The short version
| Advantages | Drawbacks | |
|---|---|---|
| Money | A grant of £7,500 for an eligible system in England and Wales; several units of heat for each unit of electricity | Costs more to install than a boiler, even after the grant |
| The home | One system for heating and hot water; no flue, no fuel deliveries | Needs a hot water cylinder, an outdoor unit and sometimes larger radiators |
| Comfort | Steady, even warmth through the day | Warms up more slowly than a boiler |
| The work | Designed for your home from a heat-loss calculation | Several days of installation; not an emergency fix |
The advantages
It is far more efficient than a boiler
A boiler burns fuel, and can never give out more heat than the fuel contains. A heat pump moves heat from outside to inside, using electricity to do it, so it delivers several units of heat for each unit of electricity. That efficiency is the reason the technology exists, and it is why running costs can compete with gas even though electricity costs more per unit.
There is a grant
In England and Wales, the Boiler Upgrade Scheme pays £7,500 towards an eligible air source or ground source heat pump, with no income test. Eligible off-gas homes replacing oil or LPG can get up to £9,000, for applications properly made by 31 March 2027. Your installer applies and takes the grant off the quote.
Air-to-water or ground source
£7,500
The standard grant for an eligible air source (air-to-water) heat pump.
Air-to-air
£2,500
Residential properties only. Air-to-air systems are not eligible in non-residential buildings.
Installed heat pumps also carry 0% VAT until 31 March 2027. Every grant value, with its conditions, is on our heat pump grants page.
It suits off-gas homes especially well
Homes heated by oil, LPG or direct electric heaters usually have the strongest case. They are usually replacing a more expensive fuel, though oil and LPG prices move a lot. Oil and LPG homes also stop depending on deliveries and a tank, and may qualify for the higher grant. Our guides to replacing an oil boiler, an LPG boiler and storage heaters cover each case.
The warmth is steadier
A heat pump runs for longer at a lower temperature, so rooms stay at an even temperature instead of swinging between hot and cool. Many people find that more comfortable than the bursts of a boiler, once they are used to it.
No combustion in the house
A heat pump burns nothing. There is no flue, no flue gas and no fuel stored on site. If nothing else in the home uses gas, you can ask your supplier about removing the gas meter, which ends the gas standing charge.
It works with solar panels and smart tariffs
Because it runs on electricity, a heat pump can use power from solar panels, and hot water can be heated at cheaper times of day on a time-of-use tariff. Neither is required, but both can reduce what it costs to run.
The drawbacks
The upfront cost
A heat pump installation costs more than a like-for-like boiler swap, and the grant does not always close the gap. The price depends mostly on the home: whether a cylinder is needed, how many radiators change, and what pipework and electrical work are involved. Two quotes for the same house can differ by a lot, for good reasons.
It needs space
Most heat pumps need a hot water cylinder indoors and a unit outdoors with clear airflow. In a home with a combi boiler, the cylinder is new, and somewhere has to be found for it. Flats and small terraces are where this bites hardest.
Some radiators may need to change
A heat pump heats radiator water to a lower temperature than a boiler. A radiator that was only just big enough may need to be larger. The heat-loss survey shows which rooms, so adequate radiators are left alone.
Running costs are not guaranteed to fall
Electricity costs more per unit than gas. A well-designed system is efficient enough to make up for that; a poorly designed one may not be. This is the drawback most within your control, because it comes down to design quality. Our heat pump running costs guide explains what to check.
It is a different way of heating
A heat pump is not switched on for an hour in the morning and an hour at night. It runs gently for long periods. People who run one like a boiler tend to be disappointed, so it is worth understanding before you commit.
It is not an emergency replacement
A heat pump needs a survey and a design before installation, and the grant application is normally made first. If the boiler has failed in January, that is rarely practical. Planning ahead, while the old system still works, is what makes a heat pump a real option.
When a heat pump is worth it
- You own the home and expect to stay for some years.
- You heat with oil, LPG or electric heaters, or your gas boiler is ageing and you would rather choose than react.
- There is a hot water cylinder already, or space for one.
- There is a sensible place outside for the unit.
- Other work is planned, such as an extension, new floors or a rewire, that the installation can be folded into.
When it may not be worth it yet
- The heating has failed and the house needs heat this week.
- There is genuinely nowhere for a cylinder or an outdoor unit.
- You are likely to move soon.
- You rent the home. The decision and the grant application belong to the owner.
None of these is permanent. A boiler fitted now does not rule out a heat pump later.
The design matters more than the brand
Most disappointing heat pumps are badly designed systems, not bad machines. Before you compare prices, ask every installer for the room-by-room heat-loss calculation and the water temperature the system is designed to run at. A quote that arrives without anyone measuring the rooms is a warning sign.
How to decide for your own home
- Check the basics. Our guide to whether a home is suitable for a heat pump covers heat loss, radiators, hot water, outdoor space and electrics.
- Check the grant. The eligibility page sets out who can use the Boiler Upgrade Scheme.
- Get a survey. A heat-loss survey tells you what the house needs and gives you a quote you can rely on.
- Compare like with like. If you heat with gas, our heat pump vs gas boiler guide sets the two side by side.
Lower-income households
Some households in England can get a heat pump and insulation funded through the Warm Homes: Local Grant. Our eligibility check covers it alongside the Boiler Upgrade Scheme and ECO4.
Check your property
Three quick answers take you to our eligibility check with them already filled in. It is free, and nothing is sent until you choose to send it.
