Furnace Not Igniting at Altitude

[JFRINALDI]

Been through this a few times in the same State. Our sea level adjustments were set to starve the propane of oxygen. There is a tube with a screw to allow adjustment of the intake. We learned this from an AS tech at the dealer just outside Denver.

[Glenn T]

Originally Posted by kjloeffler

Just wanted to see if anyone has any ideas of how to get the furnace to ignite while we have it at home at 8100' in cold Colorado! Brand new, so it should be functional and should not need cleaning...

Whenever I turn on the propane tank valve after it's been closed a while, I have to "prime" the system - I turn on one cooktop burner and turn the manual igniter for a few moments until it lights. After that the furnace and refrigerator will fire up on the first try.

Glenn

[47WeeWind]

Because your stove, hot water tank and refrigerator all seem to work fine and ignite with the same propane (presumably at your present 8100' altitude) it does not seem to me your gas regulator needs any adjustment. Read closely the specifications for your furnace to determine if it is equipped with an oxygen depletion sensor. That is a safety device -- installed for your protection by those who dwell only at sea level -- which prevents appliances from operating when ambient oxygen is low. Unfortunately, it also prevents the appliance from operating at all above certain altitudes, which vary among manufacturers and devices, but seem generally to begin around 9000' above sea level.

I live in Denver, and when shopping for newer appliances for my vintage RVs I avoid buying any that have an oxygen deletion sensor because I want my appliances to operate at the high altitudes prevalent in Colorado.

If you furnace has an oxygen depletion sensor installed, that might be the cause of your problem. I don't know if they can be adjusted, but research that possibility if one is present. If your furnace does not have one installed, then you need not concern yourself about it and should continue to look for other reasons your furnace refuses to ignite. Maybe the air/fuel ratio needs to be adjusted; but then again with newer appliances perhaps that is controlled electronically and is incapable of being adjusted manually -- again for your safety . . . better frozen that dead.

Best wishes in getting your furnace to work. And Congratulations on your purchase and welcome to the wonderful world of Airstreams.

[TonyGuyer]

We had a similar problem with our new 2015 Classic two years ago. The furnace worked fine in the desert in Arizona where we live, but when we took it up to the mountains to 7000 feet or higher, the furnace would ignite and run for anywhere from 5 to 20 seconds and then shut off (duration was random). We took it back to the dealer where they first checked the pressure with a Manometer and made minor adjustments. We took it back to the mountains and had the same problem. We then took it back to the dealer, they replaced the regulator. Again, this did not affect the problem at high elevation. Finally, we took it back to the dealer a 3rd time. They dismantled the propane lines and found various debris in the propane lines (again, keep in mind this was also a brand new trailer). We took it back up to the mountains, and have never had a problem with the furnace since then. It has worked very reliably in elevations ranging from 1000 feet up to over 10,000 feet. The dealer indicated we were not the first new trailer in which they had seen this problem.

[kjloeffler]

The high elevation kit is a very simple piece that you can replace with four screws by yourself. It just has a larger baffle area to let more oxygen in. Even with that however, when we went to lower elevation the furnace still did not work. We took it to the local RV service center and they checked it out, it was actually the spark was too small or close and they had to adjust the spark. Since then it's worked perfectly at every elevation!