LONDON’S AIR QUALITY – Using Wood-burning Stoves Correctly


Wood-burning stoves have been the subject of various hostile reports in the past few years, more recently the London Mayor Sadiq Khan wrote to Michael Gove, the environment secretary. The mayor has asked to amend the Clean Air Act to give him the powers to create zones where the burning of solid fuels such as wood is restricted.

Researchers at King’s College London have found that wood-burning in the capital accounts for up to 31% of the city’s particulate pollution, up from 10% in the past. The tiny particles, known as PM2.5, are the most harmful type of air pollution and exacerbate lung and heart conditions.

People who use gas heaters may not realise that they can be lethal if they are faulty or not maintained properly as they can leak carbon monoxide. Because carbon monoxide can’t be seen and has no smell it can cause death or make people extremely unwell. Carbon monoxide can happen in any home that has gas connected so it’s critical to have appliances and pipes checked by a professional at least every two years.

Correct use can reduce the impact of wood-burning stoves by a whopping 80%!

There is a problem with air quality in  London which can cause health issues for all of us.  Wood burning stoves and open fires are responsible for a part of this problem but if we understand why, we can make a big difference.

Kieran Whelan from Fireplaces and Heating Direct in Luton, says: “Here in the UK, we have just been getting our energy labels for Gas fires and wood-burning and multi-fuel stoves, and whist the gas fires are all scoring Ds and C, the wood-burners are all scoring As and A+s! So, don’t think dirty old black boxes when thinking about wood-burners; these days they are state-of-the-art, efficient, and clean.

“Our regular maintenance top tip would be to always clean the glass before every burn. We use a bit of paper, and dip it into the ash to clean the glass; it works a treat!”

Collin Champagne, a 10 year Certified Master Hearth Professional and Content Writer at, adds: “Huge leaps in burn technology have been made in a relatively short amount of time. Wood stoves were previously nothing more than a steel or cast iron box used to contain the fire and absorb and then radiate heat to the room. Little concern was paid to particulate output, with the focus instead placed on maximum burn times. Choking down the air controls and dampers on these older stoves often resulted in slow burning smoky fires.

“Modern stoves can still achieve a long burn time, but newer catalytic and recirculating technology allows the particulate matter that would have been released to the atmosphere to be filtered or re-burned before leaving the firebox. It is because of this fact that a modern wood stove will always be the better bet, making reconditioning an older model a futile exercise. Both stoves and fireplaces are manufactured and listed to the specifications they are originally built under. Field modification is not allowed and should not be attempted. In other words, do not attempt to make an older wood stove meet high efficiency standards. Open wood burning fireplaces will always produce more smoke than sealed appliances, but that doesn’t mean they cannot be improved. Ensure that the fireplace meets the 10:1 rule. That is to say, 10 square inches of fireplace opening area to 1 square inch of flue area. With this ratio maintained and the chimney built to the 10/3/2 rule, the fireplace will perform to the best of its ability. It can be costly to rebuild an entire masonry fireplace, but relining the chimney to correct any sizing issues is cost effective and can yield cleaner burning fires.

“At the minimum, have the chimney system inspected on an annual basis if you use the fireplace or stove occasionally during the burn season. Regular users should consider bi-annual inspections due to the increased likelihood of creosote buildup. It is recommended for regular users to train themselves to look for dangerous levels of soot buildup, as well as any cracks or degradation to the brick or metal of the fireplace or stove. If firewood is bought in, pay careful attention when burning the first logs of a new batch, as any green wood that is mixed in can result in a spike in particulate output.”


All larger towns and cities have Smoke Control Areas, often called “Smokeless zones”. If you use a wood-burner or open fire in a Smoke Control Area it is important to know the rules.

In an open fire – You are only allowed to burn smokeless coals or anthracite.

You will be committing an offence if you burn wood logs, wood products or normal “house coal”. You are however still allowed to start the fire with small wood kindling etc. Not only is it an offence to burn unauthorised fuels, but you’ll be introducing a large amount of damaging pollution in to your local neighbourhood. If we ignore these rules, it’s bad news for air quality.

Any stove installed in a Smoke Control Area must legally be an “exempted appliance”, often referred to as Defra EXEMPT.

“A big problem here is a lack of enforcement of the Clean Air Act,” said Dennis Milligan of the Stove Industry Alliance. He said that burning unauthorised fuels on open fires, were the real problem contributing to London’s dirty air.

You can check if your property is in a Smoke Control Area by contacting environmental services at your local council. Many councils will have this information on their websites.

Our schools, homes, recreational areas and our workplaces are often within a Smoke Control Area. If you use a wood-burner or open fire in a Smoke Control Area, there are some important rules to keep us all safer.


London's air quality - using wood-burning stoves correctly

  • Exempted appliances are designed to burn the fuel more efficiently and so reduce potential air pollution. Even so, they do vary a lot from one make to another so it’s still very important to use them correctly.
  • If the temperature inside the stove is not high enough then the wood cannot burn efficiently. If the wood is not burning hot and efficiently then more of the damaging particles will pass up the chimney and out in-to the air we breathe.
  • Bring the stove to operating temperature quickly and try to keep it there.
  • Using dry wood is very important. It should contain 20% moisture or less. But, even if your wood is very dry, you will still create a real problem if the air controls to your stove are closed too much.
  • Never try to “slumber” your stove for long periods / overnight with the air controls closed off too much. Loading up the average stove to slumber for a long period can easily produce more than a kilo of tiny damaging particles which then pass out the top of your chimney and in to the air we all breathe.
  • Logs should not be too large – 5 inches wide ( 125mm) will give the best result. Using large logs to make the fire last longer will usually result in a lower burning temperature, more wasted fuel and more pollution.
  • Sweep your chimney regularly – A professional sweep can give lots of useful extra advice.
  • Don’t buy a stove which is too big (too powerful) for the room. You’ll get too hot and be likely to shut the air controls too much. The burning temperature will drop, fuel is wasted and pollution increased.
  • Use a thermometer, moisture meter and stove fan to help improve efficiency, save money and reduce pollution.
  • Don’t burn plastic waste or treated waste wood. It stinks and it’s toxic 


  • If you have an older or inefficient stove or one that’s too powerful, consider replacing it with a modern efficient model. You’ll instantly begin to save money and burn cleaner.The Ecodesign Ready scheme has been put into place to ensure new British wood burning stoves meet high environmental standards. The stoves of tomorrow are here now.
  • Ecodesign Ready stoves can reduce PM emissions by 90% compared to an open fire.
  • More efficient use of heat in living area.
  • Modern wood burning stoves are virtually carbon neutral.
  • Ecodesign Ready stoves are banded A+ at 80% efficient.
  • Stoves are not just a fashion fad, they are a serious form of home heating.
  • Ecodesign stoves are part of the solution to PM emissions.

Jane Wilson from Modern Housewives agrees “that there are numerous benefits to using a wood-burning oven, the most important ones being they’re energy efficien and the fact that you’re not dependant on standard electricity”


  • A regularly maintained appliance will ensure that it is always working safely and efficiently. A professional chimney sweep is trained in all aspects of solid fuel this is where the knowledge and experience can make all the difference.
  • A clean flue will ensure the gasses from combustion can travel quickly and unrestricted. A clogged flue will cause the gasses to slow down and cool, creating more particulates and soot.
  • We recommend inspecting your rope seals annually. A damaged seal can cause your stove to draw more fiercely and over-fire. A sweep will be able to replace this for you if necessary.
  • Visual inspection of the terminal – an incorrect terminal can cause large soot deposits.
  • Is the chimney the right size and height? Is the ventilation to the room sufficient?
  • Are there conflicting problems with other fires or extractors in the building?
  • Check fuel storage and moisture content
  • Sometimes a fire or wood-burner can be correctly installed but there are issues with poor function, smoke to the room, lack of heat, black glass etc, etc.

Check our blog regularly for more in-depth information relating to all aspects of solid fuel. If you would like to make an appointment or have any questions, please feel to contact us on either 02083517164 or

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