Chimney Flue Design

Can I Take A Bend Straight Of The Top of the Stove or Appliance?

No, always ensure that the first section of  flue vent rises vertically from the appliance a distance not less that 600mm.

Can I Take The Flue Horizontally?

No, horizontal runs must not be used as they cause resistance to the movement of the flue gas or smoke.

Can I Use An Angle Greater Than 45deg From The Vertical?

No, this should be avoided as it causes resistance to the movement of flue gases or smoke.

How Far Can I Offset The Flue System Without Causing A Resistance To The Flue Gas Or Smoke?

The length between bends must not exceed 20% of the total chimney length.

If I Am Using Stove Pipe Internally In The Room Where The Appliance Is And I Need To Change To An Insulated Product, Where Do I Make the Change?

The insulated chimney must project at least 150mm down from the ceiling before the connection to the stove pipe is made.

How Far Through The Roof Does The Chimney Need To Penetrate Before I Can Put On The Terminal?

Building regulations dictate that any chimney serving a solid fuel or oil fired appliance must be 2.3 metres horizontally clear of the roof line. (In the case of gas 1.5 metres).

The Chimney Is Very Short

Most stoves, room heaters and open fires require a minimum flue height from the top of the appliance or opening of between 4 and 4.5 metres. If your chimney is shorter than this then possible solutions are the fitting of an Aspirotor Spinning Cowl to improve the updraught or alternatively an electric chimney fan maybe your only solution.


Smoke Blowing Back from Chimney into the Room.

Does the problem only occur on windy days? If yes, fit a cowl to resolve the problem. Try a Colt top or Mini Eurocowl.

The Chimney Is Incorrectly Sized For The Fireplace Opening.

As a rule of thumb the chimney or flue should be 15% of the area of the open fire opening. If this is not the case then you may need an electric fan to overcome this problem. Other possible solutions are to reduce the fireplace opening or install a canopy to reduce the opening. Need any further help you can email us info@chimneyproductsdirect.co.uk.

I Have Too Much Draught And I Constantly Have To Stoke The Fire With Wood Or Coal

Try the Mini Eurocowl which provides even air flow over the top of the chimney to reduce updraught in the appliance or open fire.

I Have Damp Or Soot Marks On The Wall Where My Disused Chimney Is

Provide permanent ventilation to your fire with an air vent in the wall where the fireplace was and cap the top of the chimney with a rain cap.

We Have Lined The Flue With A Flexible Flue Liner And Now The Fire Does Not Draw As Well.

Install the Aspirotor, a spinning cowl, to increase the updraught or alternatively you may require an electric chimney fan.

The Gas Pilot Light Of My Gas Flame Effect Fire Keeps Blowing Out On Windy Days

Try the Colt Top cowl or Mini Eurocowl.

I Am Fitting A Live Flame Effect Fire (LFE) Or Decorative Flame Effect Fire (DFE) What Type Of Cowl Should I Use?

We would recommend the Colt top 2.

I Have Insufficient Draught In My Chimney And The Flue Gas Keeps Spilling Around The Fire Opening.

Use a Spinning cowl, Aspirotor Cowl, to increase the updraught.

What Size Of Chimney Pots Do Your Cowls Fit?

They fit a standard pot 200mm - 250mm ( 8" - 10" ) in diameter. (But if your pot is larger the Large UFO will fit 300mm - 350mm (12" - 14")).

What Size Of Flue Liner Do I Need For My Open Fire?

An open fire burning wood or coal needs to be a minimum of 200mm (8") in dia but if this is not possible you could consider the 180mm (7") and finish with an Aspirotor cowl to help increase the updraught.

Is There A Cowl Suitable For Coastal Areas?

The steel Mini Eurocowl should be considered as it is made from 316 grade stainless steel which copes better with sea water atmosphere. Remember to select the steel option.

Do You Stock Any Cowls For A Larger Round Chimney Pot, Dia 300mm - 350mm?

Yes but only one - the Large UFO.

Is There A Cowl To Reduce Wind Noise?

If the chimney is not in use, we would suggest you try a chimney balloon and you buy, from your local builders merchant, a clay cowl called a flue vent as this will definitely help your noise problem from the chimney.

If the chimney is in use then you could try an appropriate cowl for your fuel type. See our Chimney Cowls and use our useful "need help choosing a cowl" tool. Unfortunately there are no proprietary cowls made to deal with wind noise specifically, but speaking to neighbours who may have found a solution to the chimney noise problem with a specific cowl may be your best option.

Is There A Cowl To Reduce Wind Noise When I Have A Gas Appliance?

There are no proprietary cowls designed to tackle wind noise. The clay cowls are better at preventing wind noise but you would need to take advice from a gas engineer about an appropriate model and these are not sold online you would need to source them locally.

What Chimney Cowl Or Cap Do I Need?

All depends on what type of fuel you are burning, what you are fitting the cowl to and why you need one. Is it to stop downdraught or increase updraught or simply to prevent rain and bird entry? Our friendly Staff can help you - phone us on 0131 336 3589 or go to the Cowls page and answer the 3 simple questions for a list of Chimney Cowl options

Chimney Cowls are in stock ready for quick dispatch throughout the UK.  We supply both Trade and Retail customers.

Get in touch

For more information please get in touch:

Tel: 0131 336 3589

Email: sales@gchristies.co.uk