Replacing a boiler with a heat pump - complete transition guide
Heat pumps are rapidly gaining popularity in the UK - between January 2024 and May 2025, over 65,000 have been installed as homeowners switch from traditional boilers(1). Whatever system you currently use - combi, gas, or oil - you can upgrade to an air source heat pump to start saving. In this guide, we'll show you how to start your journey towards a low‑carbon home.
Why replace a boiler with an air source heat pump?
Replacing a traditional boiler with a heat pump offers a range of compelling benefits:
- More efficient - an air source heat pump is over 300% more efficient than a standard gas boiler(2). This means it makes over three units of heat for every unit of electricity it uses; in contrast, an A-rated gas boiler loses 10% of the energy it uses as waste.
- Save money on electricity bills - you could save money on your heating bills in the long term. The amount you save varies depending on the type of boiler you’re replacing, but as an example, you could save up to £700 a year by switching from an old G-rated LPG boiler to an air source heat pump(3). You can also take advantage of our air source heat pump tariff for twice daily discounts on your electricity, saving you £164!(4)
- Cut your carbon footprint - heat pumps use renewable energy by extracting heat from the air outside to generate heat for your home (even when temperatures are well below freezing!). They can even reduce your carbon footprint by around 13% a year(5).
How the boiler to heat pump transition works
Swapping out your boiler for a heat pump might sound daunting, but it’s more doable than you think. Let's break down the process, step by step:
Before your installation
Get a quote
We’ll build you a quote around the specifics of your home, looking at the details that matter most to create the perfect system design for your needs
Apply for the grant
If you live in England or Wales, we’ll apply for a £7,500 grant through the Boiler Upgrade Scheme for you and deduct this from your final costs. If you live in Scotland, you’ll need to apply directly through Home Energy Scotland.
The installation process
The design process for an air source heat pump takes around 12 weeks, as each system is tailored to the home. Below we outline the typical process; however, individual installations may differ depending on specific needs.
Day 3
Removing your boiler
Our installers do everything they can to install the heat pump system before removing your boiler, ensuring you’re not without heating or hot water for long.
Day 4
Commissioning your system
Your installer will commission your system, ready for use. They may purge air from the system and check the radiator and water temperatures. They’ll show you how to use your new system and controls.
Can a heat pump replace any boiler?
A heat pump can replace a combi, conventional (standard), or system boiler regardless of whether it runs on gas, oil or LPG. Heat pumps work with standard central heating systems, including radiators and underfloor heating. They heat water just like a boiler does, but instead of burning fuel, they extract heat from the outside air, making them a more efficient, environmentally friendly option for both heating and hot water.
Costs of replacing different boiler types with a heat pump
Now that you know a heat pump can replace a combi, conventional, or system boiler, the next question is: what will it cost? Air source heat pump costs can vary depending on the type of new heating system you’re installing. Let’s compare the current average prices of installing different boiler types(6) with the cost of installing an air source heat pump:
| Type of heating system | Average cost (including installation) |
| Combi boiler | £2,000 - £3,500 |
| System boiler | £1,600 - £4,500 |
| Conventional boiler | £1,500 |
| Air source heat pump | £4,100*(7) - over £10,000 |
*£4,100 Price assumes reuse of a suitable existing hot water cylinder. Homes requiring a new cylinder will have an additional cost.
Although upfront costs are high, air source heat pump grants are available from the government to help cover the cost of switching to this low-carbon alternative. You’re likely to save money on your energy bills in the long run because heat pumps are 3 to 4 times more efficient than boilers, and with EDF’s exclusive heat pump tariffs, you’ll be able to save on electricity costs too.
Are there any incentives or grants available?
You could be eligible for financial support from the government to help with the costs of installing an air source heat pump. Grants of up to £7,500 are available in England and Wales, and up to £9,000 in some areas of Scotland. If you receive government benefits, you may qualify for additional support through the ECO4 scheme.
If you live in England or Wales, EDF heat pumps will apply for the grant on your behalf through the Boiler Upgrade Scheme and subtract the amount from your overall installation cost. This grant will cover installations before the end of March 2028. We want you to be fully aware of how much you’ll be paying before we install your heat pump, so we’ll work with you to make sure you qualify for the grant beforehand.
If you live in Scotland, you’ll need to apply for the grant from Home Energy Scotland Scheme directly before EDF heat pumps can install your heat pump.
Ready to upgrade your heating?
Enjoy reliable home heating, plus 7 years of free servicing and warranty.(8)
Want to stick to a boiler?
Not ready to make the switch? If a new boiler seems like a better option for you, we can still help. We work with trusted partners across the UK who use Gas Safe registered engineers to install your new boiler safely.
Why choose EDF heat pumps?
As an accredited Which? Trusted Trader, we’re committed to providing exceptional quality, reliability, and customer service. When you choose EDF Heat Pumps, you’re choosing a trusted installer that delivers outstanding performance and value.
From the moment we first made contact we EDF heating we found a team that was knowledgeable and helpful. From first discussion through to site visit, design and install the team were courteous and nothing was to much trouble even when small tweaks were required. The install team were professional and tidy and accommodated any issues as they arose.
May 16, 2025
EDF has been lightning fast in quoting, assessing, and designing our system. We're in the middle of a renovation so this responsiveness has been much appreciated.
September 16, 2025
FAQs
Will heat pumps replace all boilers in the UK?
You may have heard that the UK government were considering banning gas boilers in 2025; however, this has been withdrawn. There are no plans for a gas boiler ban at this moment in time, so heat pumps won’t replace all boilers in the UK. Nonetheless, air source heat pumps are gaining popularity and could help you save both cash and carbon.
Are there any limits on what homes can have a heat pump system?
Most homes are suitable for a heat pump (including flats!) - you just need enough space outside (around 2m x 1m) for the heat pump and space inside for the water tank. Your installer may also recommend insulation and radiator upgrades; they’ll make sure you get a system that’s designed specifically for your home.
How does switching from a gas boiler to a heat pump affect my carbon footprint?
Air source heat pumps use electricity to draw heat from the outside air to warm your home. Because they don’t rely on gas or other fossil fuels, they produce no direct carbon emissions from combustion. To go even greener, you can power your heat pump with one of our low-carbon electricity tariffs - EDF is the UK’s biggest generator of zero-carbon electricity(9), so switching to a heat pump with us means you’re choosing cleaner energy from the source. In fact, switching to an air source heat pump could reduce your carbon footprint by around 13% annually!(5)
Do I need insulation upgrades before replacing a boiler with a heat pump?
Heat pumps are most efficient in well-insulated homes, as the heat loss through the walls, floor and ceiling is reduced, so your heat pump doesn’t need to work as hard to keep your home warm. If you live in a home that isn’t well insulated, for example, an older property, don’t worry! Insulation might be recommended, but it’s not compulsory. Our installers will design a system that works best for your needs.
Do I need radiator upgrades before replacing a boiler with a heat pump?
Heat pumps work better with larger radiators as they have more surface area to emit heat and warm your home. Low-temperature heat pumps, in particular, may need larger radiators to work at their maximum efficiency. That said, a heat pump can still work with regular radiators, so a radiator upgrade isn’t an absolute necessity.
Does a heat pump require more maintenance than a gas boiler?
Heat pumps and boilers need the same level of maintenance. Like a boiler, you should have your air source heat pump professionally serviced annually to ensure it’s still working at its best and to maintain warranty coverage. Heat pumps often have a longer lifespan than boilers (15-20 years or more, compared to 10-15 years for boilers), making them a better long-term investment than a boiler.