Is this unused thimble a problem?

  • 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.
  • Hope everyone has a wonderful and warm Thanksgiving!
  • Super Cedar firestarters 30% discount Use code Hearth2024 Click here

danham

Burning Hunk
Jan 12, 2012
169
Cape Cod, MA
When we bought our house, there was an open two-sided fireplace and a coal stove in the basement. Our insurance company demanded removal of the coal stove, which we readily agreed to with the sellers as we planned to put an insert in the fireplace (see my forum icon). That left an open thimble in the basement, which they stuffed some Roxul into.

The insert is connected to a liner which extends all the way to the top of the chimney. The other flue in that chimney is used by a gas water heater and hot air furnace. We have had no problems, but something I saw online about sealing off unused thimbles got me wondering. I bet this was really unsafe when there was an open fireplace and coal stove (CO anyone?), but can't see any way that would be a problem with this setup. Your thoughts?

-dan
 
When we bought our house, there was an open two-sided fireplace and a coal stove in the basement. Our insurance company demanded removal of the coal stove, which we readily agreed to with the sellers as we planned to put an insert in the fireplace (see my forum icon). That left an open thimble in the basement, which they stuffed some Roxul into.

The insert is connected to a liner which extends all the way to the top of the chimney. The other flue in that chimney is used by a gas water heater and hot air furnace. We have had no problems, but something I saw online about sealing off unused thimbles got me wondering. I bet this was really unsafe when there was an open fireplace and coal stove (CO anyone?), but can't see any way that would be a problem with this setup. Your thoughts?

-dan
It is required by code to seal off any un used thimbles before installing a liner
 
Thanks. What risk do I run if I put off having it sealed until spring chimney cleaning?
 
Thanks. What risk do I run if I put off having it sealed until spring chimney cleaning?
If the chimney has a proper insulated liner in it and you stuff the crock with insulation probably not much risk
 
  • Like
Reactions: danham