Second Story Interior Wall Warm to the Touch

[MegCog]

Hi guys, when our wood stove insert was first installed in the main story living room, the wall in our bedroom and the wall in our daughters' bedroom that wrap around the chimney (on the second floor) were warm/hot to the touch. Our daughter came down crying one night, saying the wall was hot and it frightened her. Does anyone know what would cause this?

 

[gthomas785]

Do you have a liner / is it insulated?

 

[brenndatomu]

Sounds like there may be some insulation or clearance issues there...I'd not have another fire in the stove until you can get a chimney professional out to check it out.

 

[gthomas785]

Also, how "hot" is the wall getting? The wall around my chimney on the second floor gets faintly warm with the stove operating but never above 80-85 degrees as measured with an IR gun.

 

[MegCog]

There is a liner, but not sure if it's insulated - I'm guessing not.

We have had a lot of issues with our stove since it was installed almost 2 years ago. After we first got it, we started to have smaller fires to preserve wood (we were going through wood really quickly because of air leaks in the stove) and we were just wondering if that might have fixed it and if it could have been caused by overfiring the stove...

We also did have a chimney sweep come out to look at our stove after one burn season and he said everything was really clean and he didn't need to clean it. Would he have noticed if something was wrong on a typical inspection?

We haven't noticed it as much lately so, as we were discussing some of the stoves other issues and its history, we started wondering what might have caused that in the first place and why it seems to not be as much of an issue now. Our first thought was that we were building larger fires then than we are now.

 

[MegCog]

We didn't measure the wall temperature at the time. I could try building a larger fire now to try to recreate it and see if I can get a reading. When it first happened I don't think we had the heat gun yet.

My husband guesses it was due to us building such large fires and with having the air leaks feed the fire even more, the strong draft might have taken a ton of heat up the chimney and warmed the chimney more than usual?

We were just wondering the types of things that could possibly cause this and if there might be another explanation or if that explanation would make sense.

 

[brenndatomu]

There is a liner, but not sure if it's insulated - I'm guessing not.

That would be my guess too...many stove shops and sweeps seem to like to forego the insulation, but as @bholler can attest to, most liners really need insulation, or at the very least, can benefit from having it.
In my mind, insulation on the liner is a little insurance that helps me sleep better when I'm burning in the stove!
If it was warm enough for your daughter to be concerned about it, I'd say it likely was too warm...but only way to know for sure is to fire up and check the wall temps, report back.

 

[gthomas785]

It's possible. I know it's an insert but is there any way you can install a probe to get a reality check on the flue gas temperature? I know we were originally overfiring our stove and liner for a while until I got my flue probe installed because we simply didn't know how hot it was getting.

Also try to find out if the liner is insulated. You should be able to see some insulation by removing the surround and poking around, but if there's a block off plate it could be a bit more involved. That is another way to get some peace of mind.

 

[MegCog]

Ok so if the liner is not insulated, then that is something we ought to consider? What are the benefits? What is @bholler's story about the need for insulation?

We are actually supposed to get our insert unit replaced in the coming weeks/months because of the mountain of on-going issues we have had with it, so then might be a time where we could more easily "poke around" and check everything out.

I am relatively sure that we likely overfired our stove for quite some time because of the inability to control the air with the stove not being airtight. We also were not getting the heat we were expecting (my guess due to the air leak causing a strong draft that sucked the heat out of our house before we could appreciate it), and our installer had told us just to build hotter fires so for awhile we were building massive fires with no real ability to choke it down.

Now that we are getting a replacement unit, I am trying to do my due diligence to make sure we have all the functionality that we ought to have and that all the pieces are in place for us to (safely) get heat from our stove that actually can be felt in the house. I am nervous that over the course of about 1-2 burn seasons of too much air getting in the stove, that some damage may have been sustained to the other parts of the system. I don't know enough about what goes on behind the scenes of my wood stove to know what to check and what to worry about.

 

[brenndatomu]

Ok so if the liner is not insulated, then that is something we ought to consider? What are the benefits? What is @bholler's story about the need for insulation?

In my opinion, insulation on the liner is not an option. Many chimneys would not pass a proper inspection without it, and the liner will stay cleaner with insulation on it. And like I said, for me, even though my chimney absolutely requires insulation on the liner (my clay liner is gone) for me it is also just good "sleep better at night" insurance.
Do you know if your chimney still has a good clay liner in it?
Even if it does, so very many (most) chimneys are not built to the letter of the law as far as CTC (clearance to combustibles) and without getting into some major demolition, there is often no way to verify if the proper CTC is there, or not. It's just easier/cheaper to spend an extra few hundred $ and do insulation on the liner...you'd have to have your stove or chimney guys look at your liner to see if insulation could simply be added to it...if so, to me its a no brainer decision.
If you search around, @bholler has plenty of pictures posted here from chimneys he's worked on that had things done improperly on the chimney and there was charred wood framing inside once opened up (there should be no wood framing in the chimney!)

 

[begreen]

My husband guesses it was due to us building such large fires and with having the air leaks feed the fire even more, the strong draft might have taken a ton of heat up the chimney and warmed the chimney more than usual?

If the liner is uninsulated and resting against the bricks and tile in the chimney, the heat will be transmitted through the brick. It's not too serious if the wall temp is in the 120-130º range, but more concerning if in the 170º+ range. But this is only where you can measure it. The temperature elsewhere is a guess. The potential for pyrolysis to develop over time can be high. This is why an insulated liner is required unless there is a 2" clearance for the chimney from any and all combustibles all the way up through the roof.

This could be an issue with the way the stove is run or the condition of the stove. What stove make and model is this? What concerns are there about the stove leaks?

 

[Ctwoodtick]

If a second story wall is hot or even quite warm I’d be concerned that something is not right. I have access to my masonry chimney throughout most of its height and it doesn’t get very warm. Warm, but not close to hot if that makes sense. My liner is insulated, but I used to have it not insulated before I decided to have it reinstalled by somebody who actually knew what the heck they were doing. But honestly, prior to the liner being installed with insulation, I don’t recall my masonry chimney, getting warm during regular used to the point where I was concerned,. That pyrolysis concept is definitely a thing to be concerned with, but most definitely if you have a chimney fire, and the installation is not proper, you could be looking at a very serious problem.