Chimney Extensions

[Phil111]

Hello all,

I current have a 24" chimney and i am informed that i should try to extend the chimney length as i am having problems with the draw from the burner. I was wondering about putting an extension on the chimney or looking for fittings to extend, but there seems to be very little on the market or information available. This is an initial enquiry into seeing what is possible and legal. Any help or advice is much appreciated.

Thanks

Phil

[rusty69]

A little more information required. What burner is it? What is the internal flue length/diameter?What are you burning? 

Edited September 11, 2019 by rusty69

[ditchcrawler]

I have a 2 foot stainless extension that fits in the top of my chimney for the odd occasions I have the back cabin stove alight. I had it made, it just slips about 2" into the top of the existing chimney 

[Arthur Marshall]

I'd check the bottom of the flue isn't blocked with gunk first, where it sits on the collar on the fire. That what usually blocks the draught, and a chimbley extension won't help that. 

[blackrose]

I think you'd need to add a long extension to your chimney to actually see a difference in draw. It's a bit impractical on a boat. Once you get to the point that it did make a difference you might need to insulate the chimney because on cold nights that long chimney might be adversely affected by cooling flue gases. It doesn't really affect short boat chimneys. 

 

I think the best thing you can do if you haven't already is make sure your chimney, flue and stove, including any baffle plate at the top of the stove is well swept and free of excessive soot. When I sweep my chimney/flue and clean out my stove it always improves the draw.

 

Get yourself an ash scraper to clean the baffle plate (assuming your stove has one).

 

https://www.amazon.co.uk/dp/B004OWULO0/ref=cm_sw_r_cp_apa_i_oswEDbHWKX703

Edited September 11, 2019 by blackrose

[blackrose]

39 minutes ago, ditchcrawler said:

I have a 2 foot stainless extension that fits in the top of my chimney for the odd occasions I have the back cabin stove alight. I had it made, it just slips about 2" into the top of the existing chimney 

 

The OP's chimney is already 2' long. If he adds another 2' it might make a difference I suppose but anything longer than 4' is starting to get a bit ridiculous on a boat. 

 

Try cleaning it all out first and if that doesn't help then perhaps look at buying a section of vitreous enamel flue pipe of the correct diameter. That's what I have as a chimney. Mine is nearly 15 years old so it does last. Lots of suppliers online. If you can find a 1.5m length then just use that instead of your current chimney. 

Edited September 11, 2019 by blackrose

[nbfiresprite]

I use two 1m stainless steel flues cramped together, Which in turn are cramped to the collar with a pipe cramp, we do get strong winds here in the Fens, 120mm flue will give a tight fit to a 4' 3/4" collar.

[Phil111]

Thanks for your replies. Most appreciated.

[Ray T]

Do it the age old and tested way.

 

Edited September 12, 2019 by Ray T