If my stove’s safe, why’s there soot in my chimney?

Wood stoves should certainly be safe if they are installed by a proper HETAS-approved installer or similar professional chimney technician. If not, you could be in trouble. A professional installer will ensure the chimney is swept properly and there are no issues in the flue or flue liner (replacing if needed) and also ensure that the measurements of the stove, chimney and nearby room all complement each other. He or she will guide you in the correct choice of stove and then install it into the fireplace area. If you don’t have a chimney, a twin-walled system can be set-up for you.

So, let’s say the stove is installed and you’ve been enjoying indoor fires for a while. Why can there still be an issue with soot in the chimney? If you don’t like reading technical stuff… time to brush out of this blog and read another article on the James the Sweep website instead.

For those who like tech – stoves have 75 per cent more oomph than open fires (oomph isn’t a technical word but it conveys a better sense of power, compared to boring old ‘more efficient’). That means the nearby room receives more fuel heat and gas in the flue tends to be colder. This results in tar condensation. Generally, the atmospheric temperature is 50C for flue gas condensates (the tar liquid created by condensation) as a result of burning coal or wood. This all means that soot (tar, acid and other yucky stuff, to use another technical term) will be present in the chimney. Wood also has less oomph when it comes to burn rate, compared to coal, so you’d be likely to see an increase in condensates as a result.

Tars and acids will eat into your chimney structure and cause damage. Any cracks caused also carry the risk of leaking gas created by the fire, such as lethal carbon monoxide, into your home. Soot of course, blocking the flue, also means that gas cannot escape safely to the outside atmosphere – it will roll back down your chimney and into the room. It can kill you and your loved ones.

This all sounds dramatic and you may think, ‘Well, if it’s that risky, why bother with a stove or even an indoor fire?’ That’s understandable but the good news is that you don’t need to worry at all IF – and this really is an important ‘IF’ – you ask for advice from a chimney sweep, preferably a member of the Guild of Master Sweeps. A professional sweep will not only sweep the chimney to clear soot and other condensates. He or she will also keep a regular check on the set-up (ask for advice on how often it all needs checking) to ensure that it is safe to use. If there has been any damage, sometimes getting a flue relined (after remedial works to the chimney) or a new flue liner, a twin wall insulated flue pipe to keep the flue gas warmer, for example, would be appropriate.

The key message here is this: if you’re concerned about tar or acid deposits in your chimney, as a result of the stove, don’t worry. It can be remedied but you MUST contact your local chimney technician, ASAP. Make sure any chimney sweep is a member of the Guild of Master Sweeps. And if it’s an installer, check that he or she is registered with HETAS.

If you live in Kent or East Sussex  – just get in touch with James the Sweep. James oversees chimneys for customers in Tunbridge Wells, Southborough, Sevenoaks, Tonbridge, Crowborough, Hadlow, Hildenborough, Paddock Wood, Pembury and Maidstone.