We get asked this question more than any other. Usually by someone who's read three contradictory articles, seen a horror story on a forum, and wants a straight answer.
So here it is. For most homes currently on mains gas, a heat pump is worth it in 2026, primarily because the £7,500 BUS grant slashes the upfront cost to a level where the running cost savings, even modest ones, produce a reasonable payback. Without the grant, the maths are much harder to justify for an average home.
That's the honest position. Now let's show the working.
The Maths for a Typical Semi
Take a three-bedroom semi-detached house, the most common home type in England. EPC band D, cavity wall insulation, double glazing, 12,000 kWh of annual heat demand. Currently heated by a gas boiler.
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Fuel prices are April 2026 Ofgem price cap rates. SCOP of 3.2 is a conservative real-world average from MCS data. SCOP of 3.5 is what a well-designed system in a reasonably insulated home achieves.
At an SCOP of 3.2, the heat pump costs roughly the same to run as the gas boiler. At 3.5, you save about £67 a year. Neither figure is life-changing.
So why bother?
Because the upfront cost after the grant is £4,500 to £8,500, and the system lasts 15 to 20 years. Even at £67 per year in savings, a £5,000 net investment pays back in about 12 years with the rest as pure gain. And that's the conservative scenario. Three things can improve it significantly:
Solar panels. If you generate even 2,000 kWh of your own electricity per year, that's roughly £490 of free fuel for the heat pump. The combined payback accelerates dramatically. See our guide on solar panels vs heat pumps for the full comparison.
Time-of-use tariffs. Octopus Go and similar tariffs offer electricity at 7p to 10p per kWh overnight. Run your heat pump on cheap overnight electricity and the annual heating cost drops to £375 to £535, saving £370 to £530 compared to gas.
Rising gas prices. Gas has been volatile since 2022. Every penny per kWh increase in gas price makes the heat pump look better. Electricity prices matter too, but the 3.5x efficiency multiplier means gas price rises hurt boiler owners more.
When They're NOT Worth It
Here's the section most heat pump guides skip because it doesn't help sell installations. We think you deserve the honest picture.
You're in a Well-Insulated Home with Cheap Gas
If your home is already band B or C, your gas bills are low, and you've got a relatively new condensing boiler, the financial case for a heat pump is weak. Your current system is already efficient. The running cost saving might be £0 to £50 per year, which means even after the grant you're looking at a payback period of 15+ years.
You might still choose a heat pump for environmental reasons, and that's valid. But don't expect it to save you money in this scenario.
You Live in a Tiny Flat
A one-bedroom flat with low heat demand might use only 5,000 kWh of heat per year. The annual running cost difference between gas and a heat pump could be under £30. Meanwhile, you need somewhere to put the outdoor unit (balcony? shared courtyard?) and the installation cost is still £8,000+ before the grant. The numbers don't stack up for very small properties with low heating bills.
Air-to-air units (like a wall-mounted split system) can make sense for supplementary heating in flats, but they don't qualify for the BUS grant and don't replace your boiler.
Your Home Has No Insulation and Single Glazing
A heat pump in a draughty, uninsulated house will work, but it'll work hard. The SCOP drops because the system has to run at higher flow temperatures to compensate for the heat escaping through walls and windows. You might see an SCOP of 2.5 instead of 3.5, which pushes annual running costs above what you'd pay for gas.
The right move here is to insulate first, then install the heat pump. Cavity wall insulation costs £500 to £1,500. Loft insulation is £300 to £600. Both could be funded through ECO4 if you qualify. Doing the insulation first means a smaller, cheaper heat pump that runs more efficiently.
You're Replacing Oil or LPG (Actually, Do Get One)
This is the opposite case. If you're on oil or LPG, a heat pump is almost certainly worth it. Oil costs roughly 7p to 9p per kWh and LPG 8p to 11p per kWh, both significantly more than mains gas. The running cost savings are £200 to £600 per year compared to oil, and more against LPG. Payback after the grant: five to eight years.
Oil and LPG homes are exactly the properties the BUS grant was designed for. If this is you, stop reading and open the eligibility checker.
Running Costs vs a Gas Boiler: The Detail
The table above showed the headline numbers. Here's what moves the needle in practice.
Flow temperature matters more than brand. A heat pump running at 35°C flow temperature will achieve a much higher COP than one running at 55°C. If your radiators are big enough (or you have underfloor heating), lower flow temperatures are possible. This is why the survey and system design matter so much. See our installation guide for what to expect.
Hot water is the efficiency killer. Heating your home to 21°C is efficient. Heating your hot water cylinder to 50°C to 55°C is less efficient because the heat pump has to work harder at higher temperatures. Homes with high hot water demand (large families, multiple bathrooms) will see a lower overall SCOP than the headline figures suggest.
The standing charge gap is closing. Electricity standing charges are higher than gas standing charges. You'll still pay a gas standing charge if you keep the gas supply connected (for a hob, say). If you go fully electric and disconnect gas, you save the gas standing charge entirely, roughly £100 to £120 per year.
The Grant Makes the Difference
Let's be blunt about this. Without the Boiler Upgrade Scheme grant of £7,500, the economics of a heat pump for an average gas-heated home are marginal at best. A £13,000 installation saving £67 per year takes nearly 200 years to pay back on running costs alone. Nobody is making that investment on pure economics.
With the grant, a £5,500 net cost saving £67 per year pays back in about 12 years. Add solar or a cheap tariff and that drops to 5 to 8 years. Add the environmental benefit and the future-proofing against gas price rises, and the case becomes solid.
The BUS grant is currently funded until 2028, per GOV.UK. There's no guarantee it'll be extended at the same level. If you're considering a heat pump, the grant is the single biggest factor in whether the numbers work.
Check which heat pump brands suit your property and budget. Then open the eligibility checker. Two minutes. You'll see exactly what you qualify for.
For a typical gas-heated three-bed semi, the annual saving is modest: roughly £0 to £100 depending on your system's efficiency. The savings are larger if you're replacing oil or LPG (£200 to £600 per year), if you have solar panels, or if you use a time-of-use electricity tariff with cheap overnight rates. The BUS grant is what makes the overall investment worthwhile, not the annual running cost saving alone.
What is the payback period for a heat pump?
After the £7,500 BUS grant, payback for a gas-to-heat-pump switch is roughly 10 to 15 years on running cost savings alone. With solar panels or a time-of-use tariff, that drops to 5 to 8 years. Without the grant, payback stretches beyond 20 years for most gas-heated homes, which is why the grant is so important to the economics.
Are heat pumps worth it if I already have a new boiler?
Probably not right now. If your condensing boiler is less than five years old and working well, the financial case for switching immediately is weak. You'd be spending £4,500 to £8,500 (after the grant) to replace a system that already works efficiently. It makes more sense to plan the switch for when your current boiler reaches end of life, typically 12 to 15 years.
Do heat pumps work in older houses?
Yes, but insulation matters. An older home with solid walls and single glazing will need the heat pump to work harder, reducing efficiency and increasing running costs. The best approach is to insulate first (loft, cavity walls, draught-proofing) and then install the heat pump. Some of that insulation work may be funded through ECO4 if you qualify.
Will a heat pump increase my property value?
Evidence is still emerging, but early data suggests homes with heat pumps and good EPC ratings sell for a premium. A 2023 study by the Department for Energy Security and Net Zero found that improving a home from EPC band D to C added roughly 3% to 5% to its value. A heat pump that pushes your rating up one or two bands could add £5,000 to £15,000 to a typical property price.