Should I get a heat pump or a new boiler?

When a boiler gets old or breaks down, most people now face a question their parents never had to ask: replace it with another gas boiler, or switch to a heat pump? There is no single right answer. A gas boiler is cheaper to buy and quick to fit. A heat pump costs more up front, comes with a large grant, and can be cheaper to run, but only if it is designed and installed well.

This guide sets out what each costs to fit, what each costs to run on today's energy prices, which homes suit a heat pump, the grant and planning rules, and how to get quotes you can compare. Every figure is sourced, and where we have done the maths ourselves we say so.

The short answer

A gas boiler is usually the right choice when the old one has failed in winter and you need heat quickly, when you expect to move within a few years, or when a survey shows your home would need a lot of work to suit a heat pump. A heat pump is worth serious thought when your boiler is ageing but still working, so you have time to plan, when you are on oil, LPG or electric heating, or when you want to stop burning gas and are staying put.

If your boiler has only just stopped, start with our guide on what to do when your boiler breaks down. A repair can buy you the time to make this decision properly, and our guide to boiler repair costs shows when a repair stops making sense.

What each costs to fit

A new gas boiler

The average gas boiler including installation is £3,700, according to the Energy Saving Trust, as reported by Which? in September 2026. Which?'s own boiler price guide gives a wider range of around £1,400 to £7,000, because the price depends on the type of boiler, whether it stays in the same place and how much pipework changes. A like for like combi swap sits at the lower end. Moving the boiler, converting a system with a tank to a combi or adding a new flue costs more.

An air source heat pump

Government statistics put the average air source heat pump installed under the Boiler Upgrade Scheme from October to December 2025 at £13,431 for an average 8.4kW unit, reported by Which? in April 2026. After the £7,500 grant, a typical household paid just under £6,000. Nesta's analysis of the same scheme data gives a median of £13,041 for 2025 to 2026, almost unchanged on the year before.

That price usually covers the outdoor unit, a hot water cylinder, any radiators that need upsizing, pipework, controls and commissioning. Ground source heat pumps cost considerably more because of the digging or drilling, and suit homes with a large garden or space for a borehole.

No VAT on an installed heat pump, for now

HMRC applies a zero rate of VAT to heat pumps supplied and installed in homes in Great Britain from 1 May 2023 to 31 March 2027. From 1 April 2027 it is due to go back to 5 percent unless the government extends it.

The Boiler Upgrade Scheme grant

The Boiler Upgrade Scheme is open to homes and small businesses in England and Wales. The current grants are:

• £7,500 towards an air source heat pump
• £7,500 towards a ground source heat pump
• £2,500 towards an air to air heat pump
• £5,000 towards a biomass boiler
• An extra £1,500 towards an air or ground source heat pump for homes heated by oil or LPG with no mains gas connection, until March 2027

To be eligible, you must own the property (second homes and rented homes count), be replacing a fossil fuel system such as gas, oil, LPG or electric heating, and use an MCS certified installer. The installer applies for the grant and takes it off your bill. The heat pump must be installed and commissioned within 120 days of the application. New builds still being built by the developer are not eligible. The scheme is popular: Nesta counts 30,600 air source heat pumps installed through it in 2025 to 2026, up 24 percent on the year before, and almost 80,000 heat pumps since it opened in April 2022. Scotland has its own support through Home Energy Scotland.

What each costs to run

This is where most of the confusion lies, so here is the reasoning in plain steps. A gas boiler turns most of the gas it burns into heat, typically around 85 to 90 percent for a modern condensing boiler. A heat pump moves heat from the outside air into your home, producing more heat than the electricity it uses. Its seasonal coefficient of performance (SCOP) measures this across a whole year: a SCOP of 3 means 3 kWh of heat for every 1 kWh of electricity.

From 1 October to 31 December 2026, the Ofgem price cap averages 26.32p per kWh for electricity with a 54.83p daily standing charge, and 7.97p per kWh for gas with a 29.68p daily standing charge, paying by direct debit. Electricity costs about 3.3 times as much per unit as gas, so a heat pump has to do better than that to win.

A worked example

Which? uses a home that burns 11,500 kWh of gas a year in an 85 percent efficient boiler. That home needs about 9,775 kWh of heat. On today's price cap, our calculation of the yearly unit cost is:

The break even point is a SCOP of about 2.8. Which? reached a similar figure, 2.9, using the electricity prices at the time it wrote. Two things move the answer further towards the heat pump. First, if you take out the gas supply altogether you stop paying the gas standing charge, which is about £108 a year at the current rate. Second, specialist heat pump and time of use tariffs charge less for electricity at certain times, and Which? found a heat pump can still save money at a SCOP as low as 2.0 on such a tariff, provided you can run it in the cheaper hours.

The lesson is that the quality of the installation matters more than the badge on the box. A well designed system running at low water temperatures can reach a SCOP of 3.5 or more. A badly sized one with small radiators may struggle to reach 2.5 and cost more to run than the boiler it replaced.

Is your home suited to a heat pump?

Most homes can take a heat pump, but some need more work than others. A good installer will tell you honestly. The things that matter are:

• Insulation. A heat pump runs best when the house holds its heat. Loft and cavity wall insulation are usually the cheapest improvements and help whichever system you choose. If you have damp or condensation problems, sort the cause first, as explained in our guide on condensation, damp and mould.
• Radiators. A heat pump heats water to a lower temperature than a boiler, so some rooms may need larger radiators. A room by room heat loss calculation shows which ones.
• Space for a cylinder. Unlike a combi boiler, most heat pumps store hot water in a cylinder, so you need a cupboard for one.
• Space outside. The outdoor unit needs a spot with good airflow, usually against an outside wall or in the garden, and away from bedroom windows where possible.
• Electrics. Older consumer units sometimes need upgrading. If your wiring is very old, our guide to rewire costs explains the signs.

Planning permission and the rules

In England, most air source heat pumps do not need planning permission. Since 29 May 2025, they count as permitted development without the old rule that they had to be at least one metre from the boundary. The unit can be up to 1.5 cubic metres, a detached house can have two, and the installation must meet the MCS noise standard. The Planning Portal explains the conditions. You may still need permission for a listed building, in some conservation areas, or where the council has removed permitted development rights. Wales, Scotland and Northern Ireland have their own rules.

There is no ban on gas boilers in existing homes. You can replace a gas boiler with a new gas boiler, and no law requires you to remove a working one. The Future Homes Standard, which comes into force on 24 March 2027, applies to new homes in England, which will need low carbon heating such as a heat pump.

How to get quotes you can compare

The two jobs are done by different specialists, so get a quote from each.

• For a heat pump, use an installer on the MCS register, otherwise you cannot get the grant. Ask for a room by room heat loss calculation, the recommended size, the expected SCOP and flow temperature in writing, the radiators being replaced, where the unit and cylinder will go, and the price before and after the grant.
• For a boiler, use an engineer on the Gas Safe Register. Ask for an itemised price, the warranty length and whether a system flush and a filter are included. Once fitted, book a yearly service, covered in our guide on boiler service costs. Landlords also need a yearly gas safety certificate.

Get at least two or three quotes for whichever you choose, and check the business before you pay a deposit. Our guide on how to check a tradesperson is genuine covers registers, insurance and the warning signs.

Find a local heating engineer

Whether you are leaning towards a heat pump or a new boiler, post your heating job free and hear back from a local heating engineer. Say what heating you have now, how old it is, and whether you want a heat pump quote, a boiler quote or both. You pay the tradesperson directly, and there is nothing to pay online.

Or browse local businesses: heating engineers in Birmingham, heating engineers in Coventry, heating engineers in Wolverhampton, heating engineers in Walsall, heating engineers in Worcester or gas engineers in Birmingham. You can also browse all our home advice.