Forum Discussion

mikehoss's avatar
mikehoss
Explorer
May 10, 2016

Furnace is alway running

We have a 2004 Starcraft Aruba that has been good for us for the past few years. This year, when we got it out of winter storage, the furnace kicks in when we have it plugged in. Regardless of the thermostat reading... even if we have the air conditioner on, the furnace keeps running! I even disconnected the furnace wire on the thermostat... no change.

We don't need the furnace this time of year, so I removed the fuse marked "Furnace" and there it stopped! But our fridge happens to be on the same circuit.

I read in other forums that this would be with a bad circuit board or power going to the furnace. We don't take our TT out when it cold so even having the furnace on it's a big deal for us. Anyway I've tried to figure out where I would even start and I'm coming up with where to look. I took off the outside panel behind the fridge and it looks like this:
http://imgur.com/vq2a5Tw

The cord that is plugged in on the right is for the stove (I think ) and has power when the fuse is removed. How would one get to the board to look at it? Or does anyone else have any (cheaper) ideas than a new circuit board in the furnace?
  • Almot's avatar
    Almot
    Explorer III
    May 10, 2016
    Tstat, switches and furnace wiring are messed up somehow.

    The photo is for fridge.

    "Plugged in" what - shore power? 120V -> converter works -> 12V to the furnace.

    Are batteries also connected?
  • mkirsch's avatar
    mkirsch
    Nomad II
    May 10, 2016
    Do you mean plugged in on the LEFT? I see nothing but insulation on the right.

    If so, that is 120VAC, and is only powered when you are connected to shore power. Fuses do not have an effect on 120VAC power. Circuit breakers (the flip switches near the fuses) control the 120VAC current.

    Your furnace is entirely 12V and operates off battery power.

    Lift the front panel off your furnace, and there should be a small switch on the front. For now, you can just turn it off there and put the fuse back in so your fridge works.

    The furnace cannot be accessed from the outside. It must be pulled out of the cabinet to be serviced. You may want to have a professional tackle it if you want the furnace to be functional. Otherwise you can just leave it since you don't use it anyway.
  • DownTheAvenue's avatar
    DownTheAvenue
    Explorer
    May 10, 2016
    mikehoss wrote:

    The cord that is plugged in on the right is for the stove (I think ) and has power when the fuse is removed.


    That cord plugged in is for the refrigerator.
  • jetcare's avatar
    jetcare
    Explorer
    May 10, 2016
    FYI. The Dometic refrigerator in the picture has a recall that installs a fire sensor and flue sensor. It has not been done. It is still free of charge. I suggest you get it done soon.
  • enblethen's avatar
    enblethen
    Nomad
    May 10, 2016
    The photo is the back of the refer, not the furnace.
    Pop the cover off the thermostat. There should be two wires on a standard furnace thermostat. Disconnect one of them. Test to see if it runs. If it does not it is a bad thermostat.
    If it runs locate the furnace access panel, inside the coach. Find make, model and post that information.
    While there look for the thermostat wires. Should be blue in some makes. Disconnect one there and see if it runs.
    Depending on model and version, there could be a time delay relay. It could be stuck.
  • mikehoss's avatar
    mikehoss
    Explorer
    May 10, 2016
    Ranger Smith wrote:
    I would look for a chewed wire somewhere. Maybe a mouse got to it. Did you remove the tstat wire at the furnace???


    I did remove the tstat wire from the tstat, not from the furnace itself.

    And mice nibbles may make sense.. . we saw more signs of them this year than ever. Not bad, mind you, but my wife left a tupperware of dog food in a drawer and we saw a lot of droppings there (but they didn't get into the container, thankfully).
  • Ranger_Smith's avatar
    Ranger_Smith
    Explorer
    May 10, 2016
    I would look for a chewed wire somewhere. Maybe a mouse got to it. Did you remove the tstat wire at the furnace???

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