Wood burner

[Earlybird00]

Does anyone have a wood burner in their kitchen where an external extractor fan is also located? Been told its not possible as it can draw CO2 out of the stove. Is this the case?

I can see that it could be a problem. The extractor fan draws air out of the room; the stove works by drawing air out and up the chimney. If both are running at once and the extractor is more powerful then you are going to have problems with the fire, air might be drawn from the fire into the room, and it might affect burning which would make it a carbon monoxide issue.

Could get a stove with an external air inlet, these are also more efficient because they don't cause more cold air to come in when the stove is on.

I have and it's never been an issue. I used to open the window a little bit to draw extra air in, but it makes no difference.

I think it depends on how sealed the house is, the stove output, extractor power and the draw on the flu.

I have a 5kw with a powerful draw. The house is pretty sealed house and the extractor is nothing special.

Is it correct that if 5kw you need a 50p size air inlet for every extra KW!? Or something along those lines...

that if -over- 5kw

This was mentioned when I built my house but decided not to be an issue. I have a mechanical ventilation system and 2 wood burners.

I have just had a stove fitted in a large open plan kitchen, I am currently unable to use it!

Be very careful, I won’t go into the details of how we ended up having this discussion after the stove had been fitted!!

I pointed out the extractor fan to the installer, he did a smoke pellet test,
The room is large , 10.5m in length by x 4.4 W open plan with a over hob built in extractor.

The stove is 7m away from the fan. Flue warmed, smoke pellet put in the stove and drawing nicely up the flue, extractor turned on, it emptied the smoke out of the stove and into the room immediately. That was with one wall vent already installed.

He then had to repeat the test and open a window until it stopped drawing the smoke from the stove, then do a calculation to determine the size of the second required wall vent.

Needless to say I am frustrated this wasn’t discussed before fitting, more importantly, however, I want all you people to know what I saw with my own eyes and imagine that is toxic gas leaking into your room.
I will do whatever is required to make it safe, cutting multiple holes in the wall wasn’t part of the plan though.

@JohnJohnlegizmo I’m not saying that your situation isn’t a problem and I’m sorry to read of it, but in reality when your log burner is lit the heat it produces pulls masses of air up the flu. Infinitely more than during a smoke test. If you were to do your test with an actual fire I doubt the draw on the extractor would impact on the fire. It might however be an issue when lighting it before the flu is hot. Your stove fitter may have used a blowtorch to warm the flu before the smoke test but that wouldn’t get it very hot at all. In short I wouldn’t worry too much. I’m presuming that your stove is about 5kw considering the size of the room.

Indeed he did. The problem is he won’t sign the stove off.
Ultimately that’s up to him, and he says he can’t sign it off whilst it drawing smoke out like that. I think this should have been considered as part of the original assessment they did. He now wants to put an additional vent in.

We are waiting for another stove fitter to get a second opinion. Our difficulty is that the stove is at the rear of the room after a huge building project and freshly plastered walls - nowhere to put vents. If they don't sign off then our only option I think is to change our mechanical extraction by putting the filters in and recirculating. I agree that if it was lit properly there would be no issue with the smoke going up the chimney but this doesnt seem to be how they access it