Forum Discussion

Dog_Trainer's avatar
Dog_Trainer
Explorer
Oct 09, 2015

Furnace lighting problem

Our new 2015 TT has a suburban furnace. When the propane has been shut off and re lighted it may take 5 or 6 cycles for the furnace to ignite. I expect that as the air must get out of the system after the line has been without propane. On past trips the furnace would relight each time with no problem after the line was charged. On the trip we are now on the furnace has been hard to start most of the time even though the line is charged and the propane left on. All other appliances such as the Refer and the stove light immediately.
One thing I have done differently this trip is I have left the water heater switch off and have been running the water heater on electric only. The Water heater is down line from the furnace and I am wondering if I am losing line pressure there. Or I imagine it could be a loose fitting. I will check the fittings tomorrow and have the furnace shut off as we use an electric fireplace. There is no smell of propane outside or inside except I get a little whiff when the furnace tries to cycle. As always comments and suggestions are most welcomed.
Seeking Advice
  • rwjejits's avatar
    rwjejits
    Explorer
    Oct 10, 2015
    Chris Bryant wrote:
    Old-Biscuit wrote:

    W/O any propane use (WH/Fridge) etc. the system has no demand and no flow so when you go to operate furnace it not lighting off on first attempt doesn't mean there is any problem.


    I still disagree with this- the regulator maintains a pressure of 11" w.c.- there will always be LP at the furnace at that pressure, unless the lp has been shut off. The furnace gas valve opens, there is lp right there at the correct pressure. If the furnace isn't igniting right away, there is a problem- likely the misaligned igniter, or bad (kinked)lp piping. Regardless, it should be addressed under warranty.


    Makes sense to me.
  • Chris_Bryant's avatar
    Chris_Bryant
    Explorer II
    Oct 09, 2015
    Old-Biscuit wrote:

    W/O any propane use (WH/Fridge) etc. the system has no demand and no flow so when you go to operate furnace it not lighting off on first attempt doesn't mean there is any problem.


    I still disagree with this- the regulator maintains a pressure of 11" w.c.- there will always be LP at the furnace at that pressure, unless the lp has been shut off. The furnace gas valve opens, there is lp right there at the correct pressure. If the furnace isn't igniting right away, there is a problem- likely the misaligned igniter, or bad (kinked)lp piping. Regardless, it should be addressed under warranty.
  • Old-Biscuit's avatar
    Old-Biscuit
    Explorer III
    Oct 09, 2015
    Dog Trainer wrote:
    Old Biscuit I concur with what you have stated. I also am running the Refer on Electric. I had not thought about the electrode that ignites having a mis adjustment but there may be something going on there I do smell that whiff of propane from the furnace vent even when the furnace did not light.
    Last night after I posted this topic, I shut off the electric for the WH and turned on the gas button. This morning when I got up I turned the furnace on and it fired right up. I think I can leave both the electric and the propane turned on at the same time for the WH nothing in the manual says otherwise.


    YES you can use electric & propane at same time on water heater....fastest recovery rate that way.

    W/O any propane use (WH/Fridge) etc. the system has no demand and no flow so when you go to operate furnace it not lighting off on first attempt doesn't mean there is any problem.
  • Dog_Trainer's avatar
    Dog_Trainer
    Explorer
    Oct 09, 2015
    Old Biscuit I concur with what you have stated. I also am running the Refer on Electric. I had not thought about the electrode that ignites having a mis adjustment but there may be something going on there I do smell that whiff of propane from the furnace vent even when the furnace did not light.
    Last night after I posted this topic, I shut off the electric for the WH and turned on the gas button. This morning when I got up I turned the furnace on and it fired right up. I think I can leave both the electric and the propane turned on at the same time for the WH nothing in the manual says otherwise.
  • Chris_Bryant's avatar
    Chris_Bryant
    Explorer II
    Oct 09, 2015
    I agree- don't mess with it, take it in for service (or add it to the list). It does sound like a problem that will require removal of the furnace.
  • Old-Biscuit's avatar
    Old-Biscuit
    Explorer III
    Oct 09, 2015
    Are you running the fridge on propane or electric like the water heater?

    W/O a demand on propane system the regulator is basically closed until a demand for propane is called for an a flow established. Remember system pressure is only 0.4 psi
    IF water heater gas valve was leaking thru (you would smell propane at WH) or of a fitting was leaking then there would be a demand on regulator and line would have flow until you ran out of propane.


    Smelling a whiff of propane when furnace first lights off is not unusual-----gas valve opens for 6-8 seconds at same time spark electrode gets energized. BUT if you can smell that whiff then main flame should light off
    Sounds like spark electrode is slightly out of position (S/B centered over burner slots) or gap too wide (S/B 1/8")
  • Ava's avatar
    Ava
    Explorer
    Oct 09, 2015
    A lot of times people say to turn stove top burners on for few minutes then try the other gas appliances when there is a problem. Has worked for me in the past. Good luck

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