Combi Boiler Prices and Cost Guide

Do you need a new boiler? Then installing a combi boiler could be a good option - they're small, compact and energy efficient. Whether you need a gas, electric or oil-fired combi boiler, find out how much it’ll cost you to buy, professionally install and service one here.

How much does a Combi Boiler cost?

Average cost in UK: £2300

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The average cost for a Combi Boiler is £2300. You are likely to spend between £600 and £4000 total.
Exact price may vary depending on your area and project details.

Next Step: Find out exactly how much your project will cost.

How much does a Combi Boiler cost?

Average cost in UK: £2300

Get local prices







The average cost for a Combi Boiler is £2300. You are likely to spend between £600 and £4000 total. Exact price may vary depending on your area and project details.

What is a combi boiler?

You can choose from two types of boiler:

  1. Regular system boiler: has a storage cylinder for hot water and is designed for a home that uses a lot of hot water

  2. Combi boiler: do not have a cylinder for water storage but heat water on demand and are overall more efficient

How much does a new combi boiler cost?

Combi boiler prices UK depends on the size and output of the boiler and the fuel it burns. According to the EST the average price is £2300 including the installation.

Gas combi boiler price comparison:

  • Alpha CDC combi boiler is £504.32 before VAT from Discounted Heating online (EST recommended at 90% efficiency)

  • Baxi combi boiler is between £650 and £1105 including VAT from the manufacturer

  • Vaillant combi boiler is between £725 and £1130 including VAT from the manufacturer

  • Worcester Bosch combi boiler is between £681 and £1400 including VAT from the manufacturer

Get more information on new combi boiler prices.


Oil combi boiler prices

Oil combi boiler prices:

  • Thermasaver from Discounted Heating online is £1434 before VAT

  • Greenstar Camray from Discounted Heating online is £1038 before VAT

  • Warmflow are between £1700 and £1950

Get more information on oil combi boiler prices here.


Cheapest combi boiler prices

You may be able to find a cheaper combi boiler if you buy a second hand or reconditioned model. For example:

  • Reconditioned boiler prices  are between £650 and £1000

  • Ex-showroom boilers are between £500 and £800

Get more information on the cheapest combi boiler prices.


Whether you are looking to replace an old electric combi boiler or install a brand new boiler, a combination or combi boiler is what you will need to heat your home efficiently. With our combi boiler price guide we will explain the costs of new boilers that include installation, fitting and servicing costs. We will also show you how to find the best prices and best type of boiler and the necessary regulations and grants.


Combination boiler installation costs

Combi boiler prices and installation will depend on the size of boiler you purchase as well as the location. You can also purchase a gas combi boiler to replace your old boiler if you prefer. If you are just replacing a boiler installation will be less than relocating a new combi boiler.

  • Gas Safe engineer when installing a gas combi boiler. It’s a legal requirement in the UK that anyone who installs, services or repairs gas appliances must be registered with Gas Safe
  • A member of the Oil Firing Technical Association (OFTEC) for an oil burning boiler
  • qualified electrician to install an electric combi boiler to BS 7671: 2008 Requirements for Electrical Installation

The EST suggests you get three quotes for comparison and ask for references. If the installer is not one of the above you will have to pay more for a building inspector to inspect the installation.

Installation of combi boilers varies in price but you can expect to pay:

  • Around £600 to replace an existing boiler with a new one

  • Between £1500 and £1800 to install a new boiler

Get more information on combi boiler installation prices.


Fitting costs

The cost of fitting your combi boiler will vary depending on who you hire to do the work. The following companies provide combi boiler fitting:

  • British Gas charge between £800 and £1,550
  • EDF Energy will fit a combi boiler for £800 to £1400

Get more information about combi boiler fitting costs.


Vaillant combi boiler prices

Vaillant is one of the most well known boiler manufacturers and have been in operation for more than 135 years. This makes the Vaillant combi boiler a popular option; prices will vary depending on where you buy yours from and how big it is:

  • A Vaillant Eco-Tec Pro 24 combi boiler costs £610
  • A Vaillant Eco-Tec Plus 31 costs  £1,000

Get more information about Vaillant combi boiler prices.


Combi boiler servicing costs

It’s essential that you get your combi boiler serviced at least once a year to ensure that it’s operating safely and efficiently. A service will:

  • Detect any serious faults – saving you  money on future repairs and expensive emergency call-outs
  • Save your life – by detecting lethal Carbon Monoxide leaks and other dangerous defects
  • Reduce your fuel bills – by making sure your boiler runs at its most efficient
  • Stop you breaking the law – landlords are legally obliged to carry out annual boiler serviced in rental properties

The EST say that a boiler service will cost between £50 and £75 – find out more about servicing your boiler.


Should I install a combi boiler?

Combi boilers are suitable for:

  • Combi boilers are suitable to be installed in small buildings that do not have the need for large amounts of hot water such as a one bathroom house or flat

  • Small properties without large storage areas as a boiler will fit into a kitchen or laundry cupboard



When you are installing a replacement or new combi boiler certain regulations need to be met. The installer can make sure all of these comply:

Condensing models – as of the 1st of April 2005, part L of UK building regulations state that all new boilers must be condensing models. This means that they recover more heat from waste gases than non-condensing models and are therefore up to 12% more efficient, says the EST. There are some very rare exceptions to this rule, for instance if the boiler cannot be positioned safely, even when using an extended flue. In these instances a qualified engineer will provide you with a certificate to prove that you need to install a non-condensing boiler instead

Planning permission – you won’t need planning permission to install your new combi boiler if all the work involved is internal. However, if your new boiler installation involves inserting a flue outside your home, or if you live in a listed building, you should consult your local building authority for advice before installing your combi boiler

Building regulations – from October 2010, building regulations stipulate that all new boilers should be A-rated or at least 88% efficient according to the Seasonal Efficiency of Domestic Boilers in the UK (SEDBUK) scale. SEDBUK has two rating systems, the 2005 one uses an A-G ranking (A being the most efficient rating) and the 2009 scale works in percentages. The EST say that a new A-rated condensing boiler can save you up to £300 and 1,220kg of C02 per year, depending on what type of boiler you’re replacing

Heating controls – Part L of building regulations requires you to fit proper heating control systems when installing a new boiler. There are different types of controls to choose from but you basically need a programmable room thermostat to control the timing and temperature of your heating. Good controls can save £55 and 280kg of CO2 per year, reports the EST


Combi boiler grants

You may be eligible for a grant towards the cost of installing or maintaining your combi boiler from one of the following outlets:

The Warm Front Scheme – this is a government scheme for residents in England which is set to be phased out over the next few years. If you own your own home or privately rent, you could be eligible for a grant of up to £3,500 towards heating and insulating your home. A similar scheme called the Warm Homes Scheme runs for those living in Northern Ireland and in Wales you can get help from the Fuel Poverty Scheme.

The Scottish boiler scrappage scheme – the Scottish government have extended their boiler scrappage scheme whereby they offer £400 per household towards the cost of replacing an old (typically one over 10 years old) with a new Energy Saving Recommended boiler. Terms and conditions apply; consult the EST to find out if you’re eligible. Elderly Scottish residents and those on benefits may also be able to get a grant through a local government Energy Assistance Package.

Energy supplier grants – Carbon Emission Reduction Targets (CERT) require energy companies to help their customers make energy saving home improvements. This may include providing discounts for new boiler installation. You’re eligible for grants from any energy company, not just the one who supplies energy to your home.

Local government grants – your local government or home improvement agency (HIA) may also provide grants towards the cost of heating and insulating your home – ask yours for more details.

Written by WiseTradesmen


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