Problem with 7500

[RAA]

My 7500 had been working really well in the past couple weeks, my guess it was this years good corn crop.
Anyway, Saturday I went to do my usual check up and noticed the flames were blowing to the left (when looking in the glass), and the pot was filling up. I increased the draft and also noticed smoke coming out of the clean outs below the door.
There was a strong wind from the East and checked the exhaust. The elbow had fallen off so I re installed that. Still no change.
After some more messing around I unhooked the white wire from the temp switch that runs to the room fan. With the room fan off there is no smoke out of the clean outs or intake from draft and the flames are burning straight up.
I took the hot air duct off and covered the opening with a chunk of cardboard and the flame went out and smoke came out everywhere. I was told if you do that and the fire goes out they heat exchangers have a hole in them. Do I have junk heat exchangers? What else can be done or check?

[wes]

The best way I have found to check the exchangers is to build a fire and then smother it out with pellets to get a dense smoke. Then turn the unit off so the exhaust blower stops. Watch the exchangers with a light to see if any smoke comes out of them.
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3500P clinker pot in house. 3500P stirrer pot and baby countryside with cast iron pot in shop.


If we forget that we are one nation under GOD, we will be a nation gone under.-Ronald Reagan

[RAA]

I will try that as see what happens.

Still don't get why the fire would go out if the room air outlet is covered? Isn't that air supposed to be separated from the combustion area? Where could it be leaking?

[tallcorn]

My first impression would be the furnace is plugged up with ash and soot behind the burn chamber, on the right side when facing the furnace. Check through the cleanout openings with the bottom cleanouts open with a stiff wire or throttle cable housing.
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Countryside 3500P (pedestal version) used 8-9 yrs, 24/7 during days requiring heat. All original motors. Burns moldy corn, and pellets equally well. Burn it if you got it.

[RAA]

I have a air nozzle that I stick in from the bottom of the clean outs, from the ash pan drawer and blow compressed air to clean it out. That was done earlier in the day. Nothing felt like it was plugged at the time.

[tallcorn]

Describe your exhaust system; length, elbows, vertical or horizontal, etc.
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Countryside 3500P (pedestal version) used 8-9 yrs, 24/7 during days requiring heat. All original motors. Burns moldy corn, and pellets equally well. Burn it if you got it.

[RAA]

Tee out the back of unit 5 foot vertical run to a 90 deg elbow and a 3' horizontal run to the outside.

[tallcorn]

[RAA]

Have been blowing out the clean outs like that for years, it does work. I do it once or twice a week. Yes the tee does have a clean out and I do remove it for cleaning.
I haven't had time to mess with the furnace, hopefully tonight.

I still want to know why the fire goes out when the room air outlet is blocked off. That air shouldn't have anything to do with the fire.

[tallcorn]

[RAA]

[tallcorn]

I had to think about this for awhile. If the heat exchanger tubes are leaking exhaust then it follows that blocking the room air outlet could blow air back through the burned through holes in the heat exchanger tubes and that would reduce the negative draft through the burn pot and the fire would go out. I don't know if you could feel around the tubes or use a light and a mirror to inspect the tubes.
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Countryside 3500P (pedestal version) used 8-9 yrs, 24/7 during days requiring heat. All original motors. Burns moldy corn, and pellets equally well. Burn it if you got it.

[RAA]

I had time to fire up the furnace last night. Cleaned out the tee and clean outs good. Got a fire going and the same problem, flame was lazy and blowing to the left once the room fan was running.
Took some pellets to smother the fire, while the duct was off the room air outlet. When the room fan was running I couldn't see any smoke coming from the heat exchangers, but it did smell like burnt corn. I unplugged the room fan and still no smoke from exchangers. I then unplugged the power, then there was smoke. Lots of smoke! Ran around the house at 11:00pm pulling batteries from smoke detectors so the kids and wife wouldn't wake up to the sound of fire alarms. Surprised the smell of smoke didn't wake them, guess that's why smoke detectors are so important.
So it looks like the exchangers are shot. Anybody been down that road, is there a fix or is it new furnace time?

[tallcorn]

Where did you buy your furnace? I think the next step is to contact a dealer or the factory.

http://www.americanenergysystems.com/Stock/LibraryFiles/I-00013InfoBTechnicalDepartmentpersonnel-propercontactprocedure3.pdf
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Countryside 3500P (pedestal version) used 8-9 yrs, 24/7 during days requiring heat. All original motors. Burns moldy corn, and pellets equally well. Burn it if you got it.

[RAA]

Dealers...HA! Dealer I got this one from hasn't been much help from the beginning. They are no longer a dealer. Just looked on the website for the phone number of the dealer that was 40 miles from me. I contacted him last year with some concerns and he wouldn't help, told me to contact the dealer where the furnace came from. Funny, I see he's not in business any more. Needless to say not impressed with the dealer support in my area.
Looks like it might be easier just to get a different furnace. This thing is 6 years old, guessing the factory isn't going to be much help.