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Combi Boiler Prices UK: All Costs Explained + Saving Tips
- The average cost of a combi boiler for a 1-2 bedroom house is £2,225, for a 2-3 bedroom house it is £2,580, and for a 4+ bedroom house it is £2,405.
- The average annual running cost of a gas boiler is £940, an electric boiler is £4,155, and an oil boiler is £1,380.
- The servicing cost of boilers is around £70 - £300 per year.
Combi boiler costs in the UK can range from £1,600 - £6,000, including installation. Combi boilers are the most commonly installed boilers in the UK as they perform the dual function of providing heating and hot water. Additionally, they are widely preferred because of their space-saving design, as they do not require a hot water storage tank.
In this article, we will walk you through new boiler costs for gas, electric, and oil combi models. If you think a combi boiler is the right fit for your home, it is recommended that you get a professional for the installation process. Fortunately, you do not have to spend hours of your time calling and comparing different installers on your own.
With GreenMatch’s seamless service, you can get up to 3 free and non-obligatory quotes from our network of verified installers. All you need to do is fill out a 30-second form to get tailored quotes in 48 hours.
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- Combi Boiler Prices UK: All Costs Explained + Saving Tips
- Combi boiler costs in the UK (2025)
- Gas combi boiler costs
- Electric combi boiler costs
- Oil combi boiler costs
- How much does it cost to install a combi boiler
- Servicing costs for combi boilers
- Grants for combi boilers
- Find the best combi boiler prices near your area
- FAQ
Combi boiler costs in the UK (2025)
Combi boiler prices can be £600 - £4,000 (supply only), depending on the boiler output size, fuel type, and brand. In the table below, you can find more information about the average cost for different combi boilers based on output sizes.
| Household size | Boiler Size | Cost (supply only) | Average cost (excluding installation) |
|---|---|---|---|
| Small 1-2 bedroom | 18kW - 27kW | £550 - £3,900 | £2,225 |
| Medium 2-3 bedroom | 28kW - 34kW | £660 - £4,500 | £2,580 |
| Large 4+ bedrooms | 35kW - 43kW | £850 - £3,960 | £2,405 |
Costs are estimates based on our team’s market research. These prices include all fuel types (gas, oil & LPG). Contact an installer for quotes now!
For a small-sized house with 1-2 bedrooms, an 18kW-27kW size boiler is sufficient. Combi boilers of these sizes would provide a water flow rate of 9.6-12 l/min, which is enough for 1 bathroom and up to 10 radiators.
The domestic hot water flow rate refers to the volume of hot water a boiler can deliver to water outlets, measured in litres per minute (l/min). The mains water supply flow rate, boiler output and number of water outlets in the house affect the domestic water flow rate.
Similarly, for a 2-3 bedroom house, a 28kW-34kW combi boiler would suffice. This would ensure a water flow rate of 10 to 16 l/min, ideal for 2 bathrooms and 15 radiators. For a large house with 4+ bedrooms, a combi boiler of 35kW-43kW is recommended. With a water flow rate of 16-18 l/min, this would be suitable for 3 bathrooms and 20 radiators.
Gas combi boiler costs
Gas boilers cost around £600 - £3,300 in the UK. They have low running costs, with an energy efficiency of 90% to 94%, and last for 10-15 years.
| Supply cost | Installation cost | Total cost | Average cost | Average running cost (annual) |
|---|---|---|---|---|
| £600 - £3,300 | £1,000 - £2,000 | £1,600 - £5,300 | £3,450 | £940 |
Costs are estimates. Contact an installer for accurate quotes!
Gas combi boilers dominate boiler sales in the UK as gas is the most affordable fuel at 6.99 pence per kWh. This would bring the annual running costs around £620-£1,260. They typically come in output sizes of 18kW to 40kW.
There are a lot of options with gas combi boilers for different budgets. The premium brands such as Worcester Bosch £935 - £4,000, Viessmann £1,050 - £2,200, and Valliant £900 - £2,300 are on the higher end of the price spectrum. The more affordable brands include Biasi (£635 - £665), Baxi £660 - £1,500, and Alpha (£650 - £1,250) for cheap boilers.
Electric combi boiler costs
Electric combi boilers can cost around £980 – £3,000. They are not the most popular option in the UK as the running costs can be quite high compared to gas boilers. Electricity costs 27.03 pence per kWh and the monthly running costs can be anywhere from £192 to £500. The annual running costs could be between £2,305 and £6,000.
| Supply cost | Installation cost | Total cost | Average cost | Average running cost (annual) |
|---|---|---|---|---|
| £980 – £3,000 | £1,000 - £2,000 | £1,980 – £5,000 | £3,490 | £4155 |
Costs are estimates. Contact an installer for accurate quotes!
Electric boilers might not be suitable for larger homes with high heat and hot water needs due to their limited capacity (15kW maximum). However, electric boilers have no carbon emissions and are almost 100% energy efficient. There is no risk of a gas leak or the headache of fuel storage. They are comparatively low maintenance and have a lifespan of 15-25 years.
Electricity usually has an Energy related Products (ErP) rating of D, even though the energy efficiency at the point of use (used to run a boiler) is almost 99% to 100%. This is because the ErP rating factors in all the processes needed to produce and supply the fuel. Electricity generation involves the use of fossil fuels, and the transmission and distribution add to 2%-5% energy losses. That is why gas (a naturally occurring energy resource) has a low fuel factor of 1.0, and electricity has a fuel factor of 1.55.
Oil combi boiler costs
Oil combi boilers are the most expensive option, with costs ranging from £2,400 to £4,480. They are a good option for houses that are off the gas grid and have an energy efficiency level of more than 90%. They are ideal for homes with high heating and hot water demands as oil has high heat output because of its high energy density. Oil combi boilers have output sizes between 15kW and 40kW+.
| Supply cost | Installation cost | Total cost | Average cost | Average running cost (annual) |
|---|---|---|---|---|
| £2,400 – £4,480 | £1,000 - £2,000 | £1,600 – £6,500 | £4,200 | £1,380 |
Costs are estimates. Contact an installer for accurate quotes!
The monthly running costs of oil combi boilers are estimated to be around £100 to £130, therefore, the annual running costs would be between £1,200 and £1,560. This is less than electric boilers but higher than gas boilers. You have the option of storing oil in bulk and have flexibility with choosing the oil supplier. However, the carbon emissions and maintenance requirements can be significantly higher than other types of boilers.
How much does it cost to install a combi boiler
Combi boiler installation costs are around £1,000 - £2,000 , depending on the boiler type, labour costs, location, and installation complexity. It is a legal requirement to get a gas boiler installation done by a Gas Safe registered engineer, and an OFTEC-certified installer for oil boilers.
Boiler replacement costs and the time required are detailed in the following table.
| Installation type | Installation time | Cost |
|---|---|---|
| Combi to combi | 0.5 - 1 day | £1,600 - £6,000 |
| Conventional to combi | 2 - 3 days | £2,125 - £6,425 |
| System to combi | 1 - 2 days | £1,550 - £5,650 |
| Back boiler to combi | 2 - 3 days | £1,600 - £5,500 |
It is important to note that these costs are just estimates and it is recommended to contact an installer for a thorough evaluation and tailored quotes.
Are you worried about spending hours of your free time searching and calling different installers? We can make it easy for you. With GreenMatch’s service, you can get free, tailored quotes from the best local installers. All you need to do is answer a small 30-second questionnaire to get up to 3 non-obligatory quotes.
Click the button below to start!
- Quotes from local engineers
- Payment by finance available
- Save up to £975
Servicing costs for combi boilers
A boiler service can cost anywhere from £70 to £300 in the UK. The cost depends on the boiler type, fuel type and engineers rates.You can find further information about the servicing costs for different types of boilers in the table below.
| Boiler type | Cost |
|---|---|
| Gas boiler | £70 - £130 |
| Oil boiler | £80 - £300 |
| Electric boiler | £60 - £120 |
Costs are estimates based on our team’s research. These prices include all boiler types (combi, system and regular).
It is standard practice to get the boiler serviced once a year by a Gas-registered engineer for gas boilers and an OFTEC-registered technician for oil boilers. During the servicing process, the technician checks the different parts and the general functioning of the boiler.
Grants for combi boilers
There is no direct government grant for a combi boiler installation in the UK. There are some schemes, however, that help offset the costs partially or fully. You have to check your eligibility and then submit an application to avail the benefits.
Another thing to note is that the Boiler Upgrade Scheme, Home Energy Scotland Grant and Loan, and 0% VAT scheme are only for biomass boilers. The following table explains the different schemes available.
| Grant | Requirements | Running period | Potential savings |
|---|---|---|---|
| Boiler Upgrade Scheme | Must own and live in a rural, off gas grid property and replace a fossil fuel heating system. Valid EPC. | May 2022 to December 2027 | Covers up to £5,000 towards a biomass boiler |
| ECO4 scheme | Household receiving selected benefits (low income, low energy efficiency ratings) | July 2022 to March 2026 | Full and partial coverage for boiler replacement |
| ECO4 Flex scheme | Low-income households (under £31,000), those living with long-term health conditions | July 2022 to March 2026 | Full and partial coverage for boiler replacement |
| Affordable Warmth Scheme (Northern Ireland only) |
Low-income households (under £23,000) | January 2013 to March 2026 | Boiler replacement, if over 15 years old (criteria apply).Covers up to £7,500 |
| 0% VAT scheme | All buyers in England, Scotland, and Wales. Over 60s or receiving benefits in Northern Ireland. | April 2022 to March 2027 | 5 to 20% off the original cost (on biomass boilers) |
| Warmer Homes Scotland | Homeowner or private sector tenant in Scotland. For houses with a poor energy rating. | March 2023 to indefinite | Grant of up to £10,000 can include central heating improvements (i.e. new gas boiler or heat pump) |
| Home Energy Scotland Grant and Loan | Homeowners in Scotland. | Indefinite | A loan of £7,500 and a £7,500 grant for a biomass boiler |
| Northern Ireland Sustainable Energy Programme (NISEP) | Homeowner in Northern Ireland with income under £38,000 | Yearly (opens in April usually) | Different schemes offered under the umbrella programme |
| Nest Warm Homes Programme (Wales) | Homeowners/private renters in Wales on benefits. Houses with a poor energy rating. | 2011 to indefinite | Full and partial coverage for boiler replacement |
Find the best combi boiler prices near your area
Combi boilers come in different types and sizes, and it is important to choose the right boiler for your heating needs. Installing a combi boiler is not just a home upgrade, it is a financial investment that ensures better energy efficiency, low energy bills, a warm home and peace of mind.
That is why you need a reliable boiler installer who can help you make an informed decision. Thankfully, you do not have to waste hours searching for local installers on your own. Use GreenMatch’s service to get up to 3 free quotes by filling out a short 30-second form, and we’ll do the rest.
Click the button below to begin!
- Quotes from local engineers
- Payment by finance available
- Save up to £975
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