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[halfpress]

Everyone says there should be nothing more than a wisp of smoke - if that - coming out of an idling Heatmor 200 CSS. We're in our second season and our furnace has always had vastly more than a wisp from the day it was installed. It's not a thick column - more like a Halloween-esque witch's cauldron spilling from the chimney whenever it's idle.

I can't seem to find the source if this is, in fact, a problem. The blower seems fine and the flap on it appears to close properly when I test it. The door seal seems undamaged, but I'm not sure how to test it further. The spring-loaded panel that covers the ARD tube seems fine. My dealer told me to put a wad of steel wool in the ARD tube, but the first time I did that I just about got set on fire by the flames that rolled out the door. The steel wool came out pretty fast after that.

The furnace sits on a concrete pad, has all the sand in it that was required and is even silicone caulked all around its base.

I've wondered if adding four feet of proper twist-lock chimney and a spark arrestor on top would help matters... but I've just finished reading a thread where several people who added chimney actually saw increased draw that worsened the problem.

Any thoughts?

 - Aaron

NOTE: Let me add that, when idle and smoking, I never open the door to a low burning fire. In fact, it often takes a moment to see any coals start to glow due to the air from the open door.

[MattyNH]

Is your water temp higher than normal? That would be a good indicator of a air leak..Different type of wood burning? Is it wet or green?... Everyone has theories of what a wisp of smoke is..If is running fine I wouldn't worry about it..

[rhugg]

You are probably worrying a little much.  Mine hardly smokes at all when off IF I have clean dry wood ... especially if it is all charred.  If however, I throw paper in when the blower is off I get a good bit of smoke.  So those are the two extremes.  Everyone worris about the flapper and door seal but nothing closes the exhaust.  Some air can come down the chimney, while there is no draft there is some O2 in the burn chamber.

[halfpress]

 The smoke I get seems to not vary much by wood type. Obviously, it puts out a lot of smoke when it first fires up from idle and when it goes back to idle. When going full bore, I see nothing but rippling heat waves and virtually no smoke.

  I may take a shot of it doing its average idle smoke and post it soon for reference.

  One thing I've wondered is whether the roofline of the shed that extends partly over the front of the furnace is angled such that it's whipping wind either right across or down into the chimney. This is one reason I thought about extending the chimney. The desire for a spark arrestor is because I've seen enough roman candle-like behavior sometimes that I worry about setting the neighborhood on fire on a dry, windy night.

  Granted, it seems to smoke whether it's windy or not.

  Lastly, I do get a lot of black gunky/crusty stuff on the door and on the walls of the firebox, but I seldom see any watery black liquid running down any of the surfaces. I didn't open our flue to clean it until the start of this second season and I expected it to be full of stuff - name creosote. It was virtually empty except for some light ash which was easily pushed back down into the firebox.

  So, yeah... maybe I'm fine.

Thanks for the input!
  - Aaron

[tbone]

I've always had a stack on my heatmor...I'm sure I would have caught something on fire by now without it.  Its a 20 footer and I still get some sparks coming out on occasion...when I have a really roaring fire.  If I'm burning seasoned wood during my burn cycle I have just clear waves coming out of my stack; but once the cycle ends I do have smoke...not a lot though.  My guess is if you don't have fire or strong glowing coals between burn cycles, you don't have a leak.

[mikenc]

If you add more flue it will increase stack draw. If you are not over heating when fan shuts down you are probably ok. You can check for leaks by closing off chimney flue with something while fan is running. Any leak should show by smoke comeing out around door, damper where ever. I have checked mine this way and found door seal leaking.