Blog>Cost Guides>How much does it cost to replace a boiler with a heat pump?
Last updated: 27 June 2025
How much does it cost to replace a boiler with a heat pump?
Switching from an oil or gas boiler to a heat pump is a great way to lower your energy bills and reduce your impact on the environment. But how much does it cost to replace a boiler with a heat pump?
Fast Facts
Heat pump costs range from £2,000 - £50,000 for supply and installation
You'll often need to budget extra to replace your radiators and pipework
You could get up to £7,500towards your new heat pump from the Boiler Upgrade Scheme (BUS)
Always hire an MCS-certified heat pump installer
Keen to reduce your energy bills? Make your home more eco-friendly? Or invest in a future-proof heating system?
A heat pump could be the solution you’re looking for. In this guide, we’ll take a look into the average cost to replace a boiler with a heat pump, to help you budget.
How much does it cost to replace a boiler with a heat pump?
The average cost to supply and install a heat pump ranges from £2,000 - £50,000, depending on what kind of heat pump you’re after.
| Item | Unit | Lower range | Higher range | Average cost |
|---|---|---|---|---|
| Air-to-water air source heat pump (5kW - 17kW) | Supply and installation | £11,000 | £20,000 | £15,000 |
| Air-to-air air source heat pump (5kW) | Supply and installation | £2,000 | £4,000 | £3,000 |
| Ground source heat pump (4kW - 12kW) | Supply and installation | £18,000 | £50,000 | £34,000 |
| Options | ||||
| (a) Upgrade to larger radiators | 10 radiators | £2,000 | £5,000 | £3,000 |
| (b) Underfloor heating | £5,000 | £15,000 | £10,000 | |
| Insulation upgrades | ||||
| Cavity wall insulation | £500 | £3,000 | £2,000 | |
| Roof insulation (blanket roll) | £500 | £2,000 | £1,500 | |
| Floor insulation | £1,000 | £5,000 | £3,000 | |
| Last updated: May 2024 Our costs are ballpark averages - get a local tradesperson to quote now | ||||
If you’re looking to replace an oil or gas boiler, you’ll usually need to budget for more than just installing your new heat pump. You’ll also need to modify your home so that your new heat pump can work effectively.
This brings us to…
How much does it cost to switch from a gas boiler to a heat pump?
Replacing a gas boiler with a heat pump will usually cost more than installing a heat pump in a new build.
This is because your home is currently set up to be heated by a boiler. But boilers and heat pumps work differently. For instance, a heat pump will work at lower temperatures and will take longer to produce heat.
For this reason, you’ll often need to buy new radiators and replace pipework to make sure your new heat pump can heat your home just as effectively as a boiler. Generally, radiators for a heat pump system will need to be two and a half times larger than for a gas combi boiler to provide the same heat output.
You’ll typically need to budget around £3,000 to upgrade to larger radiators or £10,000 for underfloor heating.
How much does it cost to replace an oil boiler with a heat pump?
Replacing an oil boiler with a heat pump will come with the same additional costs as switching from a gas boiler.
Again, you’ll usually need to budget for new radiators or underfloor heating. And you might need to replace your pipework too.
On top of this, it’s worth bearing in mind that heat pumps work best in properties that are insulated to a high standard. If not, it can be difficult for a heat pump to maintain the desired temperature inside.
Of course, oil boilers are often found in rural homes such as farmhouses and cottages, which can be poorly insulated. So, you may find you need to invest in upgrading your property’s insulation before replacing your oil boiler with a heat pump.
You’re looking at around £2,000 to upgrade your wall insulation, £1,500 to upgrade your loft insulation, or £3,000 to improve your floor insulation.
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How does the type of heat pump affect your costs?
How much it costs to replace a boiler with a heat pump can vary widely depending on lots of different factors. However, the main one is probably the type of heat pump you choose.
Domestic heat pumps broadly fall into two groups.
1. Air source heat pumps
Air source heat pumps use energy from the outside air to heat the air inside a building.
The most common kind is air-to-water. These systems are designed to heat both your home and water, and typically cost between £11,000 and £20,000 for supply and installation.
Alternatively, you can choose an air-to-air system. These typically cost less – between £2,000 and £4,000 for supply and installation. But they’ll only heat your home and won’t provide hot water. So, you’ll still need another way to heat water in your property.
Air source heat pump costs in the UK 2026
If you’re looking for a clean way to heat your home while saving money on your energy bills, then an air source heat pump could be for you. Keep reading to find out more about the average air source heat pump cost in the UK.
2. Ground source heat pumps
Ground source heat pumps are more expensive than air source heat pumps. However, they’re more efficient. They harness energy from the ground and use it to heat your home and water.
There are two main types of ground source heat pumps – horizontal and vertical.
With horizontal ground source heat pumps, the pipework is buried horizontally in shallow trenches. This is the cheapest option but requires a lot of space.
On the other hand, if you live in a smaller property, the pipework will need to be buried in vertical boreholes. The groundwork for this is usually twice as expensive as it is for trenches.
With the cost of groundworks factored in, you can expect to pay anywhere from £18,000 to £50,000 to get a ground source heat pump installed.
Ground source heat pump: Cost breakdown 2026
With the growing popularity of green energy solutions in the UK, many homeowners are looking for alternative heating options for their homes – such as ground source heat pumps. In this guide we look at the average ground source heat pump cost in the UK.
Other factors affecting the cost to replace a boiler with a heat pump
Aside from the type of heat pump you choose, several other factors can affect how much it costs to switch from a boiler to a heat pump. These include:
The size of your property
How well-insulated your property is
The brand of heat pump
Your heat pump’s performance and efficiency
Your desired room temperature
Radiator upgrades or underfloor heating
Whether you’re eligible for grants or funding
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Help towards the cost of replacing a boiler with a heat pump
The government wants to encourage homeowners to switch from gas or oil boilers to more eco-friendly heating methods — like heat pumps.
With that in mind, there are a number of different schemes available to potentially help you with the cost of switching.
The main one available in the UK is the Boiler Upgrade Scheme (BUS).
This offers grants of up to £7,500 for homeowners in England and Wales who want to switch to a heat pump. Most homes are eligible for the scheme, which is set to run until 2025.
Energy grants available in 2026
The latest information from the government is that they are investing £12 billion in Help to Heat schemes to make sure homes are warmer and cheaper to heat. This includes the: Boiler Upgrade Scheme Energy Company Obligation (ECO) This funding is not delivered directly by the government, but through
Is it worth replacing a boiler with a heat pump?
Yes! Even though switching from a boiler to a heat pump is more expensive than replacing your boiler like-for-like, you’ll make significant savings in the long run.
In fact, switching to a heat pump comes with tons of benefits. These include:
Cheaper energy bills
Lower carbon emissions
Very little maintenance
Renewable heating system
Can heat air and water for your home
Installation costs can be subsidised by the government (if your home is eligible)
How much can you save by switching from a boiler to a heat pump?
Replacing a boiler with a heat pump will mean you can generate your own energy. Not only does is this a great way to make your home more eco-friendly. But it will also massively cut down your energy bills!
Here’s how much an average three-bedroom property could save each year by upgrading to an air source heat pump (according to the Energy Saving Trust).
| Item | Lower saving range | Higher saving range |
|---|---|---|
| Replacing a gas boiler | £8 | £385 |
| Replacing an oil boiler | £15 | £455 |
| Replacing an LPG boiler | £50 | £460 |
| Last updated: May 2024 Our costs are ballpark averages - get a local tradesperson to quote now | ||
Calculating how much it will cost to replace a gas boiler with a heat pump
As you can see, the cost to replace an oil or gas boiler with a heat pump will vary massively based on lots of different factors — from the size of your home to the type of heat pump you need.
With that in mind, the best way to calculate how much it will cost to switch from a boiler to a heat pump is to get quotes from certified installers near you.
It's a good idea to get at least three quotes for heat pump installation. That way, you can get a feel for the right company for the job. Plus, you can make sure you’re getting a fair and competitive price for the work.
Key takeaways
Heat pump installation costs can range from £2,000 to £50,000
You’ll usually also need to factor in the cost of replacing radiators and pipework
The Boiler Upgrade Scheme (BUS) could contribute up to £7,500 towards the cost of replacing a boiler with a heat pump
Always hire a heat pump installer who is certified by the Microgeneration Certification Scheme (MCS)
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