Some smoke leaks or puffs out of your stove or fireplace into your home instead of being vented exclusively to the great outdoors. What's the cause and how can you fix it?

 

Problem: Smoke puffs out of the stove or fireplace during use

The culprit is usually inadequate venting or a downdraft.

 

There are two main causes and remedies:

 

The external outlet of the chimney or flue doesn't have a clear passage of air over it. This may be because it's has become blocked by trees or other tall plants that have grown up around it, or a bird or other animal has built its nest inside your flue. Solution: remove the obstructing branches, foliage, or nest. Alternatively, the problem may be that the chimney simply isn't tall enough, perhaps because a newly-added extension or garage rises above it. Solution: increase the height of the chimney or flue.

Winds, especially high winds, may blow smoke back down the chimney. Solution: check the cap on the chimney (if there is one), and if necessary replace it or add an anti-downdraft cowl. However, make sure that this doesn't reduce the effective aperture of your chimney. If it does the solution may be to install a motorized draft inducer (typically $1,000 to $2,000) that fits to the top of the chimney or flue and literraly sucks the smoke out of it.

 

Problem: Smoke seeps out of the stove or fireplace especially when first lit, or when the stove doors are open

There can be a number of reasons for this and you need to work your way through the various possibilities, starting obviously with the easiest and cheapest to check.

 

If smoke leaks out when starting a fire the problem may be that there isn't a big enough pressure difference between the inside and outside of the house to get a draft going right away; it's a problem that tends to be worse in cold weather. Other things you might try as a remedy are closing windows and doors (especially the basement door), and turning off kitchen or bathroom exhaust fans.

Smoking escaping from the top of a fireplace might point to an undersized chimney or an oversized fireplace; if the latter, a smoke guard, which cuts down the opening of the fireplace, might give a quick solution.

A smoking stove may point to the need for some maintenance work. For example:

 

    - If your damper won't open fully, have it repaired or replaced (a fully-functional damper is crucial).
    - If your chimney or flue has a build-up of soot or creosote, have it cleaned or clean it yourself.
    - Check there isn't a build-up of soot on the baffle plate inside the stove.
    - Check the joints in the stove and flue. They may need resealing with fire cement.