How to stop fireplace smoke?

[beccasoons]

Hi, we have a very lovely fireplace in our house going to waste in this cold weather, I really want to restore it, but every time we light it, it works fine until its about to go out and then all the smoke comes inside, setting off fire alarms, and resulting in us having to open windows and doors. Slightly defeats the object of having a fire to heat up house. We've had it cleaned but the chimney sweep didn't seem to know why the smoke was coming inside the house, as it did the same thing after we had it cleaned. Can anyone help? Its a wood fire place, house was built in late 60's i think. Thank you.

[Dave-1]

Good Afternoon @beccasoons 

First up, welcome to the Bunnings community pages perfect thing to be doing a cold and wet day  

Do you know the last time you have had your chimney swept? This is what could be causeing the fireplace to bleed back smoke when the fireplace stops pushing heat up. If the neck of the fireplace (chimney) is constricted it will still allow smakoe/heat to go up and out with a drawing action caused by the heat. If its partially blocked then the draw effect will be less so and when the heat goes so doe sthe draw of the fireplace.

A Chimney sweeper is who i would be looking for in the first place. They will also be able to point you towards the appropriate trade if the fireplace needs repairs.

Dave

[JacobZ]

Hi @beccasoons,

Welcome to the Bunnings Workshop community, it is fantastic to have you with us.

That sounds super frustrating. 

Since you’ve already had the chimney cleaned and the smoke still comes in when the fire’s dying down, it’s likely a draft issue.

When the fire gets low, it doesn’t produce enough heat to keep the air rising up the chimney. If the flue cools too quickly, the draft can stall or even reverse, pulling smoke back into the room. This is pretty common in older fireplaces, especially if the chimney is wide or unlined.

Another thing to check is air pressure. If your house is sealed up tight or you’ve got exhaust fans running, it can create negative pressure and suck air down the chimney instead of letting smoke out. Next time you light the fire, try cracking a nearby window slightly. If that stops the smoke coming in, it’s probably a pressure issue.

It sounds like it might be worth getting a fireplace specialist to take a look at things like flue size, insulation, and airflow.

Let me know what you think.

Jacob

[beccasoons]

Hi Jacob,

Thanks so much for this response, I have been wanting to know the technical problem for so long. Our flue is quite wide, and its definitely not lined. We've tried opening a window whilst fire is burning and same thing happens. We also have an exhaust/fan under our house but is off at night when we light the fire. I think I might have to get a fire specialist in, but thanks ever so much for explaining clearly what could be the problem.

Becca

[Dave-1]

Afternoon @beccasoons 

Sorry 😕 I somehow missed that you had the chimney cleaned in your first post 😕 

Dave