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Home and community

Gas boiler regulations

If you are planning to install or replace an existing gas boiler you should choose a condensing boiler. This is a requirement of Part L1 of the Building Regulations that relate to the conservation of fuel and power.

Why install a condensing boiler?

Gas-fired boilers installed after 1 April 2005, and oil-fired boilers installed after 1 April 2007, must be condensing boilers, whether they are replacements or new installations.

Condensing boilers are more efficient than ordinary boilers as they:

  • produce less carbon dioxide while still meeting heating needs
  • reduce the amount of heat that is lost through the flue, compared with ordinary boilers
  • convert 86 per cent or more of the fuel they use into useful heat (older types of ordinary boilers may convert as little as 60 per cent of fuel to useful heat)

The new standards apply only if you decide to change your existing hot-water central-heating boiler or if you decide to change to one of these boilers from another form of heating system.

Climate change has been caused by increasing amounts of carbon dioxide being released into the atmosphere. Around 16 per cent of the carbon dioxide that the UK produces comes from the gas and oil boilers that we use to heat our homes.

How will a condensing boiler benefit you?

They may be more expensive to install, but you will:

  • save money on your heating bills
  • help to tackle climate change

Do you have to have a condensing boiler?

No. You should have a condensing boiler fitted if it is reasonable to do so, but the law recognises that non-condensing boilers are acceptable if it would be too difficult to install a condensing boiler in your home. Your installer will tell you whether your circumstances are too difficult.

Who should install your boiler?

For gas-fired boilers, the installers you employ must be on the Gas Safe Register as a safety and legal requirement, and they should also be capable of installing condensing boilers.

For oil-fired boilers, you can employ an Oil Firing Technical Association (OFTEC) registered installer or some other reputable installer who is capable of installing condensing boilers. OFTEC members are approved to certify that their work meets building regulations. If you employ an installer who is not registered with OFTEC, you will need to tell your local authority's building control department before the installation work starts.

In all cases, check that your installer has recent qualifications in energy efficiency. Gas Safe Register or OFTEC can confirm this. If the installation is for an oil-fired boiler, an alternative would be to ask your installer if they hold a Certificate in Energy Efficiency for Domestic Heating or an equivalent qualification.

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