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Gas furnace ?? [message #190794] Mon, 19 November 2012 21:37 Go to previous message
C Boyd is currently offline  C Boyd   United States
Messages: 2629
Registered: April 2006
Karma:
Senior Member
About 2 years ago Gene barrow & I adjusted my Solair mixture for a howling issue. Seemed to repair the noise. Last year at ES in Milan, Mi it started howling again while we were having a business meeting. Was loud enough to hear in the building. Switched to elec heater and adjusted it again when I got home, no howling. Since then Cat got us a Carbon Monoxide detector. Last weekend in N.C. I fired it up (first time with the detector) and after about 3 cycles the detector started barking. I also noted that after a few minutes of running the furnace burner sound would randomly change slightly. So I`m thinkin maybe the heat exchancer has a break in it allowing the mixture to change and allowing burnt gas into the coach air flow???
I go to the Avion with the same furnace and remove it first to kinda see what I`m gettin in to. I found the exhaust vent to the outside was rusted to the flange solid. I had to break the weld on the plate to get the furnace to slide out. I then cut a groove in the remaining coller on the bench with a dremmel and took it off. The coller covered the slot vents in the exhaust pipe cover. It was slid on at least 1 1/2 "
When I went to take the furnace out of the Crestmont I took the outside vents off to see how bad they were and found the flanges were not even touching the furnace, no way they would slide on the intake and exhaust pipes. They was 1/2" between the pipe end and the outside flange. The outside flanges were pristine. Looking inside the Crestmont the furnace is under the rear dinette seat and is pushed as far outboard as the interior wall will allow. I can look behind the furnace and see the slots in the exhaust pipe cover inside the coach. They were stuck in the holes in the wall but not deep enough to catch the outside vent flanges. I did put the furnace out of the Avion in but it would not fire. Maybe I didn`t hold the reset button long enough but I did start smelling Propane so I`m thinkin Ignitor maybe. I`ll start with that tomorrow..
I do not know how long this carbon monoxide condition has existed, since new, or 2 years ago with the first howl, or just this trip.
My alternatives to fitment are to cut the bottom of the curved wall board inside the dinette seat and extend the gas inlet to get the furnace 2" closer to the outside wall or take the furnace to the muffler shop and get 2" extensions made. I`m thinkin muffler shop.

Now the QUESTIONS.
Could the misalignment of the exhaust and intake pipes cause the carbon monoxide detector to bark?

Can I put small air pressure maybe 15 lb on the exhaust outlet and soap the out side of the heat exchanger for bubbles on the bench?

I`m thinkin I got 2 problems.

C. Boyd
76 Crestmont
East Tennessee

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