smokeback after shutdown....

Where does the smoke comes out?
Check gaskets and seals, maybe leaf blower damaged something.

Please describe your venting. I'm assuming that during start up your combustion blower is working and that when the smoke back occurs it is off.

mscj said:

Venting is horizontal 18" out the wall to the T, 6 foot vertical to the cap--all 3". I think with the 90's in the vent I'm right on the borderline of requiring 4", but wasn't a problem last year. Combustion blower working per design, goes to high when the off button is pressed and stays there until the temp gets low enough to shut down the stove. Only thing that has changed since last year is the pellet brand.....could the hardwood pellets be smoldering a bit longer than the softwood pellets did?

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The pellets that you ejected into the ash pan are likely still smoldering.

What I don't understand is why you open the damper, you shouldn't need to.

You only have one 90 in the vent setup as described provided it has a vertical vent termination cap, the EVL is 9.5 well within bounds, now I'd check the termination cap and see if it is partially plugged.

Can you post a picture of the venting on the outside?

Here is a Possibility, and I have had it happen on the Quads.

After a shutdown and during the cool off period, the firepot should burn out completely.

At this point there should not be any materials in the POT to smoke.

Likley what is happening is that a pellet or two are falling into the still warm pot and smoldering.

With the blowers off the smoke has to go somehwere, so it vents back through the air inlet to the pot and into the room.


Our Quads will do this with some pellets.

Do a test and when you smell the smoke, go open the door and see if there are a few smoldering pellets in the POT.

I have my stove all direct vented and this is not an issue generally.

With a tall stack, as the fire dies out the cold air in the upper reaches of the pipe tends to fall back and will tend to cause a reverse flow.

If you can nail it down to the errant pellets falling into the pot, then you may want to change brands or add a stack cap that will use exisiting breezes to extract air from the vent.

A "weathervane" type hood that causes a slight suction on the stack may be all thats needed.



Keep us posted

Snowy

Yes you are over 15 EVL with that 3" venting.

I'm more inclined to think that the smoke is exiting via the air wash, but if the door gasket is bad it can also get out there. H*ll it can even come out of the hooper or the air intake.

You also need to correct your venting.

Does your stove have an OAK (outside air kit) or did I miss this in your description.

SmokeyTheBear said:

Yes you are over 15 EVL with that 3" venting.

I'm more inclined to think that the smoke is exiting via the air wash, but if the door gasket is bad it can also get out there. H*ll it can even come out of the hooper or the air intake.

You also need to correct your venting.

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Is there some generic table you are using to figure this out? The manual for his stove is very vague, it basically says 3" venting is usually OK, but you might need 4" if it doesn't work right (which is very helpful after you already purchased and installed 3" vent). All the Quadrafire manuals I work with have their own EVL tables and charts. According the one of the Quad manuals he could go up to about 18' EVL at his elevation of 3,366, and I am calculating at least a 21' EVL for his vent (based off the Quad chart). So according to that chart, yes 4" would be needed.

jtp10181 said:

SmokeyTheBear said:

Yes you are over 15 EVL with that 3" venting.

I'm more inclined to think that the smoke is exiting via the air wash, but if the door gasket is bad it can also get out there. H*ll it can even come out of the hooper or the air intake.

You also need to correct your venting.

Click to expand...

Is there some generic table you are using to figure this out? The manual for his stove is very vague, it basically says 3" venting is usually OK, but you might need 4" if it doesn't work right (which is very helpful after you already purchased and installed 3" vent). All the Quadrafire manuals I work with have their own EVL tables and charts. According the one of the Quad manuals he could go up to about 18' EVL at his elevation of 3,366, and I am calculating at least a 21' EVL for his vent (based off the Quad chart). So according to that chart, yes 4" would be needed.

Click to expand...

Yes.

There are several in fact, that say unless the manufacturer indicates otherwise EVL's above 15' require 4" or larger. In fact there is at least one manufacturer that says above a certain altitude and EVL of more than 6 requires 4".

I've also seen 45 degree bends being called as being an EVL of 2.5' however since a 45 degree bend is not exactly half a 90 in terms of length in at least one of the directions (horizontal) the value the general tables quote is an EVL of 3'.

I certainly can understand the frustration this causes, however the very first instruction in the install manuals tells you to read the entire manual before installing or operating the appliance. Given that one should have no trouble returning the unused pipe and getting the correct stuff.

I'm a rather odd critter I tend to read the manual first. Funny I know, been doing it that way for at least the last five decades, saves all kinds of grief.

I didn't do a complete EVL calculation for the OP only a quick back of the eyelids one. Once it crossed 15 the red flag went up.