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 on this page are drawn from three-bed installs, so you can see where the money actually goes before you commit to a quote.
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, not just the box on the wall outside.
- The £7,500 Boiler Upgrade Scheme grant is usually taken off the price by an accredited installer, so you pay the reduced figure rather than claiming it back yourself.
- 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 and stops you being oversold.
- Two quotes for the same house can differ sharply once you factor in whether radiators need upsizing, whether a cylinder needs finding a home, and who is doing the pricing.
- Homes without an existing hot water cylinder cost more to convert, since space has to be found and plumbed in from scratch.
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 for what looks like the same job. 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 and decent loft insulation. If your existing radiators are too small for the lower flow temperatures a heat pump likes, several will need upsizing, and each swap adds labour and materials on top of the unit cost. The cylinder is another variable, since homes without one need space found and plumbed in, while homes that already have a suitable cylinder save that cost outright. Pipework runs, the distance from the outdoor unit to the plant room, electrical upgrades and even scaffolding for awkward access all move the number too. Who owns the firm doing the work matters as much as the house itself. National franchise-style installers tend to quote above local, independent heating engineers for the same spec, partly because of overheads and partly because of how they price risk on a job they haven't scoped in person. Region plays a part as well, since labour rates and demand for installers differ across the country, and areas with fewer accredited firms tend to see less competitive pricing than areas with plenty of choice.
How to pay less
- Get three quotes from MCS accredited installers and make sure each has run a full heat loss calculation before pricing the job, not after.
- Check the £7,500 grant has been deducted on the quote rather than left for you to claim later, and get that confirmed in writing.
- Ask whether your current radiators can be kept, as fewer swaps means a lower labour bill and less disruption.
- Get quotes from both local heating engineers and larger national firms for the same spec, since the price for identical work can vary by who is doing the quoting.
- Pay any deposit by credit card so Section 75 protection covers you if the firm folds before finishing.
- Ask what happens to the old boiler and any asbestos-era pipework during removal, since unexpected extra work is where quotes creep upward after the fact.
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, so bigger is not automatically better.
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 as they are. The heat loss survey tells you exactly which rooms need attention, so ask to see that breakdown before you agree a price.
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 in writing, so you are comparing quotes on the same basis and not one that still has the grant to come off.
Why is one quote so much higher than another for the same house?
The biggest gaps usually come down to how many radiators are being upsized, whether a cylinder needs to be found space for, and whether the firm is a national outfit or a local independent. Ask each installer for an itemised breakdown rather than one lump sum, so you can see exactly what is driving the difference.
Does a heat pump cost more to run than a gas boiler?
Running costs depend on your electricity and gas prices, your home's insulation and how well the system is set up, and that is a separate question from installation cost. The prices on this page cover the install itself, not ongoing running costs, so treat the two as different decisions.
What should be included in a heat pump quote?
A firm quote should cover the outdoor unit, any indoor unit or controls, the cylinder if you need one, radiator changes, pipework, electrical work and the grant deduction, all itemised rather than bundled into one figure. If a quote is missing the heat loss survey behind it, treat that as a reason to ask more questions before signing.