What could be causing a pile of stuff on top of my wood insert over night.

[Riverside_eng]

Had two smokey mornings in a row where after the fire is good and hot I start to smell and see a bit of smoke.

Both times when investigating I found burned pellet size items in a section on top of the stove. It is next to the flexible flue pipe so burning makes sense but given that there is a level of sheet metal over it not sure how stuff is getting there from above in the masonry chimney?

Best I can figure is a repeated poor attempt by a soon to be deceased rodent on storing food.

Alternative would be insulation moonshotting through the small gap in the sheet metal.

Any ideas what would be the cause? It's not at start of a fire or end, it's when the flue pipe has gotten hot enough to burn off what seems like a notable pile of something that showed up over night.

(Will need to look closer on subsequent mornings before getting the insert going to see what it looks like pre burn or if it hopefully stops on it's own.)

 

[PaulOinMA]

Little more information on the details of the install? Old, residual creosote flaking off chimney? Do you ever hear anything falling in the chimney?

 

[kennyp2339]

Is your liner insulated or plain stainless steel going up the chimney?

 

[Riverside_eng]

Little more information on the details of the install? Old, residual creosote flaking off chimney? Do you ever hear anything falling in the chimney?

4 year old install.

Wood burning fireplace insert.

Cleaned professionally yearly in early fall.

Unlined steel flexible liner

Have not heard anything falling but this has been over night.

What I could see burning is under where pipe seems to be attached to collar on stove and below a level of sheet metal.

Picture attached in middle area on right is particulate/pellets which were burning.

 

[kennyp2339]

More then likely its little creosote pieces

 

[PaulOinMA]

Sounds very familiar now. I have an insert that was installed in 2018 after getting rid of a Wilkening in an unlined chimney. My chimney guy cleaned the chimney before dropping the liner and said that I will have some residual creosote drying out, flaking off, and dropping for a few years.

I remove the surround and vacuum it up around and on top of the insert when I do the liner cleaning. No biggie. It's not much at all. He said it will be less every year for a few years, and that's what I have observed.

If your install has been four years, you may want to vacuum things up around and on top of the insert

 

[Riverside_eng]

Showed my wife the picture, it's shaped like our dog food so probably that solves the mystery.

 

[stoveliker]

I'd be a bit more concerned if you have smoldering stuff falling down on the outside of your liner. You can assume it's previous creosote (which I think indicates an improper cleaning before the liner went in), but what if it's not?

What if your liner is damaged (has a hole)?

(And regarding dog food - how'd that get there.)

All I'm saying is that you seem to want to conclude it's safe, but you don't really know. That's a risk I'd rather not take in my home.

 

[Riverside_eng]

I'd be a bit more concerned if you have smoldering stuff falling down on the outside of your liner. You can assume it's previous creosote (which I think indicates an improper cleaning before the liner went in), but what if it's not?

What if your liner is damaged (has a hole)?

(And regarding dog food - how'd that get there.)

All I'm saying is that you seem to want to conclude it's safe, but you don't really know. That's a risk I'd rather not take in my home.

At this point I am cleaning it out, then will see what shows back up.

Given the location I am doubtful it is creosote given the likelihood of it showing up there vs a leve above where it would be directly exposed to items falling from chimney.

Also setting traps because mice are always possible in an old house. We have found dog food previously then aggressively trapped to resolve the issue for that winter.

My wife pointed out it smelled like burnt food specially and the pellet stuff looks like our dog food.

I can inspect the bottom of the liner which is packed with Rockwool around it, if no gaps are there it would have to be teleporting to get through Rockwool and a layer of sheet metal. So it would have to be animals putting something there or something coming in from behind or in front of the stove where the shrouding is open to air.

 

[Riverside_eng]

To be clear here is the now fished out stuff and dog food side by side.

(See sealed packs because other than food in dogs bowl we don't allow open containers to avoid mice, but our dog is a lazy eater)

 

[PaulOinMA]

This has been a bad year for mice here in Marlborough. Caught more than I have in years. Another person told me the same.

 

[Bad LP]

I’ve killed more mice this fall than every before.

 

[BigJ273]

Sure looks like the dog food to me

 

[Riverside_eng]

Sure looks like the dog food to me

All mice and no creosote in the traps this morning.

Did a full inspection of the stove a few times and fired it up with no ill effects.