This old gal has been burning regularly since we bought her in 2010.
Initially, the temperature-sensing bulb was broken, so I disassembled the whole gas valve and disabled that feature. I internally set it for half-way, so I can turn the temperature knob and turn on or off the main burner as I see fit. I also had it completely out of the camper so I could give it a thorough check for rust-through and make sure there were no leaks
that could kill us.
We don't use it very often, and sometimes, we don't use it at all for a season, but every spring I vacuum and bang on it to keep it clean, then it gets a nice long run to come up to temperature and make sure everything is fine.
This spring I didn't notice, but it must have been burning a little weakly.
Then, last week, we camped in NH and it got to like 40F the first night and when I lit the main burner, it didn't light
. :-( I would get an occasional tiny "Fluff" of flame and then nothing for 2-3 seconds, then a tiny foof of flame again. We ran the pilot light
that evening to keep the inside barely acceptable. We sleep in a tent, so I wasn't worried about overnight because we KNEW it would be cold.
The next day, I was (barely) able to get the main gas line disconnected and the burner out and disassembled, and I could see through the main orifice, but it was not round. So I stripped a bit of stranded copper wire (always keep tools dedicated to the camper IN the camper!) and I was able to get whatever was in there cleared out and after reassemble/soapy-water-ckecking and gas-power on it burned better than ever before. Nice strong flame, ignites immediately and produces way more heat than previous seasons.
So, I guess it was getting progressively more clogged over the years and eventually didn't let enough gas through to maintain a flame.
Lesson learned. What lesson? Have tools and experience maintaining your old crappy stuff if you're going to camp.
I do love this old furnace
and I hope I never have to replace it with a modern powered-fan version.
Bear Brook State Park, NH.