RV furnace troubles

Discussion in 'Heating / Cooling Systems' started by SgtRon, Nov 17, 2018.

  1. SgtRon

    SgtRon Member

    Messages:
    53
    Likes Received:
    36
    Joined:
    Jun 7, 2017
    Location:
    Florida
    New question: Our pup has a Suburban LP heater that I tried for the first time this morning, only blowing cold air. I watched the troubleshooting video, it looks like there are no consumer serviceable parts. I've turned on the LP gas, I moved the thermostat up and heard the fan turn on. I ran it for about 10 minutes, the air never warmed up. Does anyone have any suggestions, or should I just take it to a RV service center?
     
  2. Martlee

    Martlee New Member

    Messages:
    7
    Likes Received:
    9
    Joined:
    Aug 15, 2016
    You need a strong battery to ignite the furnace. Have you tried it on AC. Plugged into an outlet that is.
     
  3. BikeNFish

    BikeNFish Well-Known Member

    Messages:
    2,460
    Likes Received:
    1,441
    Joined:
    Apr 24, 2017
    Location:
    Maplewood, MN
    Are you getting gas to your furnace? Light your stove to make sure there is gas flow.
     
    Sjm9911 likes this.
  4. SgtRon

    SgtRon Member

    Messages:
    53
    Likes Received:
    36
    Joined:
    Jun 7, 2017
    Location:
    Florida
    Gas is fine, stove lit, trailer is plugged into 110vac., not sure if the fan velocity (sail) switch is functional.
     
  5. PopUpSteve

    PopUpSteve Administrator

    Messages:
    18,379
    Likes Received:
    1,273
    Joined:
    Dec 22, 2002
    Location:
    Malvern, PA
    Could be a clogged gas line. Spiders love making nests in the gas lines right at the injector.
     
  6. joet

    joet Well-Known Member

    Messages:
    4,134
    Likes Received:
    714
    Joined:
    Mar 16, 2011
    Location:
    Elkins WV area
    You can always crack the gas line to check for flow
     
  7. p

    p Active Member

    Messages:
    489
    Likes Received:
    98
    Joined:
    Jun 9, 2014
    My furnace would not light one night. Tried for hours. It would light for a second then go out. It was like it needed air.

    I realized the steel wool I stuck in the air vent to keep the mice out was still there. Pulled it our...works.

    Several hours of my life never to get back.
     
  8. generok

    generok Well-Known Member

    Messages:
    2,370
    Likes Received:
    516
    Joined:
    Feb 7, 2013
    Location:
    Anchorage, AK
    So, are you hearing the igniter spark? If you are, you likely have a LP flow issue. Either the unit isn't getting gas, or your furnace regulator/valve isn't working correctly. If you don't, you have an issue with the igniter circuit.
     
  9. SgtRon

    SgtRon Member

    Messages:
    53
    Likes Received:
    36
    Joined:
    Jun 7, 2017
    Location:
    Florida
    I hear a " click" which i assume is the igniter attempting to light
     
  10. SgtRon

    SgtRon Member

    Messages:
    53
    Likes Received:
    36
    Joined:
    Jun 7, 2017
    Location:
    Florida
    I'm not comfortable working with LP, I'll leave that to a pro.
     
  11. generok

    generok Well-Known Member

    Messages:
    2,370
    Likes Received:
    516
    Joined:
    Feb 7, 2013
    Location:
    Anchorage, AK
    Maybe. There should be a couple of clicks. Once the fan is running, and the time delay expires, the LP control valve has to open, probably making a click. Then, the igniter should begin to fire. Atwoods make a double click, three time, and then take a break if they don't light (at least all the furnaces I've owned have that pattern).

    The big question is, where is your furnace in the cycle:

    1. Fan turns on (indicating the t-stat is closing calling for heat)
    2. LP control valve opens (indicating the sail switch and time delay relays are working)
    3. Igniter sparks
    4. Burner lights (indicating LP is flowing and igniter works)
    5. Burner STAYS lit (indicating the thermocouple works)
    6. Burner and fan goes off (inidicating t-stat is opening at set temp)

    Sounds like all you're sure of is #1. It's fairly important to know if you have a control valve issue, or if you have an igniter issue. The latter could be a motherboard issue, the former, an electromechanical issue at the valve.

    It sounds like you're uncomfortable with tinkering with the LP side of the house, so it's probably best to hand it to a service center and say "fix this" and they will, and you will have heat once again. Otherwise, you have to troubleshoot your way through the components.

    Best of luck!
     
    Fless likes this.
  12. William Freeman

    William Freeman Active Member

    Messages:
    163
    Likes Received:
    93
    Joined:
    May 5, 2018
    Location:
    Richburg SC
    My fan was coming on but it wouldn't light - wouldn't even try to ignite. After reading a bunch of threads on here, I removed and touched the thermostat wires together and everything started as it should. Turns out the thermostat on/off switch contacts were misaligned. I played around with bending them a few times until it started working correctly.

    Now that I think about it, I meant to replace that thermostat (and relocate) with a digital one. I guess I'd better go ahead and order one so I can get that done before our trip at the end of the month!

    Edit: I went back and re read my thread when I was troubleshooting. I DIDN'T remove the wires, I just removed the cover and fiddled with the ON/OFF switch because it was stuck. When I did this, the contacts bent and weren't making contact when turned to the ON position. I pressed the contact down so that they made contact and held it there - started up normally. That's when I played around with bending the contact strip until it worked correctly.
     
    Last edited: Nov 18, 2018
  13. Fless

    Fless Active Member

    Messages:
    911
    Likes Received:
    176
    Joined:
    Aug 14, 2012
    Location:
    Colorado
    ^^^^ What @generok posted is great basic troubleshooting, step-by-step. It's great to see such well-thought-out info on the forum.
    _
     
    William Freeman likes this.
  14. Naps

    Naps New Member

    Messages:
    1
    Likes Received:
    0
    Joined:
    May 14, 2019
    Hi, my problem seems to lie between step#3 and Step#4. I have times where the furnace goes through it's 3 try's at lighting the burner ( I can hear the sparking occurring), but fails and goes into a soft lockout where the led blinks 3 times in a second. I believe I can hear the click of the gas valve opening before hand. The real confusing thing is that by cycling the heat on/off at the thermostat and retrying the furnace, it eventually lights. Once lit it stays running normally and shuts off once temperature is reached.

    The problem is intermittent and happens more than once during the night. Problem happens when hooked up to power so it's not a battery issue.

    I'm thinking it is a propane issue that only occurs at startup. Any suggestions on what to look at first would be greatly appreciated.

    Thanks!
     

Share This Page

  1. This site uses cookies to help personalise content, tailor your experience and to keep you logged in if you register.
    By continuing to use this site, you are consenting to our use of cookies.