Gas Furnace Whoa's

[Wellplayedsir]

I read most of the posts on this subject still a no go blower coming on fo 20 to 30 seconds then shuts off, changed the sail switch same thing still no heat is there anything else I could try without going to far down the rabbit hole.

2021 montana 3781

[Ahdmeyer]

i believe there are numerous posts about this self setting fuse. worth a try checking it out if you do have this resetting fuse. my son has a keystone cougar and had this problem, the dealer gave him a regular fuse to replace it.

The black furnace fuse is a self resetting relay as stated in previous reply. You can search this site and find multiple post on the problem you are having. Solution is to replace with a standard 15amp fuse.
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[Gonefishing]

Originally Posted by Wellplayedsir

I read most of the posts on this subject still a no go blower coming on fo 20 to 30 seconds then shuts off, changed the sail switch same thing still no heat is there anything else I could try without going to far down the rabbit hole.

2021 montana 3781

I been having same problems. You all ready changed the sail switch. Check the fuse if it is a black fuse change it out to a regular fuse. If that doesn’t work check the squirrel cage. Remove the sail switch turn the cage by hand looking for broken fins. Mine had several they replaced it. After replacing it, it now will run for 20-25 minutes.

Good luck I still don’t have heat. Have replaced sail switch, squirrel cage, converter and thermostat. I have talked with a keystone technician he said check the motor listen for any noise and see if it’s getting hot. If so then it is going bad. That is my next step. Seems the motor has to spin fast enough to keep the sail switch closed to keep the heat running.
Please keep us updated as to what you find out is the problem as I will do you the same. Have another technician coming out after the holidays.

[jsb5717]

I assume you have exterior access to your furnace? That makes troubleshooting a lot easier. I'm also assuming that you've checked the fuse by now and made sure you have a standard blue 15a fuse installed.

If you have a multimeter you might check the sail switch before and during operation to make sure that it's actually closing. If the squirrel cage fan has broken fins there might not be adequate air movement to close that switch...worth checking before digging deeper.

If it is closing but not attempting to spark then I would suspect the main control board.

[Bladescb]

We went through heating issues last year. It turned out to be the circuit board behind the panel that covers the heater on the outside. The circuit board was corroded on the edge of the circuit board causing the solder traces to make contact with each other. I tried cleaning it but it was to far gone. Ordered a new one and it was the fix, Heat working again. The electric fireplace in the front living room doesn't exactly heat a 40' trailer very well!

[Wellplayedsir]

Changed over the fuses "there were 2 so I changed both" and checked they ohms on the new switch that is good "so was they old one" local place can't make a service call for another week it has already been two.

[jsb5717]

Originally Posted by Wellplayedsir

Changed over the fuses "there were 2 so I changed both" and checked they ohms on the new switch that is good "so was they old one" local place can't make a service call for another week it has already been two.

I'm banking on the control board. You can get one on Amazon. If you have the manual for the furnace that came with your trailer you can go to the back where all the parts are listed. Find the model number of your furnace and you'll find the part number for your control board. Control boards will work on many different models so it should be easy to identify.

If you can I'd get the Dinosaur brand replacement board.

[Wellplayedsir]

control board showing up on saturday will follow up

dinasaur #Fan 50 plus pins $100 amazon

[rames14]

I am sure that you checked the igniter screw. On mine, we checked sail switch, had the new fuse in replaced board, valve and the tech was putting it back together when he found the igniter screw was stripped. Larger screw and it took off like a champ. The igniter screw is the ground for the system. I had Keystone look at it and also talked to Dometic. Out west, they all blame it on altitude. Simple screw that was never checked. Has not missed since. It only takes a second to check that screw.

[DutchmenSport]

You might have an excess amount of dust build up on the blower fan causing it to run slow, which will not allow enough air movement over the sail switch, thus causing the shut down.

Get a can of compressed air and blow everything around the fan and motor and make sure nothing is dragging it down. It takes only a tiny bit of collected dust, or a single hair to get would around and cause things to run slower. Blow everything out real good. It's a simple start that doesn't cost anything except some time and a can of compressed air. (or if you have an air compressor, use that... cost is then nothing).

[Wellplayedsir]

Hi thanks to all that have replied, actually there is a little opening where the sail switch is
and you can the blade, I had my wife turn the heat on while I stood in front of the furnace and could see the blade move. That area is vry clean and free from dust and debris.

[Wellplayedsir]

Is there a good youtube on how access or change the control board I could not find any. It's a Dometic

[jsb5717]

Originally Posted by Wellplayedsir

Is there a good youtube on how access or change the control board I could not find any. It's a Dometic

With exterior access it's actually very simple. Pull off the exterior access cover and you'll see the control board. It's easy to remove from its cradle. Then simply start transferring the various wired connections from the old to the new and put it all back together.

Make sure the switch is off (or disconnect all power to the trailer) before working on it. Then make sure it's all back on when you're finished.

Added: It's a good idea to take a few pictures of the current board as reference for how it's installed and where all the wires are connected BEFORE taking it all apart.

[Foldbak]

Originally Posted by Wellplayedsir

Is there a good youtube on how access or change the control board I could not find any. It's a Dometic

https://www.google.com/search?sca_es...niqYY-Ohc,st:0

[Wellplayedsir]

Thanks, my pc board is facing the front of the rv when I take the cover off, it has pins instead of screws so maybe that will help.

My furnace and fireplace both pooped out on me the same day while we are having a cold spell here in the Sunshine state.

Happy Newyears fellow MOG's

[Daryles]

I saw this very handy troubleshooting chart. It's pretty much a summary of the Furnace service manual troubleshooting chapter in the files section.

[MandK]

Originally Posted by Wellplayedsir

Thanks, my pc board is facing the front of the rv when I take the cover off, it has pins instead of screws so maybe that will help.

My furnace and fireplace both pooped out on me the same day while we are having a cold spell here in the Sunshine state.

Happy Newyears fellow MOG's

When I ordered the Dinosaur board it came with brass grommets in the mounting holes that act like feet for applications where it attaches horizontally to the furnace floor to hold it up off of any moisture that might get into that area. Don’t know if yours will be like that. In order for the plastic pins of the holder to fit through the holes, you have to carefully ream those grommets to remove the knurled part so you can push them out. I used an appropriate sized drill bit. Just an fyi that you may have to do that.

[jsb5717]

Originally Posted by MandK

When I ordered the Dinosaur board it came with brass grommets in the mounting holes that act like feet for applications where it attaches horizontally to the furnace floor to hold it up off of any moisture that might get into that area. In order for the plastic pins of the holder to fit through the holes, you have to carefully ream those grommets to remove the knurled part so you can push them out. I used an appropriate sized drill bit.

Yeah, same here. It's pretty easy, though, to pinch them out of the holes so it will fit.

[Kyle and Lisa]

Originally Posted by Wellplayedsir

I read most of the posts on this subject still a no go blower coming on fo 20 to 30 seconds then shuts off, changed the sail switch same thing still no heat is there anything else I could try without going to far down the rabbit hole.

2021 montana 3781

Always check the exhaust pipe first with a flashlight for dirt dobber nest, disassembled. If there is not enough airflow it will run and shut off, been there done that more than once.

[Wellplayedsir]

A Dinosaur fixed it, heat is not over rated thanks fellow MOA's.