This Article has been approved by our on staff NFI Certified Specialists & Master Hearth Professionals

A fireplace that allows smoke to back puff into the room is a nuisance and a downright danger.This is because the smoke carries odorless but deadly carbon monoxide. Diagnosing the cause of your back puffing is essential to finding the most efficient and cost effective solution to cure your smoking fireplace.

Why does my fireplace smoke when I try to light it?

If your fireplace only smokes when you first light your fire, the solution is usually simple and free. A lot of times, you just need to warm up your Chimney’s flue before you light the fire. An easy way to warm up your chimney flue is to roll up a piece of newspaper, light one end like a torch and hold it up inside your fireplace as high as you can and then immediately light your fire. The pre-warmed chimney flue will ensure the smoke goes up the chimney instead of back puffing into your home.

If warming your chimney flue does not cure your smoking fireplace when you try to light the fire, check and make sure all of your windows are closed, fans are off, and the clothes dryer and furnace is off. If this does not work try closing doors in the home to reduce the air volume especially a basement door. This will also help heat your chimney flue prevent back puffing while starting a fire in your fireplace.

Why does my fireplace smoke when it's windy?

If your fireplace only smokes on windy days, the most common cause is related to a downdraft created by high winds. Chimneys that are too short, over-sized flues and the absence of a chimney cap can be problem areas that cause downdrafts during high winds. To fix this type of problem, you can use a flue stretcher to add length to your chimney, or you can use a chimney cap that is specifically designed to deflect wind and suck the smoke out of the chimney such as a VacuStack Chimney Cap.

Be careful that you don't undersize your masonry flue by adding one of these caps. If you can't find a chimney cap that will not reduce your flue size, or adding a chimney cap does not cure your smoking fireplace, an Exhausto Fan will do the trick.

Why does my fireplace smoke intermittently?

A fireplace that smokes sporadically with no specific pattern can be caused by anything that would affect the air pressure in your home. This includes exhaust fans turning on and off, doors opening and closing, open windows (especially on a second story) clothes dryers or even the sitting of a house in relation to a hill, other buildings, or trees. Using a make Makeup air kit to reverse the negative pressure in your home is an effective solution to a fireplace that smokes intermittently. The Makeup air kit will force air into your home which will cure your smoking fireplace.

Why does my fireplace smoke when I try to light it?

If your fireplace only smokes when you first light your fire, the solution is usually simple and free. A lot of times, you just need to warm up your Chimney’s flue before you light the fire. An easy way to warm up your chimney flue is to roll up a piece of newspaper, light one end like a torch and hold it up inside your fireplace as high as you can and then immediately light your fire. The pre-warmed chimney flue will ensure the smoke goes up the chimney instead of back puffing into your home.

If warming your chimney flue does not cure your smoking fireplace when you try to light the fire, check and make sure all of your windows are closed, fans are off, and the clothes dryer and furnace is off. If this does not work try closing doors in the home to reduce the air volume especially a basement door. This will also help heat your chimney flue prevent back puffing while starting a fire in your fireplace.

Why does my fireplace smoke when it's windy?

If your fireplace only smokes on windy days, the most common cause is related to a downdraft created by high winds. Chimneys that are too short, over-sized flues and the absence of a chimney cap can be problem areas that cause downdrafts during high winds. To fix this type of problem, you can use a flue stretcher to add length to your chimney, or you can use a chimney cap that is specifically designed to deflect wind and suck the smoke out of the chimney such as a VacuStack Chimney Cap.

Be careful that you don't undersize your masonry flue by adding one of these caps. If you can't find a chimney cap that will not reduce your flue size, or adding a chimney cap does not cure your smoking fireplace, an Exhausto Fan will do the trick.

Why does my fireplace smoke intermittently?

A fireplace that smokes sporadically with no specific pattern can be caused by anything that would affect the air pressure in your home. This includes exhaust fans turning on and off, doors opening and closing, open windows (especially on a second story) clothes dryers or even the sitting of a house in relation to a hill, other buildings, or trees. Using a make Makeup air kit to reverse the negative pressure in your home is an effective solution to a fireplace that smokes intermittently. The Makeup air kit will force air into your home which will cure your smoking fireplace.

Why does my fireplace smoke all the time?

Design or construction error - A common design flaw that will cause your fireplace to smoke all the time is that the chimney is too short and doesn't effectively draw smoke away from the fireplace. A flue stretcher can be used to add length to your chimney. Another design error that might be causing your fireplace to smoke is that the smoke chamber if too small, either by width or height. If this is the case, those parts should be replaced to remedy the situation. If neither of these issues seems to be your problem, you may want to consult a professional to inspect your chimney.

Restrictions - Check for restrictions. Make sure your damper is fully open and not jammed. You'll also want to remove the cap and look inside of your chimney to make sure it is clear of debris. Even spider webs in flues that have been unused for a long period of time can be restrictive and cause the fireplace to smoke.

Pressure differential - A quick and easy way to test whether or not a pressure differential is causing your fireplace to smoke is to take a lit candle or incense stick and hold it up to the throat of your chimney. If the smoke goes up the chimney, you've got a good draft going and pressure differential is not your issue. If the smoke from the candle or incense stick blows back into the room, this indicates that there is a downdraft in the chimney. This means the room is too negatively pressurized and the easiest way for makeup air to replace the air being lost or exhausted somewhere else in the house is down the chimney. You can also neutralize the draft by opening a window or door, or turning on a fan or furnace in the house.