Furnace intermittent malfunction

[Traildad]

I have a 2015 Escape 19. It has intermittent furnace problems. It will run for a few minutes and shut off. Turn the thermostat down and back up and it will restart and run for a few minutes. Several times when left on all night we wake up in the morning with a warm trailer as though it is working properly. My furnace has to be pulled into the trailer to work on it so I don’t see an easy way to check the circuit board error codes. I just got done pulling the sail switch and couldn’t find anything obviously wrong with it. I have the one with bends in the sail. I read maybe some sails bind against the inside so I bent the end a little. I’m not sure what else I can do to troubleshoot it.

There is a switch that is labeled Off and Reset. What does it reset and should it be set to off or reset during normal operation?

[Eggscape]

First thing to check is that your battery voltage is high enough to keep the fan running. Sounds like there is enough for start up but maybe not to keep it running.

You can alway put in an outside hatch so that you can assess the furnace in the future. You can see how to do that here:
https://www.escapeforum.org/forums/f...tml#post284291

Good luck

[HABBERDABBER]

"You can alway put in an outside hatch so that you can assess the furnace in the future. You can see how to do that here:"
https://www.escapeforum.org/forums/f...tml#post284291

I've wanted to do this mod, but be aware that yours and mind are "classic" Escapes and the layout and details may be different than the mod and hatch location as described in the link.
I have acquired the hatch, but for other reasons haven't accomplished this task.

[Traildad]

Originally Posted by Eggscape

First thing to check is that your battery voltage is high enough to keep the fan running. Sounds like there is enough for start up but maybe not to keep it running.

You can alway put in an outside hatch so that you can assess the furnace in the future. You can see how to do that here:
https://www.escapeforum.org/forums/f...tml#post284291

Good luck

I’m bench testing it now while it’s still hooked to the trailer wires. The trailer is plugged into shore power so I assume it is getting proper voltage although my meter is reading under 12 volts.

[Ron in BC]

Originally Posted by Traildad

I’m bench testing it now while it’s still hooked to the trailer wires. The trailer is plugged into shore power so I assume it is getting proper voltage although my meter is reading under 12 volts.

That would seem like a red flag.

Ron

[climateguy]

Originally Posted by Traildad

I’m bench testing it now while it’s still hooked to the trailer wires. The trailer is plugged into shore power so I assume it is getting proper voltage although my meter is reading under 12 volts.

In my 2016 Escape 17B I assumed that when plugged into shore power that I must be getting shore power, until I realized in 2023 that there was no shore power getting into the trailer. There hadn't been a problem until 2023.

The problem was the connection between the outbound EMS terminal and the wire leading to the power converter. The wire had never been installed properly. It hadn't been stripped long enough, and only a short bit of bare wire had ever been inserted into the terminal of the EMS. After 7 years of working successfully, it failed to conduct any electricity at all. Slight movement of the wire caused by the trailer bouncing down the road over time working on this poor connection eventually took its toll. It was difficult to diagnose because I was assuming that connections made in the factory on a well made trailer like this would only very rarely if ever cause problems.

[Traildad]

The A/C works so I know it is getting shore power. I was watching a RV repair man troubleshooting a furnace and his meter was reading the same as mine and he didn’t mention it being a problem. My other thread on bench testing the furnace shows some other possibilities.

[UncleTim]

I would replace the sail switch. I am not convinced that a visual inspection will yield notification of lint caught in the switch, out of sight.

I had intermittent start up issues, usually cutting out at the 30 second mark. I changed the $35 sail switch and it behaves normally again. I could not see anything wrong with the switch when inspecting it. Changing it out is cheap insurance and if they both work, now you have a spare.

Just my approach.

[Traildad]

Originally Posted by UncleTim

I would replace the sail switch. I am not convinced that a visual inspection will yield notification of lint caught in the switch, out of sight.

I had intermittent start up issues, usually cutting out at the 30 second mark. I changed the $35 sail switch and it behaves normally again. I could not see anything wrong with the switch when inspecting it. Changing it out is cheap insurance and if they both work, now you have a spare.

Just my approach.

In my other thread I described the bench testing I did. My furnace lights up and runs normally for 3 minutes or so. The way the safety system is designed it can’t light unless the sail switch is working. When I test the voltage on the sail switch after it shuts down it shows the sail switch is good. Right now the bench testing points to an overheating condition or a faulty high limit switch. Check out the bench test thread, it has some interesting results. https://www.escapeforum.org/forums/f...tml#post453802

[UncleTim]

You make good points.

Thanks for showing your work.

[Traildad]

I think I fixed it. I replaced the over limit switch while it was apart but I think the real problem was the mis-installed sheet metal baffle. You can see photos in the bench testing thread. It was blocking the airflow and causing it to actually overheat so the over limit switch was doing its job and shutting it off. There is a small angled piece of sheet metal at the top and the problem piece at the bottom. I think their job is to cause the air flow to circulate as it moves through the heat exchanger section so there aren’t any dead spots. Whoever assembled my furnace must have been having a bad day. I’m guessing the reason the problem seemed intermittent was when the weather was cold enough the furnace could run longer without overheating. I’ll put it back together and the real test will be when the weather cools down this winter. Thanks for the help and suggestions.

[Traildad]

I reinstalled it in the trailer and it looks to be working correctly. Keeping my fingers crossed.