Furnace trouble?

[Ryanb-72]

Hi all. We recently got back from a trip up to CO. Weather got cold enough for us Texans at night to warrant running the furnace for a bit. We were camping at an altitude of about 8500 feet. off grid just batteries. Refrigerator, water heater, all working fine.
When I went to turn on the furnace the first morning to break the chill you could hear the click, click, and then the propane ignited. The furnace ran for all of maybe 10 seconds and then you could hear the flame go out and only the fan run. The igniter would kick back on and the process would repeat.
I hunted around and thought and thought, Finally deciding to take the outside cover off to see what I could find. In doing so I somehow discovered that taking off the cover provided enough air that the furnace stayed lit. That was until the last morning when the air seemed exceptionally dense and it just wouldn't light. Of course it was the coldest morning at 39 in the camper.
So the next day we moved to a lower campground at 7500 feet as part of our plans and the furnace then fired up without any issue. I have used RV furnaces at elevation before, 9000ft comes to mind, without any issue. Is there something that can be adjusted that I haven't found to keep the furnace lit at elevation?
Thanks,
Ryan

[SRS]

Originally Posted by Ryanb-72

Hi all. We recently got back from a trip up to CO. Weather got cold enough for us Texans at night to warrant running the furnace for a bit. We were camping at an altitude of about 8500 feet. off grid just batteries. Refrigerator, water heater, all working fine.
When I went to turn on the furnace the first morning to break the chill you could hear the click, click, and then the propane ignited. The furnace ran for all of maybe 10 seconds and then you could hear the flame go out and only the fan run. The igniter would kick back on and the process would repeat.
I hunted around and thought and thought, Finally deciding to take the outside cover off to see what I could find. In doing so I somehow discovered that taking off the cover provided enough air that the furnace stayed lit. That was until the last morning when the air seemed exceptionally dense and it just wouldn't light. Of course it was the coldest morning at 39 in the camper.
So the next day we moved to a lower campground at 7500 feet as part of our plans and the furnace then fired up without any issue. I have used RV furnaces at elevation before, 9000ft comes to mind, without any issue. Is there something that can be adjusted that I haven't found to keep the furnace lit at elevation?
Thanks,
Ryan

It's probably not related to elevation. You might want to search this site for information on the "sail switch." They can get dirty with lint and hair. Some have found bending the switch so it gets catches more air from the fan works. Another person found removing the dryer like duct that's attached to the interior grill works. There are lots of video's related to removing, cleaning, and replacing the sail switch. ETI has a good one.



I haven't yet experienced the problem on my 2022 17A yet but I've found my water heater prefers slightly moister air particularly at elevation. When it sputters I open the cover. My furnace has worked perfectly at 10,000 ft., but I also carry a spare sail switch and control board just in case.



Good luck

[mvassallo]

Based on your post this link may be of help. An RV tech in Cheyenne said the one of the main reasons for heater problems is air flow.

https://www.escapeforum.org/forums/f...ues-19603.html

You can also find this under my user name of: mvassallo

Mike