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What are Boiler Flue Regulations?

To keep everyone in your home, as well as the neighbours, safe from potentially harmful gases expelled by your boiler, boiler flue regulations have been introduced. These regulations don’t apply to installations that took place before the regulations came into effect, but if you’re having a new boiler installed, then following the steps in this guide will leave you safe in the knowledge that your boiler flue is in the safest place possible.

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Recognising a Boiler Flue

Before you can make sure that it’s in a safe place, you need to know exactly what a boiler flue is. Boiler flues are a pipe or duct, often found protruding from an outside wall or roof that are attached to gas boilers. They give the waste gases produced during the heating process a safe escape route into the atmosphere rather than staying in the home.

Why are Boiler Flue Regulations Important?

When operating, boilers produce some gases that could prove harmful if breathed in, such as carbon monoxide. These gases are then expelled through the boiler flue into the atmosphere, where they can’t cause harm to anyone.

Boiler Flue Regulations

The boiler flue regulations take into account several things, from the position of the flue to the direction that it can face. Find out how to ensure that your new gas boiler flue meets the regulations with the table below.

Regulation TopicWhat it Means
LocationBoiler flues are installed to send harmful gases generated by the boiler out into the atmosphere so it makes sense that they’re enough of a distance away from any doors and windows that they can’t re-enter the home. The regulations state that the flue must be between 30-60cm away from any parts of the home that open up, with the exact distance depending on the size of your boiler.
TemperatureThe gas being expelled by the flue is hot as it’s generated when the boiler is burning fuel so it’s important to keep it away from anything made out of plastic, such as guttering, as you won’t want it to melt.
Public AreasIt’s important to consider those passing by your home as well as those inside it when finding a position for the boiler flue. So, if your flue points in the direction of a public space then it will need to be above head height, which is at least 2.1 metres.
Vertical FluesThe above points only really apply for flues that exit the home horizontally through a wall but that doesn’t mean there aren’t any regulations if your boiler flue goes vertically out of the roof.

As they pass through the home, up to the roof, vertical flues are either boarded over or housed inside a cabinet. It’s stated in the regulations that this cover must have openable panels at several points along the way to make servicing much easier for the engineer.

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Will I Have to Move my Current Boiler?

If the flue from your current boiler doesn’t meet the regulations then there’s a chance that it might need moving or a new boiler installation might be required. Having said that, it’s worth checking with a qualified heating engineer as many of the regulations only apply to new boiler installations.

Planning to Move Your Current Boiler?

Whether you’re moving your current boiler from one room to another or just further down the same one, the position of the flue will need to be considered. A typical boiler move could cost around £300 – £800 but if the flue has to be moved or extended then there will be some additional costs.

Required WorkPossible Cost
New flue£70 – £120
Extension to current flue£40 per metre

Will I Need Planning Permission to Fit a New Boiler Flue?

With a boiler flue heading outside it can be easy to think that you’ll require planning permission to have a new one fitted but if it’s within the regulations then you shouldn’t need any permission. To know that your flue will be within the regulations, you will need a Gas Safe Registered engineer to carry out the work.

If you plan to fit the flue outside of the regulations, which we’re not recommending, you will most likely require planning permission.

Who can Install a Boiler Flue?

There’s only one surefire way to ensure that your boiler flue meets the regulations and that’s with a Gas Safe Registered engineer. You can get free quotes from up to 3 qualified engineers in your area by filling in one a simple online form on Boiler Guide today.

Remember that if your current boiler flue doesn’t meet the regulations then you don’t have to immediately install a new one because they only apply to new installations. However, if your boiler was installed between 10-15 years ago then it would be a good idea to consider a new boiler installation as it will be more efficient, help you save money on your energy bills and have a flue in a safe location too.

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