Smoking Problems

How to "fix" a smoking chimney.

It can be a bit of a challenge to make some chimney's work: especially when it gets cold. Cold air is very "heavy". The column of air inside a chimney can be like a huge "cold-plug". It really does require a diligent effort to move this "cold plug" out of the chimney. It takes more time than some people imagine just getting a chimney to start "drawing." They need to understand that a warm air "siphon" must be created. This may require five or ten minutes of careful effort. The best way to make your chimney work is to take the time to establish a good draw.

Crack a Window

The first best trick to enable a chimney to draw is to open a window. Remember a properly drafting chimney is very much like a siphon. If the chimney has no available source of air it can not draft. It can even matter which window in the room is "cracked open." Having the window open is making available more air for the chimney. Helps over comes any negative air pressure in the house and having wind blowing in the window may pressurize the house forcing air up the chimney. Some of the things in your house that can cause down draft, pulling that cold into your house and making it even harder to establish a good draw, are exhaust fans, vented gas appliances, clothes dryers and already having second fireplace running.

Pre-heat the Flue

The next best trick to enable a chimney to draw is to: pre-heat the flue. This is the critical step. You must take up arms against the atmospheric-cold-blanket of heavy arctic air. Mother nature is bearing down with a vengeance on your chimney; you must take the time to create a miniature artificial environment: inside your own chimney. You must break through the cold plug of air clogging up your chimney, and then keep pushing until a warm air siphon is created, then your fireplace can burn majestically on the freezing cold winter nights!

Ten Steps to Success

1) Make sure the spark screen on your chimney cap is not clogged or obstructed.

2) Look up the chimney with a strong flashlight and check for obstructions.

3) Make sure the damper is propped to stay wide open.

4) Crack open a nearby window an inch or so.

5) Prepare to start a SMALL fire by crumpling newspaper under the kindling.

6) Roll up 5 or 6 newspaper "torches" to pre-heat the chimney's flue.

7) Light the newspaper torches one at time: hold them one after the other UP the chimney.

8) Spend 4-5 minutes pre-heating the flue with these "torches." Establish a "siphon."

9) Carefully light the kindling, and build up the fire slowly.

10) After the fire is going, and the siphon action is well established, close the window.

Possible Problems

There are a number of problems a chimney may have, which actually make establishing a good draw difficult. But, 9 out of 10 people who think they have "smoke problems" really don't. Most people just don't realize that they need to take more time to get their fireplace working in the first place. But, there are a number of possible problems that need to be considered.

Adding a Smoke-Guard

Sometimes, the opening of the fireplace is a little too big for the size of the flue in the chimney. In cases like this, smoke perpetually spills out into the room. There is a way to test to see if your chimney has this problem. Tape up a 4” strip of aluminum foil across the top of the opening of your fireplace. The object is to cut down the size of the opening of the fireplace, so that the flue doesn't have to exhaust so much incoming air. Use your fireplace several times with this temporary "smoke guard." If the 4” aluminum foil strip eliminates your problem, install a real Smoke-Guard.

Chimney Extension

If a chimney is too short, the siphon (draw) which must be created, is easily broken by wind changes, or other factors. A chimney needs to be a least 10-ft high. The best chimney's are between 12 and 16 feet high. If your chimney is less than 10 feet high, and a carefully established draw cannot be maintained for an extended period, you may need to extend your chimney.

Chimney Termination Heights

Minimum chimney height: If chimney is within 10-ft of the peak chimney must extended 2-ft higher than the peak. If the chimney is over 10-ft from the peak, the chimney should be 2-ft higher than anything within 10-ft horizontally. (NFPA 211). Sometimes nearby foliage needs to be removed. Remember that most types of smoking problems can be "fixed" simply by taking more time to establish a good draw.

Unused Fireplace Smokes while Another is being Used

Often a fireplace will smoke while another in the house is being used due to the "inadequate air supply". This problem can at times be easily solved by raising the flue height, 12-24 inches, of the fireplace used the most. And will in most cases solve the problem.

Call the Experts

If you need further advise about fixing a smoking chimney, call the experts. Whempys Chimney Services has over 20 years experience diagnosing, and fixing smoke problems. We are happy to help you with any chimney related problem.