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Boiler Buying Guide

Boiler Buying Guide

Last Updated: 12th January 2022

Simple steps to take for a hassle free boiler installation

It may not be exciting but a boiler is one of the most important purchases you can make. Know what to expect and be prepared with our boiler buying guide.

Types of Boiler

With a few exceptions, all new and replacement boilers must be high efficiency condensing boilers that can reduce CO2 emissions by up to 25%* and could save you up to £365* per year on your heating bills. It makes sense to embrace this new technology and accept that the slightly higher initial purchase cost will re-couped through lower heating bills.

The next stage is to determine what type of condensing boiler will best suit your lifestyle and home. Regular (also known as conventional or traditional boilers), System or Combi?

In most cases this will be determined for you, if you live in a flat you’ll most probably need a combi boiler, if you have a large family home with no space restrictions then a regular boiler or system boiler will be best suited. Either way this is a job for an expert.

Boiler Manufacturers

When it comes to choosing a brand of boiler for your home there’s a lot to think about. From prices to efficiency ratings, we’ve summed up everything you need to know about some of the main boiler manufacturers on the UK market.

Alpha Learn more about Alpha Boiler efficiency ratings
Ariston Learn more about Ariston Boiler efficiency ratings
ATAG Heating Learn more about ATAG Heating Boiler efficiency ratings
Baxi Learn more about Baxi Boiler efficiency ratings
Biasi Learn more about Biasi Boiler efficiency ratings
Ferroli Learn more about Ferroli Boiler efficiency ratings
Firebird Learn more about Firebird Boiler efficiency ratings
Glow-worm Learn more about Glow-worm Boiler efficiency ratings
Grant Learn more about Grant Boiler efficiency ratings
Ideal Learn more about Ideal Boiler efficiency ratings
Intergas Learn more about Intergas Boiler efficiency ratings
Johnson & Starley Learn more about Johnson & Starley Boiler efficiency ratings
Keston Learn more about Keston Boiler efficiency ratings
Main Learn more about Main Boiler efficiency ratings
Mistral Learn more about Mistral Boiler efficiency ratings
Potterton Learn more about Potterton Boiler efficiency ratings
Ravenheat Learn more about Ravenheat Boiler efficiency ratings
Vaillant Learn more about Vaillant Boiler efficiency ratings
Viessmann Learn more about Viessmann Boiler efficiency ratings
Vokèra Learn more about Vokèra Boiler efficiency ratings
Warmflow Learn more about Warmflow Boiler efficiency ratings
Worcester Bosch Learn more about Worcester Bosch Boiler efficiency ratings
Zanussi Learn more about Zanussi Boiler efficiency ratings

Get 3 Quotes

We recommend you get 3 quotes from local and national installers. This will not only give you a good feel for the price you should be paying but will also enable you to assess their professionalism and knowledge against each other. Use boiler quotation services such as that offered by Boiler Guide to contact local heating engineers on your behalf.

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Find professional heating engineers in your local area

Bear in mind nationwide firms may be a little more expensive but often provide comprehensive after sales service and support packages.

Be Prepared

Before the engineer arrives to inspect your home be prepared. The engineer should ask you some important questions about your lifestyle and current system. This will enable correct specification of the boiler and central heating system. For more information about the type of system you may have in your home, check out our guide to central heating systems.

Have a think about:

  • Where the new boiler will be sited. New condensing boilers produce a plume of steam due to the lower temperature of the exhaust gas from the flue compared to older type boilers. This plume can be a nuisance for you and your neighbours so it’s worth considering the implications of siting the flue in the same location. The engineer will be able to help with this but bear in mind it may be an issue.
  • Your living habits. For example, is there potential for more than one shower to be used at any one time and how well your current boiler copes with demand.
  • Future plans. Do you have any plans to extend your house or convert the loft? regular boilers require loft space for feed and expansion tanks, system and combi boilers don’t.
  • Your budget. Know your budget, don’t be persuaded to spend more than you are comfortable with. It may be worth checking out any finance deals on offer.


Consider Solar

Modern solar technology may not be as expensive an option as you may think. Most boiler manufacturers also make solar systems that work seamlessly with their own boiler and controls.

Up to 1/3 of your hot water can be gained through solar thermal and combining this with a new boiler installation can be far cheaper than adding it at a later date, it will also add a great deal of value to your property. Government grants are available and solar systems attract just 5% VAT so it’s well worth discussing this with your engineer.

Other Energy Efficiency Options

It’s important to assess the energy efficiency of your home alongside the boiler installation. Supplementing loft insulation or installing cavity wall insulation can be a relatively low cost way to further reduce heating bills and ensure your boiler is working to its maximum efficiency.

Questions to Ask

Don’t be afraid to ask some questions, the engineer will be used to ones below being asked regularly and should be able to give straightforward, honest answers. If he can’t, ask why?

  • Ensure they are Gas Safe (for gas) or OFTEC (for oil) registered.
  • Ask them to provide local referrals.
  • What else is included? After sales service? (see below)
  • Ask for a full written quote itemising all work and parts.
  • What make and efficiency of boiler? Ensure this is specified within the quote.

After Sales Service

It’s essential to establish the after sales service/support the installer is offering. Some installers may be very competent at specifying and installing systems but are they able to repair them? Surprisingly not all have the knowledge to fault find and diagnose problems on the new breed of hi-tech condensing boilers.

Be sure to check their credentials preferably going with a firm that is qualified by the manufacturer to install that make of boiler.

Most of the nationwide installers offer ongoing boiler service and boiler insurance plans. British Gas for example include a years free British Gas HomeCare with all their boiler and central heating installations, this package not only covers the boiler and controls but the whole central heating system, even if it wasn’t installed by British Gas. Well worth considering.

Get FREE Boiler Quotes Now

Find professional heating engineers in your local area

  • Know your budget
  • Think of future needs
  • Ask questions
  • After sales service?
  • Get 3 quotes
  • Cheapest is not always best

Selecting the Supplier

Once you have all the quotes in go through them carefully, ensuring you’re comparing apples for apples. Check that they are offering comparable makes and models of boiler. Ensure the outputs and efficiencies of all boilers are similar, if not, question why.

Remember, it’s not all about price but the full package on offer, including the ongoing maintenance.


Data Source: Energy Saving Trust, Heating Your Home: Boilers (2022) *Based on replacing an old gas boiler with a condensing A-rated boiler with thermostatic radiator valves, programmer and room thermostat in a detached home. Figures are based on fuel prices as of November 2021.

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