Strange material leaking from the stove

[Green]

Does anyone know what this material coming out of the side of my stove is? Its not ash..

 

[Sue Ellen]

I'm wondering if its relevant to state what fuel you are using?

 

[mct1]

Possibly vermiculite? It was previously used in house insulation, and can sometimes contain asbestos. For this your house would need to be at least 25 years old as it wasn't in use after the nineties afaik.

 

[Monbretia]

Looks like vermiculite, often used to fill in gaps around fire backs in open fires, maybe it's filling in around some pipes behind stove. Whatever about not being used since nineties every time I have my chimney cleaned the guy says I should replace the basically attic insulation like stuff (fireproof) behind my fireback with vermiculite or maybe he's using an old generic name for some modern form of it?

 

[Green]

@Sue Ellen I used a mix of kiln dried logs and eco smokeless coal.

 

[ClubMan]

Vermiculite - Wikipedia

en.wikipedia.org

As loose-fill insulation​

Exfoliated vermiculite treated with a water repellent is used to fill the pores and cavities of masonry construction and hollow blockwork to enhance fire ratings (e.g. Underwriters Laboratories Wall and Partition designs), thermal insulation, and acoustic performance. Expanded vermiculite has also been used as thermal insulation in the attics and walls of houses and in water heaters, fire safes, stoves, furnaces, and refrigerators.

 

[paper-folder]

Agree that it looks like vermiculite. Most likely a flexible metal flue liner was installed when the stove was fitted, and vermiculite was used to backfill the space between the outside of the liner and the original flue pipes. Highly recommend that you get someone to check this out for you, as the chances are that there were three or four bags of material used originally, so it's just going to keep coming until it's sorted.

 

[Forumuser]

Vermiculite for sure. It was used as insultation for your flue pipe. The flue gathering might have cracked and the stuff will keep coming now all the time.
You need to call in the folks who installed your stove.