wrote:
    Knob/button that you turn---push---hold at 'pilot' is what allows gas to flow thru pilot circuit (porting/tubing/orifice)

    Thermocouple is what has to get heated by pilot flame...when heated it allows main gas to flow and holds pilot flame circuit open.

    Bad thermocouple......no main flame (and pilot flame will not stay lit)but it doesn't stop pilot flame from lighting while you hold knob/button down.

    With knob/button down......no pilot........pilot tube/orifice is probably plugged.

    That is assuming you can get main flame to light off by heating thermocouple with a BBQ lighter and then lighting main flame when gas flows.

    IF you can't do that....then gas control (gas valve is bad--have to replace)

    Exactly
  • Knob/button that you turn---push---hold at 'pilot' is what allows gas to flow thru pilot circuit (porting/tubing/orifice)

    Thermocouple is what has to get heated by pilot flame...when heated it allows main gas to flow and holds pilot flame circuit open.

    Bad thermocouple......no main flame (and pilot flame will not stay lit)but it doesn't stop pilot flame from lighting while you hold knob/button down.

    With knob/button down......no pilot........pilot tube/orifice is probably plugged.

    That is assuming you can get main flame to light off by heating thermocouple with a BBQ lighter and then lighting main flame when gas flows.

    IF you can't do that....then gas control (gas valve is bad--have to replace)
  • Will propane still get to the pilot light and main burner if the thermocouplar is bad? Or is that how it knows to turn the propane on since these don't have circuit boards
  • I'm sure you have a pilot light. Often the thermocouple on these goes bad. That's the tube in the pilot flame. Simple to change out and not very expensive.
  • No idea, but can you carefully take a torch or one of those propane lighters and heat the thermocouple until gas starts to flow and the main burner ignites?
    If the main burner ignites let it run for a while and then try the pilot. If no luck then the gas tube to the pilot is probably plugged check for spider webs etc