Guide to Domestic Boiler Regulations

The government updated the Building Regulations on 15th June 2022. These changes directly impacted boiler installations and efficiency in the government’s drive to reduce carbon dioxide emissions by 30%.

This guide will introduce you to some of the new and existing boiler regulations.

New Boilers

Since 2005, regulations have dictated that all boilers must be condensing boilers with an ERP rating of 92%. The change was to help households to become more energy-efficient while benefiting from the safety associated with condensing boilers.

The new building regulations only apply to those who decide to change their existing central heating system or boiler or if they plan to switch to another heating source, such as an air-source heat pump.

Replacing boilers

Every new boiler installation must meet the building regulations to ensure safe installation and energy efficiency. As a result, it’s essential only to use an experienced boiler installer. To be confident you are using an appropriate installer, check their credentials. The requirements for a boiler installer are as follows:

  • Gas Boilers – should be installed by a professional boiler engineer who is Gas Safe registered.
  • Oil-fired boiler – the installer should be registered within the bodies in the Competent Person Scheme.
  • Solid fuel-fired boiler – the installer should be registered within the bodies in the Competent Person Scheme.

Boiler efficiency

All new boilers must be ‘A-rated’. The ‘A’ rating means that the boiler is 92% efficient. However, it is essential to note that despite the efficiency rating, you must have an effective installation to gain the maximum benefit of your ‘A-rated’ boiler.

As of 15th June 2022, central heating system radiators must run at no higher than 55°C. 

What is boiler efficiency?

Boiler efficiency refers to the percentage of the energy a boiler uses that is converted into useful heat. A high-efficiency boiler can convert a large proportion of its energy into heat. In contrast, a low-efficiency boiler converts a smaller proportion of the energy it uses into heat.

Boiler efficiency relates to how energy efficient a boiler is. The result is a percentage – 0% being inefficient and 100% being maximum efficiency.

For example, if a modern boiler has 93% efficiency, then 93% of the energy used by the boiler heats the home. 7% of the energy is lost in functioning the boiler itself.

Boiler Flue Regulations

The boiler flue regulations dictate how boiler flues must be installed safely. Waste gases from your boiler can be harmful, so installing boiler flues in the correct location is essential.

What is a boiler flue?

A boiler flue is a pipe or duct used to vent combustion products from a gas or oil-fired boiler to the outside of a building. The flue is typically made of metal or plastic and installed in a vertical or horizontal position. The position will depend on the type of boiler and the layout of the building.

The main function of a boiler flue is to provide a safe and efficient way for harmful gasses to be expelled from the boiler and the building. This is important because the products of combustion, which include carbon monoxide, water vapour, and other gases, can be harmful if they build up inside your home. In addition, the flue helps prevent backdrafting, which is when the combustion products are drawn back into the building rather than being expelled through the flue.

Boiler flues are typically located near the top of the boiler and are connected to the chimney or a separate flue pipe. It is important to ensure that the flue is installed correctly and maintained to ensure the safe operation of the boiler.

What are the Boiler Flue Regulations?

It is vital to install a boiler flue in the correct location to protect you and the people around you. In addition, your engineer must ensure that the site doesn’t put others at risk. 

There must be a distance of at least 600mm between the boundary line and the end of the flue. In addition, it is essential to avoid installing boiler flues close to footpaths and walkways.

The regulations state that the flue must be a minimum of:

  • 300mm away from any window that can open or air vents.
  • 1,200mm distance away from a door.

Your boiler size will dictate the distance your flue should be installed from openings. The regulations are a minimum requirement.

Boiler flues must be installed:

  • 25mm below any guttering, drain pipes or soil pipes.
  • 300mm above ground, roof or balcony levels.

Distances from neighbouring properties

  • A minimum distance of 600mm should be allowed, ensuring that a boiler flue is sufficiently away from neighbouring buildings or fences.
  • Boiler flues must be installed at least 2.1m off ground level if it faces a public space such as pavement.

Do I need planning permission for my new boiler?

Planning permission isn’t usually needed when installing a new boiler if all the work is strictly internal. However, if you live in a listed building, you should always check with your local planning authority.

If the boiler installation includes a flue outside your building, it must be under the following conditions:

  • Flues cannot exceed the highest part of the roof by one metre or more.
  • If the property is listed, you must check with your local planning authority before beginning any work.
  • In world heritage sites, conservation areas and any other restricted area, the flue should not be fitted on the principal or side elevation if it faces a highway.
boiler engineer

Where can my boiler be installed in my home?

Kitchens and utility rooms

Your kitchen or utility room is a popular home for a boiler. This is because boilers are ideally positioned on an outside wall and close to drainage.

Can I install a boiler in my roof?

Many homes already have boilers located in their loft space. However, there are some key considerations when installing a boiler in your roof space. The boiler must be hung on a brick or timber wall to ensure sufficient weight support.

The loft must be boarded from the hatch to the boiler with a permanently fixed light. In addition, there must be a ladder and a grab rail around the hatch.


Boilers can be installed into garages if fitted with a frost stat. The frost stat will prevent the pipes from freezing during the cold winter months. In addition, pipework should be coated in foil pipe insulation and positioned high enough to prevent the boiler from being disturbed.

Can I install a boiler in a Bedroom?

According to the Health and Safety Executive, a boiler can be installed in a bedroom as long as it is room sealed. This means that the boiler is completely enclosed, and there is no way for air to escape from the room into the boiler. This is important because boilers require oxygen to burn fuel and produce heat, and if there is not enough oxygen, carbon monoxide can be produced, which is a toxic gas that can be lethal.

The room-sealed boiler must also be installed according to the manufacturer’s instructions and must be regularly maintained and serviced by a Gas Safe registered engineer. It’s also important to ensure that the room has adequate ventilation to prevent the buildup of carbon monoxide.


Other Factors to Consider

While it may be legal to install a boiler in a bedroom, there are other factors to consider before making a decision. One consideration is noise. Boilers can be noisy when they are running, and if your bedroom is located close to the boiler, you may be disturbed by the noise. Additionally, boilers can produce heat, which may be uncomfortable in a small, enclosed space like a bedroom.

Another factor to consider is space. If your bedroom is small, you may not have enough space to accommodate a boiler and all of its associated equipment. You may need to consider alternative placement options, such as in a utility room or garage.

Finding a reputable boiler installer

Finding a reliable boiler engineer is essential to household boiler installation. As mentioned earlier, if you are installing a gas boiler, you will need a Gas Safe registered engineer. 

Good boiler installation ensures your boiler runs efficiently, reducing costs on your energy and increasing the lifespan of your central heating systems.

PHS Trades Team provide first-class boiler services to homes and businesses across London and the Southeast. We have over 20 years of experience installing and maintaining boiler systems while providing personable customer care. 

About the author

Trades Team are experts in Heating, Plumbing and Gas Services. We have 15 years of experience providing expert Boiler Repair and Boiler Servicing to homes and businesses across the Southeast. Learn more about Trades Team.

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