Can't close the damper without smoke backing into the house

[Cleartron]

Hi All,

I have an old Efel Kamina that's been working in this house for over 50 years. My wife and i have been using it for 2 of those. The stove has done a great job at heating our main level, but I feel like I'm wasting a lot of heat trying to manage the flue damper. I can only close it when there are only charcoal left.

Maybe it's my inexperience with older stoves. I was thinking about replacing it with a Jot F3 CB i saw on facebook due to the lack of space where this one is.

Am I just managing the damper incorrectly, or could there be a seal issue between the stove and the connecting 8" pipe?

Finally, would an update to a Jot F3CB be an improvement due to the secondary burn?

Any help or advice would be appreciated.

Thanks

LM

 

[begreen]

The Jotul F3CB is a smaller heater. It has a burn time of only 4-6 hrs. How large is the area that the Kamina is heating?

So that we understand the setup better, can you describe the entire flue system from stove to chimney top in detail? When was it cleaned last?

 

[Cleartron]

The Jotul F3CB is a smaller heater. It has a burn time of only 4-6 hrs. How large is the area that the Kamina is heating?

So that we understand the setup better, can you describe the entire flue system from stove to chimney top in detail? When was it cleaned last?

The house is a raised ranch, ~2700 sq ft. There is more space in the main living area (top floor) since the master bedroom sits over the garage. The kamina is heating the top floor, and on the lower level, I have an Olympic insert that heats that area. The heat also makes its way up the stairwell by the use of some low-flow floor fans to move air toward the stove.

Overall, we have only used wood to heat the home and can get the bedrooms, which are on the exterior walls with the stove in the center of the house, around 70-73 degrees before heading to bed. The Kamina burn is really only a few hours since I can't close the damper all the way.

We cleaned the chimney in October of last year, and there were no issues during that. They did "remove" or unscrewed the Kamina from the flue to see how if they could clean it from the inside or whether it all had to be done from the room. My concern is that the process of disconnecting it caused a seal issue.

The flue for the Kamina is 8", and goes back about 1-1.5 feet then a straight shot about 20-25 ft out of the chimney. The surrounding walls were built as a radiant wall, which warms up after the stove has been on. There are no beams or sheetrock, just stone and masonry work. The Olympic has a SS lined 6" flue that was added as part of that installation in the early 2000's, where it went into an original fireplace.

 

[begreen]

Does the Kamina have a stainless 8" liner or is it using the chimney flue? If chimney tiles, what is there ID?

 

[yooperdave]

Have your outside temps been warmer when this happens? The warmer temps affect draft. Don't try to damper down as much?

Check your flue just for giggles.

 

[Cleartron]

Does the Kamina have a stainless 8" liner or is it using the chimney flue? If chimney tiles, what is there ID?

it has an 8" liner

 

[Cleartron]

Have your outside temps been warmer when this happens? The warmer temps affect draft. Don't try to damper down as much?

Check your flue just for giggles.

happens no matter the temp. If the logs are burning, (within 30 minutes of it lighting, i cant close it down otherwise smoke smell comes through

 

[Cleartron]

There is also a door, about 12" or so below the flue going into the wall. not sure if I should open this. Here are some pics and how the manual shows it

 

[bholler]

There is also a door, about 12" or so below the flue going into the wall. not sure if I should open this. Here are some pics and how the manual shows it

View attachment 310729 View attachment 310730 View attachment 310731 View attachment 310732 View attachment 310733

Close and seal the cleanout door

 

[Cleartron]

Close and seal the cleanout door

Thanks for the reply. It’s always closed. I only opened it for the picture.

The guy who cleaned our chimney thought it might be a clean out door, but it’s just a cavity that was probably going to be used for that purpose but never implemented.

 

[gzecc]

How long has your wood been split and stacked off the ground?

 

[Cleartron]

How long has your wood been split and stacked off the ground

It's a mix. I have stuff from the previous winter (2022) that I never burned (about 1 cord) that's completely dry(10-12%). I have burned about 1-1.5 cords of Ash that I split and stacked in April/May (around 12%) and I have a Cherry Tree that we brought down around the same time that I split and have confirmed it's between 13-16% moisture.

The same wood burns fine in the Olympic stove. It's only when I close the damper all the way that I smell smoke "leaking through" the back of the stove.

I have a donor stove I took apart that I got for free on Facebook. I'm wondering if the collar seal needs to be replaced. You can see remnants of one on the donor parts (attached). Not even sure where I would get such a part.

 

[gzecc]

It's a mix. I have stuff from the previous winter (2022) that I never burned (about 1 cord) that's completely dry(10-12%). I have burned about 1-1.5 cords of Ash that I split and stacked in April/May (around 12%) and I have a Cherry Tree that we brought down around the same time that I split and have confirmed it's between 13-16% moisture.

The same wood burns fine in the Olympic stove. It's only when I close the damper all the way that I smell smoke "leaking through" the back of the stove.

I have a donor stove I took apart that I got for free on Facebook. I'm wondering if the collar seal needs to be replaced. You can see remnants of one on the donor parts (attached). Not even sure where I would get such a part.

View attachment 310746

In my experience your moisture numbers are too low for conventional firewood.
Are these fresh splits you're measuring?
Press your meter onto your palm (don't draw blood). you should get around ~33% .
Then test piece of trim molding (unpainted) thats been in your house for years. Should be single digits.
I suspect your wood is sub optimal. In some situations the wood needs to be exceptionally dry. In other stoves not so much.

 

[Defiant 3]

Might be overthinking just a trifle here. That is a full on flue damper, which when fully closed odstructs the flue like 90% or more. It may be that you simply can't obstruct the flue that completely, indeed it's not necessarily intended for that under normal operation. Use it

 

[Defiant 3]

Use it to slow the burn rate by partially closing to an appropriate point.

 

[stoveliker]

I agree; take a piece of wood inside, let it sit for 24 hrs to get up to room temperature. Then split it in half and measure on the freshly exposed surface.

And yes, dampers are not meant as primary regulation of the fire. That role is for the air intake (often mis-named as damper). Flue dampers are to get the draft of the flue in check if it is too large. That.may not be needed here (as suggested by the smells coming out when the damper is closed, rather than being sucked up the flue).

You may simply not be able to get longer burns with a stove this old.

I would suggest a modern stove, appropriately sized.

 

[begreen]

Might be overthinking just a trifle here. That is a full on flue damper, which when fully closed odstructs the flue like 90% or more. It may be that you simply can't obstruct the flue that completely, indeed it's not necessarily intended for that under normal operation. Use it

I'd be tempted to trim the damper a bit more so that it admitted say 25% of the flue gases when closed. This could be done by cutting it or drilling some holes to equal that amount.
If replacing the Kamina, consider a larger Jotul like the F45 or even the F55.