How do I buy a high efficiency condensing boiler?

Before looking to buy a new condensing boiler and heating controls you should ensure that your home is fully insulated

Once your home is fully insulated your first step when buying a new boiler should be to get at least three quotes. One of the best ways to find a reliable installer is to ask around - and get a personal recommendation from a trusted friend or relative.

To make sure you're complying with Gas Safety Regulations, you should always use a Gas Safe registered engineer. In Great Britain, all work on gas applicances must be carried out by an engineer on the Gas Safe register which replaced the CORGI* gas register in Great Britain on 1st April 2009.

We strongly recommend that any boiler or heating systems are fitted by an installer who is registered with a Competent Person Scheme. Competent Person Schemes were introduced by the government to allow individuals and businesses to self-certify their work as compliant with UK Building Regulations. Most installation or upgrade work done on your heating system is subject to Building Regulations. These regulations vary depending on where you are in the UK, but generally all work must be notified to your local authority.

Competent Person Scheme installers can self-certify their work as compliant with Building Regulations. They can also notify the
local authority on your behalf and issue you with a certificate on completion which can be used as proof of compliance for the Home
Information Pack (HIP). It will also show up on a solicitor's Local Authority search when you sell your home.

If you don't use an installer registered with a Competent Person Scheme then you will have to submit a building notice or full plans application and pay a fee to have Building Control come and inspect the work you have carried out.

To find an installer registered with a Competent Person Scheme, visit competentperson.co.uk and enter your postcode or the name of the installer in the relevant search box.

Please also see below, a list of Competent Person Scheme operators:

*CORGI will continue to operate in Northern Ireland, Jersey and Guernsey.

Other checks you can make about installers include asking:

Does the installer have a local office?
Has he/she been in business locally for several years?
Are customer references available that you can check?

Your local council may also be able to help with a list of qualified installers. Visit centralheating.co.uk to find out more.

Looking after your central heating system

When your new boiler is being installed or serviced, your installer should also need to clean and flush your central heating system, and add a chemical inhibitor which helps to reduce lime scaling and corrosion. This will remove any limescale or sludge in your heating
system, ensuring your heating continues to work as efficiently as possible.

There are three main treatments which can be used:

Flushing: This will either involve a `powerflush', or a mains pressure water flush (which will take longer).
Inhibitors: Chemical inhibitors can be added to the system which help prevent build up of lime scale and help prevent corrosion.
Water softeners: If a combination boiler is installed in a hard water area, water softeners can be added to the system.

Powerflushing is the most thorough and effective way to cleanse existing systems - and hot flushing is more effective than cold flushing. But the method your installer uses depends on your make of boiler, as does the type of cleanser. Your installer should always check and stick to the manufacturer's instructions.

Any maintenance work on your boiler in years to come should also be carried out by an Gas Safe or CORGI installer (CORGI will continue to operate in Northern Ireland, Jersey and Guernsey). Your installer will also be able to tell you when you need to get your boiler serviced.

Your boiler should usually be serviced once a year by an installer. When your boiler is serviced, you should check that the system is clean; this will ensure your heating system continues to work as efficiently as possible.

A system may benefit from cleaning:

If a system is `cold-spotting' - where the radiators do not provide uniform heat and feel cold to the touch in patches.
When the system pump can be heard `labouring' - because the system is pumping round not just water, but also the build up of sludge or lime scale.

Please remember to keep any boiler-related certificates in a safe place. You'll need them when you sell your home.

If you're looking for an installer, your local advice centre will be happy to put you in touch with registered professionals in your area. Call 0800 512 012 for free, independent advice.