Furnace problems

[riden2low]

I have been beating my brains out over this furnace. This is in a 2017 Vibe trailer. You turn on the furnace and nothing happens. Pulled the furnace out, tested with a extra battery and the blower fires up and the igniter clicks. Put the furnace back in and it worked for about 5 minutes and nothing. I do have a new circuit board for it but trying to see if I can locate the problem first. Now checking the wiring it has the white and solid yellow together and the red from the furnace going to the white and yellow stripe wire. So I thought I would check the converter. What has me puzzled is the yellow and yellow stripe white wire are mounted on the same post in the converter. In the picture , the furnace fuse is the blue one in between the red fuses. So is this normal?

 

[Buly]

Looks like they run out of free fused terminals and connected two wires to the same fuse. You must find what each wire feeds to see if 15A fuse is adequate. One wire per fuse is the right way to do it.

 

[Gronk]

Do you have 12v+ and 12v- at the control board? Also, what happens if you jumper the thermostat wires?

 

[riden2low]

Do you have 12v+ and 12v- at the control board? Also, what happens if you jumper the thermostat

 

[riden2low]

Control board? On the furnace it’s self?

 

[Gronk]

Control board? On the furnace it’s self?

Yessir, you need to have power to the control board. Does your thermostat have a touch screen that you can control the A/C, fan, and furnace? Does the fan and A/C work?

 

[riden2low]

Yes the A/C works great, the thermostat is a Dometic go from auto to low and high works too. Just when we turn the furnace nothing happens. When I pull the furnace “ twice now” and bench test it , hooking up to and battery touch the two small furnace wires and the fan comes and you hear the ignition trying to ignite. It’s not bad pulling furnace but have crawl in a storage area to get to it.

 

[riden2low]

Well this is what did. Crawled into the compartment where the furnace is and took the thermostat wires and connected them together. The furnace fan came and the igniter fired up the furnace. So I’m thinking of new thermostat ???? At least get an updated one.

 

[LSG]

Pretty common fail rates on this unit make sure you match up the I’d numbers under the cover there’s different types of thermostats

 

[KR1973]

The control boards are usually the issue. They are old technology and are very fragile which causes intermittent failures until it quits completely. I've replaced several. I would change the control board if it were mine before I tried something else. I've also gotten bad control boards new so beware of that possibility. IMO the board and the thermocouple would fail more often than the thermostat you have

 

[Gronk]

That thermostat is a known problem child and an update for it would be a good thing. Up by the A/C behind the cover is a box that is about 4" square and 2" high. That is where all the thermostat wires (3 labeled 12+, 12-, Comm at thermostat) go. An updated t'stat would probably come with a new box, but you most likely won't need it. I just swapped this t'stat and everything worked much better. Easy swap too.

 

[riden2low]

That thermostat is a known problem child and an update for it would be a good thing. Up by the A/C behind the cover is a box that is about 4" square and 2" high. That is where all the thermostat wires (3 labeled 12+, 12-, Comm at thermostat) go. An updated t'stat would probably come with a new box, but you most likely won't need it. I just swapped this t'stat and everything worked much better. Easy swap too.

Ordered the same one. Even tho it will function the same , it lights up for a few seconds to see what temp you’re setting. The one in there now is you have to look close or turn on a light to see the settings. Thanks for the info on the A /C. I will check that out. Might a loose connection in there.

 

[riden2low]

That thermostat is a known problem child and an update for it would be a good thing. Up by the A/C behind the cover is a box that is about 4" square and 2" high. That is where all the thermostat wires (3 labeled 12+, 12-, Comm at thermostat) go. An updated t'stat would probably come with a new box, but you most likely won't need it. I just swapped this t'stat and everything worked much better. Easy swap too.

Ok I got the furnace going. You said something about a box for the controls of the A/C and furnace. Well after a week of camping I decided to clean the A/C's filter. I saw the box that you were referring to. I seen the wires for the thermostat. I moved them around and the wires fell out of the connectors. I thought "what?" They would slip in and out . So I found the problem. Put on new connectors and made sure they were tight. Hook the wires up and the Furnace came on with no problem. Thanks guys for all of the help. Got a happy camper here.

 

[Gronk]

Thanks for coming back to let us know what the fix was! Nice when it isn't expensive or difficult.