Furnace won't light

[Shawbird]

Camping in the Rocky Mountains near Black Hawk, CO and the darn furnace won't light. The blower comes on and you hear it trying to ignite but it won't. Plenty of propane as the stove works, no wasps nests in the compartment, everything looks ok. Wondering about the house batteries? Coach only has 2900 miles on it. We used it in the past and it just about ran us out it worked so well. Gets down to the low 40's at night an a little heat would feel good! Looking for suggestions.

[16ACE27]

Spider webs near the igniter? Somebody turned the gas off at the furnace? The valve is a ball valve with a screwdriver head. The slot should be inline with the gas line.

[MiramarVA]

I have had the same issue with the furnace on my Miramar. It seems to be an intermittent problem because when I go to troubleshoot, it works fine. Have had the dealership look at it but they cannot recreate the fault.

[Blackjeepjk]

my last coach and current (thor hurricane 29m) have both had issues starting the propane water heater and propane furnace, water heater worse than furnace after storage periods in between trips. My remedy is to light the gas stove top burners, usually all 3 and let burn for approx 1 minute then while stove top still burning turn on the other appliance (water heater or furnace) they light immediately and the process doesn't need repeated until after another storage.

[SuperD]

I to have the same problem if the coach had been sitting for a while, takes time to purge air out of the lines.

[Hittntherooad]

There have been some issues with water getting into the furnace from a vent installed improperly in the access door. Seems the vents were pointed the wrong way letting water in. Check to see if your access door has a vent in it. I believe the new ones don't have a vent.

[tkempton81]

I'd been unable to get my furnace to consistently ignite (every once in a while it would turn). I read through the forums, pulled the gas valve, checked for spider webs, checked the gapping on the sparker, checked the sail switch, etc. After all this I began checking the voltage arriving at the board while it was calling for heat and realized that the voltage was fluctuating anywhere from 0-20v very erradically which led me to believe I had a short in the wire. I pulled the the panel off under the fridge and confirmed the connections were tight on that section, I found another connector underneath the kitchen sink and confirmed those connections were also tight. I then moved to the fuse box and verified that the fuse labeled "appliances" was in fact feeding power to the furnace. The fuse was in good shape and power leaving the fuse box appeared ok. I then decided to tighten down each screw in the power box, I tightened all of the connections for both 110v power as well as connections for the 12v power, while doing this I discovered the very large (maybe #6? white) wire lugs were never tightened down from the factory. I tightened those and all others in the box and the furnace has been operating flawlessly since. Hope this helps someone that was as stumped as I was.

[Metalman]

Years ago I had a problem with the furnace not working only at high elevations (8000 ft. or more). Since we had a generator and heat pumps I didn't diagnose or solve the problem. I wonder if there is some kine of subtle adjustment that needs to be made a higher elevations?

[frankgtx]

I’ve been told that at altitudes above 8000ft standard RV propane regulators act up. Not sure if that’s the case but we did have issues with our furnace in Flagstaff. Not once since.