CB1200-I leaking smoke at startup

[eandbnorton]

I am a newbie and my newly installed CB-1200 insert is leaking ALOT of smoke ... at start up. The smoke smell permeates the whole house. All 2500 ft sq. One morning after the stove had cycled on and off a few time throughout the night, the whole downstairs was filled with smoke (oddly not enough to set off the smoke detectors). Its not coming from out the venting (just had the installer replace the whole venting and re-seal it). Tonight I saw smoke seeping from the exhaust blower... but not sure if its really coming from there or just looks that way with a flashlight. This smoke leakage only happens when the stove is cold and only at startup and for about 5 minutes after that. Any ideas on how to fix this problem...is there really nothing wrong and its just something we have to live with? Other than that, stove works great and we love it!

Please help!

 

[cncpro]

It's not OK and you shouldn't have to live with it.

I can barely notice the faintest odor of smoke on rare occasions from my CB1200 but 99% of the time there is no smell at all.

Earlier this year I realized that my smoke problems were being caused by the door seal. I had the latch side adjusted to pull in tight but the hinge side was too loose. A 5 minute adjustment made all the difference for me.

I think you just need to re-examine the whole unit and eventually you'll figure it out.

Just because you had an installer re-seal it unfortunately doesn't prove anything. Good service can be hard to find. Keep double-checking everything suspicious and you'll figure it out eventually.

The top few things I'd be looking for would be :

1. Door Seal
2. Re-check venting and put a glob of silicone anyplace doubtful
3. Look for missing or damaged gaskets around exhaust blower, etc...

You should expect to have a burning paint smell with a new stove until it gets really hot for a long time then eventually the odor stops. It doesn't sound like this is your issue but since you're a noob I figure it couldn't hurt to mention.

 

[Marbleguy]

Something is not right. I have never had the smell of smoke in the house at all. I do get smoke in the chamber at start up but it is all exausted just as soon as the pellets ignite. I do notice that I have quite a bit more smoke in the chamber when I start the stove on the high setting. With the weather we are having now, I keep the setting on medium as the stove is cycling on and off quite a bit.

 

[eandbnorton]

I only bought the stove back in June (2009) and have only been running it since October. Wondering if I should just get a whole new unit since its still under warranty. Maybe I got a lemon? cncpro, I have done #'s 1 and 2, and last night I thought #3 might be the problem. We'll check that next. Any other suggestions are more than welcome. Thanks

 

[slls]

The stove operates in a vacuum, the leak has to be at the vent.

 

[gbreda]

Had the exact same thing after install. Taped all seams and then taped manufacture seams on 90 deg elbow. Problem solved.

 

[cncpro]

The stove operates in a vacuum, the leak has to be at the vent.

In theory your statement is correct but I was getting startup smoke through my door gasket so for some reason it doesn't always work out that way.

 

[eandbnorton]

Well, the exhaust blower sucks out the air from the stove and blows it up the vent...right? (At least that's what it says in the manual). Could the leak also possibly come from the exhaust blower? I'm going to check the vent again. That's probably where the leak is coming from though.

 

[gbreda]

When diagnosing my issue, it was suggested to use a drop light with the room darkened to find the leak at startup. This did help me see where it was leaking. Put the light behind the piping during startup and try if you can actually see the smoke coming out. I would think that this would help with a stove issue as well.

 

[eandbnorton]

The stove operates in a vacuum, the leak has to be at the vent.

In theory your statement is correct but I was getting startup smoke through my door gasket so for some reason it doesn't always work out that way.

How did you fix this? Was it a leak from the door? Or from the actual blower? Here's what mine looks like.

 

[imacman]

I've never had or worked on an insert, so i don't know how things are laid out, but since you saw smoke near the combustion blower, and feel that the vent system is well sealed, my next thing to do would be to make sure that all the bolts/nuts that hold the blower in place are tight.

I tend to agree with Sils above...these stoves work on negative pressure in the firebox, so if the door gasket was leaking at startup, the worst that should happen is that extra air from the room will be sucked IN. However, the combustion blower has both negative AND pos. pressure.

Also, can you visually see that there is a gasket behind the comb. blower? Not out of the realm of possibility that the blower got installed w/o a gasket.

 

[cncpro]

The stove operates in a vacuum, the leak has to be at the vent.

In theory your statement is correct but I was getting startup smoke through my door gasket so for some reason it doesn't always work out that way.

How did you fix this? Was it a leak from the door? Or from the actual blower? Here's what mine looks like.

Mine was from the main door seal. The 2 hinges seen in your picture (attached to the big door with glass windows) should have some adjustment slots. Loosen them up one at a time and tweak them just a little. Of course you'll have to be careful not to make it so tight that the door flexes and breaks your glass...

 

[begreen]

Our 1200i door needed adjustment as well. If too many pellets dropped in the pot for a cold start, there would be a lot of smoke generated until the pellets ignited. This could result in a mini explosion (just a big poof) that could blow some smoke out of the door gasket. I could also hear a faint whistle when the stove was running. Both were due to the door needing to be tightened a little. The other fix was to reduce the pellet feed so that just enough pellets dropped into the pot. After that, no smoke smell.

I am curious about the flue on the OP's insert. Can you describe it?

 

[slls]

My door has a gap all across the top, it's called air wash. Nothing has ever come out , just in. When I put my fingers near the top of the glass when running, I can feel the cool draft being sucked in.

 

[eandbnorton]

Wahoo. No more smoke. Turns out the chimney wasn't sealed enough. Sealed the top and bottom gaps and we are sitting smoke free.