It's been a bad Friday/Saturday. Friday night my nearly new furnace quit heating. Got the guy out, and he thought that it might be low propane pressure -- I was not real enthused about this because other stuff was working.

Anyway, I managed to keep marginally warm with my woodburner ( temp went to -15F outside -- I never went below 50). And, the furnace guy came back on Saturday and solved the problem with the help of the propane guy.

Was not really the pressure -- there was soot blocking the chamber between the chimney exhaust fan and the flame. This caused the flame to drift back somewhat and trip the overtemp switch -- which kept the whole mess from blowing up!

During the course of all this I learned that the propane inlet pressure was 9" -- and it was supposed to be 11". However, I also learned that the internal furnace regulator ( now replaced ) further cut this down to 5" - not supposed to do that.

I'm thinking that the internal regulator failed sometime after the furnace was installed in November. I think that this really low pressure caused the flame to generate soot and ultimately clog the system. I really don't know a lot about propane combustion, but this seems reasonable to me.

I'm wondering if anybody has any opinions on the cause. I have my theory, but as noted, I'm far from an expert.

Thanks,

ford2go

 

I only use propane heaters (old style using clays). But used to use old propane powered Servals fridges while living on a mining claim. You had to keep an eye on any soot buildup and clean the pipes for the flame to work properly.

 

Propane will generate soot, even though some gas guys say it won't. Sounds like there should be some warranty on that furnace. Did you have a power outage or surge? that won't help electronic controls. Good thing you had a back-up heat source.