Hot Wall Concerns

[bikepo]

Hello and thanks in advance for reading. I have an 8-10 year old Morso 2110. It is installed in a 10'x13' room in a 100-year old home in Maryland. All clearances to walls and floor are within spec. Notably, the distance from the rear of the stove to the wall is only 16", but the wall is non-combustable concrete board, so I believe this is ok. It has rear and bottom heat shields installed. The stove vents directly horizontal to the wall through a 16" semi-bent, semi-rising (basically two 45 degree joints that were used to allow the stove to be placed at appropriate distances to the walls) run of double wall pipe. This double wall connects to either single or double wall liner that is installed within a brick chimney (maybe 18" by 18"). The large chimney that you see in the picture is false, it's just a small chimney with the wall built out to make it look like a traditional fireplace. This liner is surrounded by an unknown quantity of kitty-litter style insulation. The liner goes to the top of the masonry chimney. A chimney sweep inspected and cleaned the liner about three years ago and did not note any problems with it. However, he also failed to note the improper clearances around the stove, and focused most of his effort on trying to sell me a new stove to replace my "old" one. So, I don't trust that he was competent or really paying attention.

The stove was installed prior to my buying the house, so I don't really know who did it. Rumor has it that it was installed professionally. However, the original single-wall pipe had charred the drywall that it passed through and the clearances to the rear and side walls as well as the tile pad it sits on were all non-compliant with the distances noted on the stove's safety info plate. So, I replaced the drywall with concrete board, moved the stove to be within specs, extended the tile pad outward to meet the spec, and replaced the single-wall with double wall.

This was all great and I felt pretty pleased with myself. However, problems remain that feel significant to me. Specifically, there is a tremendous heat on the wall behind the stove and up into the upstairs bedroom that the chimney proceeds through. The mantle you see above the stove gets hot enough that the paint blisters. The wall above that mantle gets very, very hot. Sorry, I haven't been able to measure the temperature, but it's too hot to hold your hand on and the paint has a vaguely baked look to it. About 12-16 feet up the vertical run, the chimney still feels very hot. It is possible to hold your hand on it, but it's not comfortable. This heat is theoretically coming through the liner, the insulation, the masonry chimney, and the slat and lath plaster. So while it does heat the bedroom nicely, it is a worrying amount of heat.

We have always burned seasoned wood and nothing more. Ok, sometimes after a few drinks I'll burn the mail for fun, but that's not the issue here.

So, this is the issue. I'm most concerned about safety of course. I just don't know what's going on and to have that much heat in/on/out of the wall does not feel right. The secondary concerns is aesthetics. The paint blistering off the mantle isn't very nice looking. In terms of moving forward, and solution must include a working, safe, wood burning stove. We love to use it and we have access to lots of wood. The heating performance of the stove it mediocre in my opinion. Perhaps because the house is old-school non-open floorplan, the stove really only heats the room it is in and the bedroom above. However, it is very pretty when in use and it's in great condition.

Anyways, any advice or thoughts are very welcome. All options are on the table. We can replace with a smaller stove, have the chimney re-lined, move the stove to a different room, replace the horizontal pipe with a vertical one, etc. We just need to get this working and safe.

Thanks!

 

[begreen]

It sounds like there are two issues here, high temps on the wall and moving the heat out of the room.

Horizontal runs of pipe get hot. The 2110 is a good small heater and as you note it can get hot. How hot is important. It might help to buy or borrow an infrared temp gun to measure how hot the stove top is and how hot the pipe, mantel and wall are getting. It sounds like there is a chimney liner installed with vermiculite insulation surrounding it. Is the "kitty litter" material greyish-brown? It's possible that when they poured the insulation that the liner was not centered in the chimney and in some areas is actually touching the chimney brick. if so the heat from the liner will be transmitted so that the brick feels hot to the touch. An IR thermometer will help determine how hot. If it is over 170F then it could be advisable to pull the liner, remove the insulating flakes and insulate the liner with a ceramic wool blanket that will insure that a safer level of less heat is transmitted to the chimney brick. It will still get warm, but not as warm as to be a safety issue. The best one that can determine this is a certified sweep. You can look up the nearest qualified sweeps by going to www.csia.org and typing in your zip code. The mantel protection may end up needing a heat shield on the pipe.

As for moving the heat, can you make a quick sketch of the first floor plan and post a picture of it here? It could be that a simple table fan can dramatically improve heat distribution by blowing cooler air from another part of the house into the room.

 

[Grisu]

Another potential safety issue: Does the hearth still have a depth of 16" measured from the door? Looking at your sideways pic it may fall a bit short.

How do you operate the air control? After the fire is established are you reducing the primary air? What is your final setting? Maybe your problem is that you send too much heat up the flue.

 

[bikepo]

Thank you both. Here are some responses:

Regarding the heat of the horizontal run, would we be better off to have a vertical run first, before we do horizontal into the wall? It seems this would bleed off some heat, but I'm not sure if that's actually true.

Regarding the IR thermometer. I do have one. I could burn the stove here tomorrow, but it is quite hot out. Are there particular temperatures that are unacceptable? I'll update this thread once I've burned it tomorrow afternoon.

Yes, the kitty litter is greyish brown.

I think I will give a chance to another chimney sweep. The first guy that I ultimately didn't trust was a certified sweep, but also a goon. I probably shouldn't judge everyone by him.

Attached is a semi-accurate floor plan. The dimensions are not correct, but the general shape and location of doors is. How about a vent just behind the stove on the wall that blows toward the stove and draws its air from across the bottom floor? There are other ideas I've seen online, like radiators and the such. I'm willing to try anything, but I'd favor proven solutions.

Hearth depth from door is ok. That 1/2 size row of tile was added to make sure the front clearance was per spec.

In terms of burning settings, we start the stove on wide open and eventually damp it down fully. Even fully dampened at the inlet control for hours, the wall behind the stove is blistering.

Thanks,
Mark

 

[jatoxico]

Did the chimney ever serve for additional fireplaces like in the bedroom? Wondering if an old thimble was not properly sealed. Considering the age of the house I'd be concerned too that the liner is in direct contact framing or lathe. Inspection is definitely required. If there is an undiagnosed issue each time you burn the possibility of a problem increases. Replacement with a fully insulated liner would give a lot of peace of mind.

 

[bholler]

Replacement with a fully insulated liner would give a lot of peace of mind.

It is insulated i would be much more concerned with the wall pass thru than the liner in this case.

Has anyone ever investigated the thimble for proper clearance?

 

[begreen]

Had the same concern about the thimble. Mark, do you remember what surrounded the thimble and for how far when you removed the sheetrock and put up the cement board? Did you by any chance take a picture at that time?

 

[begreen]

Attached is a semi-accurate floor plan. The dimensions are not correct, but the general shape and location of doors is. How about a vent just behind the stove on the wall that blows toward the stove and draws its air from across the bottom floor? There are other ideas I've seen online, like radiators and the such. I'm willing to try anything, but I'd favor proven solutions.

Thanks for posting the floor plan. It looks like you could set up a nice circular air flow that would reduce the heat in the den while distributing the heat to the other rooms. Try doing this simple test first when the weather gets cold. It's cheap and will help you settle on what works best. Take a regular table or box fan and set it on the floor, in either the living room or the kitchen door opening into the stove room. Point it so that it is blowing into the den. Turn it on low speed. After about 15-30 minutes you should note a 5-10 degree drop in the stove room temp and the adjacent room temp should go up correspondingly. You'll have to decide which room after the den you want to heat up next. If it is the kitchen then put the fan in the living room doorway. If it is the living room, then put the fan in the kitchen doorway blowing air into the den. That will create a low pressure zone behind the fan which will pull the heat through the other rooms.

 

[jatoxico]

It is insulated

I understood it was insulated with loose pour in type insulation. In that case what guarantees equal distribution and no hot spots? If I'm mistaken I stand corrected. That the wall 12' up is almost too hot to touch would concern me. According to the OP the original installer did not honor the proper clearances so what else wasn't done right?

 

[begreen]

That's the way I understood it too. It illustrates one of the risks of poured in insulation unless spacers are put on the liner first.

 

[bholler]

I understood it was insulated with loose pour in type insulation. In that case what guarantees equal distribution and no hot spots? If I'm mistaken I stand corrected. That the wall 12' up is almost too hot to touch would concern me. According to the OP the original installer did not honor the proper clearances so what else wasn't done right?

fair enough no way to know if it was done correctly

 

[bikepo]

fair enough no way to know if it was done correctly

Hello Again. Yes, basically the more I hear from you all and think about the sketchy clearances, the more I think the liner was probably installed poorly and maybe isn't centered or has other problems. I'm just going to go ahead with the ceramic-wool insulated liner.

For other openings, yes the woman I bought the house from said that there was at least one "hole" in the chimney being covered by a paper plate. I suspect that this was an inlet for another stove and that she had it plastered over.

When I get the better liner installed, is it advisable to have a vertical run before going horizontal into the wall?

 

[Grisu]

When I get the better liner installed, is it advisable to have a vertical run before going horizontal into the wall?

Depends on the stove you want to install. A rear-vented one on a long enough insulated liner should draft well enough to not be a problem.

For other openings, yes the woman I bought the house from said that there was at least one "hole" in the chimney being covered by a paper plate.

Paper plate? That sounds sketchy. After pulling the liner and removing the vermiculite I suggest a level 2 inspection by a sweep (lowering down a camera) to locate that hole and close it up properly if needed. The inspection should also reveal whether there are other problems. BeGreen reported of a case where the chimney was just the clay liner on the house side while the brick was only on the 3 exterior sides. Fortunately, they could put out the fire before the house was lost and no one got injured.

 

[begreen]

Regrettably in that case a level 2 inspection would probably not have found what the contractors had buried behind sheetrock decades earlier. From the inside of the chimney this was not apparent. They now have a full insulated liner in the chimney.

In our house, when I removed the entire fireplace, I found two takeoffs on the unlined chimney. One actually had wood covering it, the other had a plaster plug.

 

[Grisu]

That's true. At least the inspection would locate the other hole and reveal any other interior problems. Based on the description of the OP I am wondering whether there is really a masonry chimney behind the lath and plaster. Potentially they need to make a hole (or use the old one) to get an idea what is in the space between wall and liner. Maybe that was never built as a chimney but rather a chase but then they put just a liner down there and not class A? That "fake" fireplace would support such a possibility.

 

[begreen]

This double wall connects to either single or double wall liner that is installed within a brick chimney (maybe 18" by 18").

 

[Grisu]

That's what you see downstairs and maybe on the roof. I was talking about the upstairs bedroom wall. Even with the liner touching the masonry chimney in places I have a hard time imagining that the wall would be hot to the touch through masonry, lath and plaster.

 

[begreen]

We had a stainless liner, no insulation, in the old fireplace chimney. On the stairway side the chimney brick was just plastered over. After a 24 hr burn that spot, about 6 ft above the insert, got plenty hot to the touch. Warm enough that I pulled the old Majestic insert out the next summer and replaced it with a pellet insert with its liner within the 6" stove liner. I suspect the 6" stainless liner was right up against the brick.

 

[bikepo]

Thanks again all. We are going ahead with finding someone certified to remove the existing liner, camera-inspect, and install a shiny new insulated one. I'll post back if there are any exciting findings.

 

[begreen]

Good plan. Keep us posted.

 

[bholler]

Thanks again all. We are going ahead with finding someone certified to remove the existing liner, camera-inspect, and install a shiny new insulated one. I'll post back if there are any exciting findings.

There is no need to be scared of pour in insulation either if it is done properly it is a good insulation. But hearing about the other things the contractor did i am not confident that it was done properly

 

[Lake Girl]

My silly question is that since the "fireplace" was added at a later day to make it look like a traditional fireplace (noticed the bench next to it), would it be worth the effort & cost to tear that whole corner out? No more second guessing what was there, what flaws there are, or some questionable install. From what you describe, I'd be freaking over family safety....

 

[Smoked]

This does make me happy that I chose or you guys convinced me to use insulated/preinsulated for both of my chimneys all the way. Even so, my brick above the lintel was very hot all the way up to the trim on my original install. Previously I shielded the tee and that helped. This summer, reading this forum convinced me i needed to do a block-off plate for my new basement install. I had plenty of material so I did one in both fireplaces while i was at it. I added liner insulation all the way down to the snout of the tees and have a bunch of Roxul in the damper area and right on top of the block-off plate. Mine was never hot enough that I could not keep my hand on it but it made me uncomfortable anyway. Scary to see that heat can transfer like that through masonry!! Hoping the insulted plate will kick some of that heat off of the snout into the room now!

 

[Lake Girl]

Forgot to mention earlier ... the vermiculite insulation is fine if left undisturbed. Since most of the vermiculite that was available in the US/Canada came from the Libby Mine in Montana, it is treated as asbestos contaminated. (broken link removed to http://www.epa.gov/retailindustry/buildings/insulationbrochure2-1.pdf)

 

[bholler]

Forgot to mention earlier ... the vermiculite insulation is fine if left undisturbed. Since most of the vermiculite that was available in the US/Canada came from the Libby Mine in Montana, it is treated as asbestos contaminated. (broken link removed to http://www.epa.gov/retailindustry/buildings/insulationbrochure2-1.pdf)

That depends when the product was installed yes there was a time when that was true. But for the last 15 to 20 years (i dont know the date off hand and dont feel like looking it up this mourning) all vermiculite is tested and safe.