DATA-BACKED GUIDE · UPDATED JULY 2026
Air source heat pump running costs in the UK: what to expect per year
Most homeowners fixate on the fitting bill and forget to ask what a heat pump costs to run once it's switched on. That annual figure hinges on three things: your electricity tariff, how well the house holds heat, and the flow temperature your installer dials in. The real prices on this page come from people who have shared their actual bills, so you can weigh a pump against a gas boiler with real numbers instead of a salesman's estimate.
The quick version
- Heat pumps run on electricity, so your unit rate and any dedicated heat pump tariff swing the yearly cost more than anything else about the system itself.
- A warm, well insulated home running at a low flow temperature is far cheaper to heat than a draughty one with undersized radiators.
- Two near-identical houses can end up with very different bills. The gap is usually down to how the system was commissioned, not the hardware.
- The £7,500 Boiler Upgrade Scheme grant lowers the upfront cost of an air source heat pump and brings the payback period forward, but it does nothing for the running cost itself.
- Fitting a heat pump counts as an energy-saving measure, so it carries 0% VAT until 2027, which shrinks the install bill you're trying to recoup.
- A proper room-by-room heat loss survey before install matters more to your future bills than the brand of pump you end up with.
What people actually paid
Real prices, in people's own words
- £2,200“Mine was £2.2k after BUS from Octopus, 8 rads.”
- £2,900“I paid £1300 (ASHP), £1000 for cylinder and another £600ish for stuff.”
- £3,000“I paid roughly £10500 for a 7kW aurotherm plus with 300l UVC, no buffer tank as one zone and full install. Minus the Home Energy Scotland Grant (£7500) I paid £3000”
- £6,500“My Octopus install cost around £11,500 and I paid £6,500 after the grant”
- £8,500“I got a full package from coolenergy, heatpump, buffer, 300l HWC, carel controller, glycol, the works. That was £6300 after vat reclaim.”
- £12,000“We where charged 12k minus the grant for an 11 KW Mitsubishi”
Genuine amounts posted publicly. We publish the price and the quote, never the person.
Why the price varies so much
The running cost gap between two identical houses can be huge, and it usually comes down to detail rather than the pump itself. A pump running at a low flow temperature through big radiators or underfloor pipes sips electricity, while the same unit forced up to a much higher flow temperature to feed small old radiators drinks it. Your seasonal efficiency, often quoted as an SCOP, decides how many units of heat you get for each unit of power, and that shifts with the weather and how the system was commissioned in the first place. A standard variable electricity tariff will cost you far more than a smart tariff with a cheap overnight window, so two households paying different rates for the same electricity will never see the same bill. Insulation, hot water habits and where you set the thermostat all feed into the total too, which is why one household raves about their running costs while the neighbour down the road, with what looks like the same house and the same brand of pump, grumbles about theirs. None of this is about who supplied or fitted the pump. It's about the tariff you're on, the fabric of the building, and whether the installer took the time to commission it properly rather than defaulting to settings that make the boiler swap easy but the bills higher.
How to pay less
- Switch to a time-of-use or dedicated heat pump electricity tariff so you buy your units when they're cheapest rather than paying a flat rate all day.
- Insulate before you install. Loft and cavity wall work cuts the heat demand the pump has to meet all winter, which lowers every bill that follows.
- Ask the installer to commission the system at the lowest flow temperature your radiators can cope with. A few degrees here makes a real difference to what you pay.
- Get three quotes and check each one has done a proper room-by-room heat loss survey rather than eyeballing it. A sloppy survey now means an oversized bill later.
- If your radiators are undersized for a lower flow temperature, price up replacing the worst offenders rather than accepting a higher flow temperature for the whole house.
- Keep an eye on your hot water settings and cylinder schedule. Heating water more often than you need to adds up over a year even if the space heating is efficient.
Common questions
Is an air source heat pump cheaper to run than a gas boiler?
It can be, but it isn't automatic. A well set up pump in an insulated home on a smart tariff often undercuts gas, while a poorly commissioned one on a standard tariff can cost more. The real prices below show the spread, and the deciding factors are your tariff, your insulation and the flow temperature the installer sets.
Do heat pumps still work in the middle of winter?
Yes. Air source heat pumps pull heat from the outside air even below freezing, they just work a little harder on the coldest days, which nudges the running cost up briefly. A correctly sized unit will keep the house warm through a normal British winter without needing backup heating.
Does the £7,500 grant help with running costs?
No. The Boiler Upgrade Scheme grant only reduces the upfront installation cost of an air source heat pump. Lower running costs come from your tariff, your insulation and a system that's been commissioned to run efficiently, none of which the grant touches.
What electricity tariff should I be on with a heat pump?
Look for a time-of-use or dedicated heat pump tariff rather than staying on a standard variable rate. These give you a cheaper overnight or off-peak window, and a heat pump can shift some of its heating and hot water into those cheaper hours if it's set up right. Ask your installer or supplier which tariffs are compatible with your system before you commit.
Will spending on insulation actually cut my heat pump running costs?
Generally yes, because a heat pump has to run longer or hotter to make up for heat leaking out through an uninsulated loft or cavity wall. Cutting the heat demand first means the pump can run at a lower, cheaper flow temperature to do the same job. It's worth pricing insulation work alongside the heat pump quote rather than treating them as separate decisions.
Why do two similar houses on the same street end up with such different heat pump bills?
It's almost never the pump itself. The usual culprits are the electricity tariff each household is on, how well insulated the house actually is compared with how it looks from outside, and whether the installer commissioned the system at a sensible flow temperature. Ask to see the commissioning settings if you want to understand why your bill looks different from a neighbour's.