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