First post, appreciate all the help I've got through the years and had a quick question.

[Joeycoey]

Replacing an old oil burning furnace with a wood burner, chimney was cleared for use, but was advised to replace the thimble as it had some cracks. Now my question is, is the clearance for oil burning appliances different than wood/solid fuel? I'll try and attach a photo, but the brick clearance around the thimble is only about 4 or 5 inches in any given direction, as opposed to the 12 I've cut out. Yes I plan on correcting this, my question is was this a hack job or were these old school clearances acceptable then?

 

[begreen]

That clearly is not appropriate for a wood stove. There needs to be at least 12" of brick between the thimble and surrounding wood. Otherwise an insulated thimble is required. It makes me suspect there are other issues. Who cleared this chimney?

 

[Joeycoey]

Local chimney cleaner, when they looked it over I didn't have this opened up I should add.

 

[begreen]

There are several factors that will determine suitablility besides the condition of the clay flue liner. For a wood stove, if this is an interior chimney, it should have 2" clearance all the way up through the roof. It also should be sized correctly for the stove. Is the ID of the clay tile liner known?

 

[Joeycoey]

It is an exterior chimney, clearances were said to be okay both for the chimney itself and the airgap between liner and block. The ID when measured thru the thimble is 6.5 in both ways, square.

 

[begreen]

Then it could be that all this will need is an insulated thimble. There are a few companies making them. There are a couple of brands mentioned in this article.

Chimney info - CHIMNEY - PASSING A CHIMNEY THROUGH THE WALL

DON’T Just “Do it” - Placing a wood stove into an existing masonry chimney could be hazardous to your health and house. Read this to learn more. One of our biggest problems occurs when a customer enters the shop and states “I have an existing woodstove into a masonry chimney - I’d like to...

www.hearth.com

Insulated Chimney Thimble for Thimble and Wall Pass Thru Installations - Rockford Chimney

An Insulated Chimney Thimble protects the wall from overheating where the flue pipe passes through. Includes installation instructions. Free shipping.

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