Why does our house fill with smoke everytime we start a fire?

Question

We have had our chimney cleaned and inspected, there were no problems. We heat the flue befor we light the fire to create an updraft. Cannot understand why the smoke fills the house and does not go up the chimney.

Answer 1

What you have is a differencial pressure plane that is higher than the fireplace, (or woodstove), whichever you have.

This causes a negative pressure. All houses have pressure planes. It is caused by hot air rising and slowly leaking through the roof, meanwhile cool air being drawn in lower, through the foundation or floor. This is a natural process and it doesn't matter how much insulation you have, its gonna happen.

This problem is compounded when you have an exterior chimney. Even if you heat it before lighting the fire, the exterior chimney has a pressure plane of its own which causes negative pressure.

The lower portion of the pressure plane is under negative pressure and draws air from its easiest source, which could be your chimney.

The easiest, quickest way to solve this is to open a window near the fireplace when you light it. Close it once the fire gets going as once the chimney gets hot, it should not backdraft.

Answer 2

Did you open the flue??? That's usually the reason. Another possibility is that the chimney is not "drawing" or pulling air from the room into the fireplace and up the chimney. You may need to create a draft, at least temporarily, by cracking open a window so the fire can suck in the necessary air. Modern houses are often so well insulated that there is insufficient draft for a fireplace without opening a window.

Answer 3

You don't have enough draft. Light a match near your chimney the flame should be drawn up into your chimney. If it is not you have a draft problem. If you have an air tight house there may not be enough air to make the smoke rise up the chimney.

Also is there a damper in the chimney that is not opened.

Another might be the height of the chimney compared to surrounding structures.

You may need to check with a contractor who installs fireplaces.

Answer 4

If the chimney draft works ok once the fires hot, then you know you don't have enough draft when the chimney's cold. A long term solution is to have a new flu liner installed in your chimney. Also, try opening a window to help the draft.

Answer 5

I assume your talking about a fireplace. If so you probably need more of a draft going up the chimney. First start by having it cleaned. Then if you can add to the flue extend it up higher.

Answer 6

If you have a free standing stove, Is the stove pipe stoped up, Is the draft open, Is the chimney at least 2 feet higher than the roof? Sometimes weather condition's will do that to.

Answer 7

Notice if your central heat is on when this happens. You have to have a draft out of the flue to let the smoke escape. If air is being pulled in, the smoke is going to follow the draft.

Answer 8

You need a draft to get rid of the smoke and also a relief vent to bring in air for the furnace to burn, plus a combustion air intake. If you have alternate heating system it could be choking the air in the house

Answer 9

Be sure the damper is open and slightly open a window at the far side of the room/house to provide air so the fire can draw properly.

Answer 10

you may have a stronger draft inside the house than the one in the flue, which would suck the smoke into the house. check your windows and attic for seals and drafts.