My Stove Stinks - Literally! (Hearthstone Heritage 8021)

  • Active since 1995, Hearth.com is THE place on the internet for free information and advice about wood stoves, pellet stoves and other energy saving equipment.

    We strive to provide opinions, articles, discussions and history related to Hearth Products and in a more general sense, energy issues.

    We promote the EFFICIENT, RESPONSIBLE, CLEAN and SAFE use of all fuels, whether renewable or fossil.

Fasttrack

New Member
Sep 23, 2024
13
Southern NH
I know this is an impossible question to answer accurately but I figured I'd see what other people have experienced in case it helps me figure out my problem.

Every time I burn, I get a noticeable hot paint / hot plastic smell. It's unpleasant and is worse higher in the room (down low where the air is cool it's not really noticeable).

Full story below but the condensed version is this: the smell is coming from the gap between the top stones and the front cast iron edge. I've smelled all over the stove while it was hot (a comical undertaking) and determined it is pretty localized - it's not the stove pipe, the stones, the doors, the glass, etc. Basically just a line right across the front top part of the stove. There are no obvious signs of damage or contamination.

Does anyone know what hot / burning thinset smells like? I'm wondering if the front stone came loose at some point and the previous owners attempted a repair using a polymer modified thinset instead of a furnace cement.

Full story: I bought a used Heritage stove on FB Marketplace a couple of months ago and installed it myself. Had it inspected and all is good. The chimney liner is old but clean and I only needed a small stovepipe elbow to adapt the stove to the liner. (I initially thought the smell was from the paint curing, but that doesn't seem to be the case).

The stove is the old model before they improved the latches. The side door was fine and I won't use it, so no changes there. I did replace the front door frame, all the gaskets, and the baffle board was missing, so I installed a new one. (Also thought the smell might be the baffle board curing or the gasket cement curing but have since ruled those out). I also found that the two soap stones inside the firebox were loose, so I cemented those back down with high heat furnace cement. I followed the instructions for curing the baffle board and we had our first real burn yesterday, running for about 12 hours. The smell was just as bad as the first several short / small fires. It doesn't set in until the soapstone is really good and hot and it's definitely localized to the top front portion of the stove.

I bought this from a guy who apparently bought it to install in a vacation house / retirement house he was building. It sat on storage for several years and he ended up sustaining an injury that made splitting, stacking, and carrying firewood a non-starter so, once he completed the house, he installed a pellet stove and sold this one.

Any ideas? Anyone run into this kind of thing before? It doesn't seem to be getting better with burning or I'd just let it cook off...
 
Does anyone know what hot / burning thinset smells like? I'm wondering if the front stone came loose at some point and the previous owners attempted a repair using a polymer modified thinset instead of a furnace cement.
If that was done, it was in error and it is suspect. Hearthstone makes and sells a special refractory cement for these repairs. While looking the stove over, make sure the baffle was properly installed too.
 
Update:

In case anyone else stumbles across this thread, it turns out the "problem" was the baffle board. After two more days of burning at more or less full output (and the windows wide open!) the stove no longer stinks. Seems the baffle board just took a little longer to burn off all the binder than I anticipated. I also didn't expect it to smell so strongly in the house since there is never any smoke odor and there is a nice strong draft. Something about the vapors from the baffle board binder must just diffuse through things in a way that ordinary wood smoke does not.

Good news is that we're now back to burning as usual and couldn't be happier!
 
  • Like
Reactions: Todd
I'm having a tough time figuring out how this could be the baffle board. Any smell from the baffle board and internal components should have remained in the firebox and have been pulled out by the vacuum of the draft. It sounds more like something that was used externally on the stove body was the culprit and now has baked in. What was used for the door gasket adhesive? Was a glass gasket adhesive used?
 
I also had a hard time believing it was the baffle board but the smell seemed localized to the joint between the top soapstone pieces and the cast iron frame of the stove. The cast iron smelled "hot" but normal and the soapstone further back smelled "hot" but normal. It was just that crack that smelled, despite having no appearance of contamination or alteration. That is immediately above the baffle board... but, as you said, I struggled to understand how any of the baffle board smell was making it into the house when the wood smoke was not. Even opening the glass door rarely lets a puff of smoke in because the draft is so good...

Interestingly, towards the end of our extended bake out period, I did notice that the smell returned briefly when opening the glass door and seemed stronger inside the stove (hard to tell without sticking my head in the fire!). But the smell that was stinking up the house was noticeably different than the very slight odor I could detect when sniffing the gaskets on the door when it was open 🤷‍♂️But you're right, it could have been something else entirely...

To answer your question: the door and glass gaskets were replaced using a kit from Hearthstone. The gasket material was the typical graphite impregnated fiberglass rope, although it did come with a pre-applied adhesive backing. The gasket cement (used in addition to the adhesive backing according to Hearthstone) also came with the kit, "Imperial" brand like this one:

 
It may remain a mystery but I'm very glad to hear that whatever it was has dissipated. Enjoy the warmth of that beauty!