Thread: Problem with a fireplace insert

A couple of years ago I bought a house that had a fireplace with an insert installed. The insert is a Forester 4100 I think. The design is very close to this: http://rs.woodmanspartsplus.com/company_41/4100.pdf Note part number 3. I suppose this is the damper? It appears to be just a steel plate that slides back and forth via the handle.

The problem is that this insert just flat chews through wood without making much heat - at least not much males it into the living area. It is better than just a fireplace, but nowhere near what I would expect. My only frame of reference though, is a Vermont Castings stove that I had in a house several years back. That thing would easily run you out of the house. Back to the insert... Not only does it not produce sufficient heat, a load of wood in the firebox generally yields a pile of warmish coals when banked for the night.

Is the lack of the damper causing this? I have been looking at wood stoves, but if I can get this insert to run better, I would rather keep it and avoid the hassle and expense of swapping out. A small amount of googling has yielded no sources for this damper. Anybody got a source? Reckon this is anything more complicated than a piece of plate steel? Thanks in advance.

i think you need to take it out and clean it very well. make sure you clean off the top and sides of the top plate inside the fire box. move it all rounds to loosen all the fone ash. just clean everything very well. mine was working like crap after a few years. after i cleaned it all out it made a big difference. that fine ash gets into everything and eventually clogs up the stove. mike

yeah I'm no expert, but I have the same set up, or similar, and I think what you need to do is add a damper to your stovepipe if you use it like I do with my insert... If you're insert is indeed in a fireplace, it will be much harder for you to control the damper.

What I'm saying is that part you are pointing out isn't designed to close more than about 1/4-1/2" on the backside... it isn't designed to close for fine burn control... probably built that way for safety or something.

I'm going to add a damper to my stovepipe that will give me very fine burn control this winter.

You could also modify that damper that you have... you'd have to weld on some more metal or attach metal to the damper so that it can close completely or very close to all the way for finer burn control. I'm just going to add a $6 damper to my stovepipe and be done with it.

Thanks guys. Coupla things. First, regarding the damper, I did not explicitly state this ini the first post, but it ain't got one. #3 is missing. And it's a brick fireplace and chimney, so no damper there either. What I have is a hole in the top of the insert which goes straight to the top of the chimney.

Husky, I am considering trying to clean it out as you said. The issues I have with that is I think it may be all welded, inside and out. Plus, that sucker weighs a few hundred pounds and it doesn't slide too good on the brick. If I manage to get the thing out, I'm liable to just replace it.

Hi Wing Nut. I work for a manufacturer so if you dont mind I can give you a few pointers:

1) It looks like an older unit. If you can get that part #3 damper it should help somewhat. However, keep in mind this is not a high efficiency unit and most of the heat will still likely go up the chimney.

2) if you look at a new insert, all of them are now High Efficiency EPA unit. Which means you should see efficiencies in the range of 75% to 85%. They burn extremely clean since they also have a secondary combustion to burn the smoke. It also means at least 1/3 less cordwood per year.

3) If you go a a newer one, put the biggest you can find in the opening. Give us your fireplace dimensions and we'll help you with it.

4) With a new one you will need to drop in a 6" liner down the chimney to make it draft properly.

On Northern Tools you can buy a high efficiency insert for about $800. Prices go up from there. A liner is about $400

Fyrebug - Yeah that is an older unit. I have been contemplating a free standing wood stove to replace the insert. This, primarily because I heated a house with one at one time. It was great! This insert doesn't hold a candle to that stove. One issue I had with spending money on another insert is that is seems to me that an insert is going to heat the brick hearth. While I understand the concept of a heat sink, I seems like an insert would be less efficient than a free standing stove. Is that correct? Can a modern insert get close to the performance of a stove?

People around here talk about "Buck Stoves" that run them out of the room. Wish I could make that happen with this one.

I am playing with the idea of getting a wood stove that will sit on the hearth and run the the "chimney" out the back of the stove and up the brick chimney. I've been unable to obtain a good answer as to whether or not that is viable from a safety and performance standpoint.

Just got a new Northern Tools catalog and have been eyeballing their offerings.

[Can't tell how deep the fireplace is. That insert is gonna be a booger to pull out.]

Originally Posted by Wing Nut

Fyrebug - Yeah that is an older unit. I have been contemplating a free standing wood stove to replace the insert. This, primarily because I heated a house with one at one time. It was great! This insert doesn't hold a candle to that stove. One issue I had with spending money on another insert is that is seems to me that an insert is going to heat the brick hearth. While I understand the concept of a heat sink, I seems like an insert would be less efficient than a free standing stove. Is that correct? Can a modern insert get close to the performance of a stove?

People around here talk about "Buck Stoves" that run them out of the room. Wish I could make that happen with this one.

I am playing with the idea of getting a wood stove that will sit on the hearth and run the the "chimney" out the back of the stove and up the brick chimney. I've been unable to obtain a good answer as to whether or not that is viable from a safety and performance standpoint.

Just got a new Northern Tools catalog and have been eyeballing their offerings.

[Can't tell how deep the fireplace is. That insert is gonna be a booger to pull out.]

You are right, typically a stove will radiate more heat from all around. However and insert has a blower that captures and pushes hot air around the unit back into your room. As far as the masonry wall becoming a heat sink, that's easy to fix. Insulate around the insert with Rockwool. Make sure to also buy or make your own block off plate where the damper plate used to be. You can use sheet metal of cement board. This is to avoid cold air and crud to fall on top of your insert.

I've installed my own and done all the above and it works great.

Originally Posted by Wing Nut

Thanks guys. Coupla things. First, regarding the damper, I did not explicitly state this ini the first post, but it ain't got one. #3 is missing. And it's a brick fireplace and chimney, so no damper there either. What I have is a hole in the top of the insert which goes straight to the top of the chimney.

Husky, I am considering trying to clean it out as you said. The issues I have with that is I think it may be all welded, inside and out. Plus, that sucker weighs a few hundred pounds and it doesn't slide too good on the brick. If I manage to get the thing out, I'm liable to just replace it.

that's the whole problem, no damper. You get that part replaced and you will get a lot more useable heat out of your insert.

We had the exact same insert in our cabin in NW WI. It was installed in a brick fireplace & performed poorly at best. If the power went out you would freeze to death in there. We found most of the heat was trapped in the wall behind the surround. We tore the unti out & trashed it after struggeling with it for 8-9 years. This is the worst perfoming insert Iv'e ever used. A old fisher fireplace insert would run circles around this at temps to -30