Flue has trouble drawing when it's windy.

[lwood]

Only when it's windy do I have trouble at start-up of the flue won't draw. Anybody have a wind-proof flue cap?

[mickyD]

Re: Flue has trouble drawing when it's windy.

Hi Iwood,

I have a supposed wind proof flue cap which is a circular piece of aluminium surrounding the flue cap. I have no doubt that it does prevent some wind from going down the flue. From what I have observed in my oven on windy days is that the wind blows into the oven chamber and disrupts the air flow which allows some smoke to escape out the front. As you said, it happens on windy days mainly on start up. I think due to the fact that on start up there may not be enough heat to have a strong enough draw to fight the gusts of wind that may blow in. Once the fire is roaring though, there?s not much stopping it.

Cheers,

Mick

[nissanneill]

Re: Flue has trouble drawing when it's windy.

Never experienced that with my flue and flue chamber which is larger than normal
My first thought when reading your post was that your flue is too small, probabl6 6" I guess and the chamber thsat catches the smoke and funnels it into the flue is also too small and not performing as it should.
The only time I have ever had smoke coming out of the front arch was when I was using a leaf blower on full chat to get the fire going with greener wood. Normally if rces the smoke and hot gasses directly up the 12 foot flue.

Cheers

Neill

[brickie in oz]

Re: Flue has trouble drawing when it's windy.

I had the same problem yesterday, we had some horrible wind blowing from all directions and start up was a bit of a problem but once going it was ok.

I did notice that there was less of a problem when I had the blast door on and the damper slightly closed to block off part of the flue.

[lwood]

Re: Flue has trouble drawing when it's windy.

Wind can't blow into the oven because the oven is partially enclosed and protected. I have an 8" flue and the gases are water-falling down the flue. This occurs mainly at start-up but strong winds can cause the problem, during regular operation, to a lesser degree. Maybe I will just have to live with it.

[brickie in oz]

Re: Flue has trouble drawing when it's windy.

Wind can't blow into the oven because the oven is partially enclosed and protected.

Can it blow down the flue though?
Have you got a pic of the top of the flue?

[lwood]

Re: Flue has trouble drawing when it's windy.

Yes, it can blow down the flue. All I have on top of the flue is a conical lid with about 2 3 inches btw the lid and the pipe. No pic

[brickie in oz]

Re: Flue has trouble drawing when it's windy.

Yes, it can blow down the flue. All I have on top of the flue is a conical lid with about 2 3 inches btw the lid and the pipe. No pic

A pic would tell if there was any obstruction near by that was causing down drafts when windy.

[brickie in oz]

Re: Flue has trouble drawing when it's windy.

Is this your flue?
From your facebook page.

[lwood]

Re: Flue has trouble drawing when it's windy.

Ha Ha Brickie...good eye. No that's not my oven flue, it's my fireplace flue and it is way too short, have to lengthen it cause it does the same thing. My oven flue is much taller (3m) and round, but has the same type of cap.

[brickie in oz]

Re: Flue has trouble drawing when it's windy.

have to lengthen it cause it does the same thing.

That was going to be one of the suggestions.

Maybe its the lack of space between the flue and the cap that is restricting the flow?
The other thing would be down drafts coming over the top of roofs.

[lwood]

Re: Flue has trouble drawing when it's windy.

Thanks brickie, what about the cap? I'm thinking that some kind of perforated metal or screen in the space btw the flue and cap.

[brickie in oz]

Re: Flue has trouble drawing when it's windy.

If the cap was wider and higher up it would help let the gases out, the surest way to restrict a flue is to have the restriction right at the top.

[lwood]

Re: Flue has trouble drawing when it's windy.

Agreed, will take of the cap and see what happens.

[lwood]

Re: Flue has trouble drawing when it's windy.

let me take a pic of the other flue.