DATA-BACKED GUIDE · UPDATED JULY 2026
Air source heat pump installation cost for a 3-bed house
A three-bed semi is the most common home in Britain, and it is also the one most people are pricing a heat pump for. The install bill covers far more than the outdoor unit, taking in a hot water cylinder, any radiator upgrades and the pipework to tie it all together. The real prices below are drawn from three-bed installs so you can see where the money actually goes before you commit.
The quick version
- The quote for a three-bed heat pump install bundles the unit, a hot water cylinder, controls and often some radiator swaps.
- The £7,500 Boiler Upgrade Scheme grant is usually taken off the price by an accredited installer, so you pay the reduced figure.
- Installation is an energy-saving measure, so it carries 0% VAT until 2027, unlike a standard gas boiler swap.
- A proper heat loss survey should come before any firm price, since it sets the size of unit and radiators you need.
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
Two three-bed houses can attract very different quotes. Age and insulation matter most, because a leaky Victorian terrace needs a bigger pump and more radiator work than a modern estate house with cavity walls. If your existing radiators are too small for the lower flow temperatures a pump likes, several will need upsizing, and each swap adds labour and materials. The cylinder is another variable, since homes without one need a place found for it. Pipework runs, the distance from the outdoor unit to the plant room, electrical upgrades and even scaffolding for awkward access all move the number. National firms tend to quote above local heating engineers for the same job, so the make-up of who you ask shapes the spread too.
How to pay less
- Get three quotes from MCS accredited installers and make sure each has run a full heat loss calculation.
- Check the £7,500 grant has been deducted on the quote rather than left for you to claim later.
- Ask whether your current radiators can be kept, as fewer swaps means a lower labour bill.
- Pay any deposit by credit card so Section 75 protection covers you if the firm folds before finishing.
Common questions
What size heat pump does a 3-bed house need?
It depends on heat loss, not floor area alone. A well insulated three-bed might need a smaller unit while an older draughty one needs more output. A proper survey sizes it correctly, and an oversized pump costs more to buy and runs less efficiently.
Do I need to replace all my radiators?
Not usually all of them. Heat pumps run cooler than boilers, so some radiators may need upsizing to give out the same warmth, but many can stay. The heat loss survey tells you exactly which rooms need attention.
Is the £7,500 grant taken off the quote automatically?
An MCS accredited installer normally claims the Boiler Upgrade Scheme grant on your behalf and shows the price after it is deducted. Always confirm this is the case so you are comparing quotes on the same basis.