Installing an air source heat pump in the UK typically costs £7,000 to £13,000 supplied and fitted for an average three or four-bedroom home, before the £7,500 Boiler Upgrade Scheme grant is deducted; ground source systems run £15,000 to £35,000 because of the groundworks involved. Those headline figures move a lot depending on your property, your existing heating system, and what your installer finds during a survey, so here’s exactly what makes up the bill, and where the extra costs tend to hide.
What exactly are you paying for in a heat pump installation?
A heat pump quote is never just “the heat pump”. The unit itself is often the smaller line item once you add labour, and on an older or unmodernised property the supporting work can end up costing as much as the heat pump does. Here’s the full list of components that make up a typical installation:
- The heat pump unit: the outdoor unit (and indoor unit, on some systems) itself, sized to your property’s heat loss
- Installation labour: commissioning, connecting to your heating circuit, and getting the system running correctly, usually two to four days’ work
- Hot water cylinder: if you’re replacing a combi boiler, you’ll need a cylinder for the first time, as heat pumps don’t produce hot water on demand the way a combi does
- Radiator upgrades: heat pumps run at lower flow temperatures than gas boilers, so existing radiators are often undersized and need replacing with larger ones, or supplementing with underfloor heating in places
- Pipework: new or upgraded pipework to and from the outdoor unit, and sometimes wider bore pipework around the house to carry the increased water volume at lower temperatures
- Electrical work: a new dedicated circuit is standard, and on older consumer units you may need a supply upgrade to handle the additional load
- Controls and thermostat: a heat pump-compatible thermostat and weather compensation controls, which are more involved than a standard boiler timer
- Groundworks or boreholes: ground source only: either horizontal trenches across a large garden or vertical boreholes drilled to depth, which is the single biggest cost driver for GSHP
- Scaffolding: occasionally needed if the outdoor unit location or pipe routing requires access at height
- Removal of the old system: decommissioning and disposing of the old boiler and, where applicable, capping off the redundant gas supply
An MCS-certified installer prices most of this after a proper heat loss survey, not a desktop estimate, which is why quotes vary so much before a surveyor has actually visited.
How much does a heat pump cost by property type?
Expect roughly £6,500–£9,500 for a 1–2 bed flat, £7,000–£11,000 for a 3-bed semi, £9,500–£14,000 for a 4-bed detached home, and £13,000–£18,000+ for a large or older solid-wall property. These are indicative pre-survey ranges for a straightforward air-to-water ASHP installation, before the Boiler Upgrade Scheme grant. Your actual price depends on insulation levels, existing radiators, pipe runs, and electrical capacity, not just floor area.
| Property type | Typical supply & install cost | Notes |
|---|---|---|
| 1–2 bed flat | £6,500 – £9,500 | Lower heat loss, but outdoor unit siting and shared pipework routes can add complexity in flats |
| 3-bed semi-detached | £7,000 – £11,000 | The most common installation profile; usually needs some radiator upgrades |
| 4-bed detached | £9,500 – £14,000 | Higher heat loss and longer pipe runs; often needs a larger cylinder too |
| Large or older/solid-wall property | £13,000 – £18,000+ | Poor existing insulation usually means more extensive radiator and, sometimes, fabric upgrades to hit efficient flow temperatures |
How much do air-to-water and ground source heat pumps cost before and after the grant?
After the grant, air-to-water systems typically land at roughly £0–£10,500 and ground source systems at £6,000–£27,500, depending on property size and loop type, because the Boiler Upgrade Scheme grant is normally deducted from your quote upfront by the installer rather than paid to you separately, so the “after grant” price below is what you’d actually be asked to pay. The enhanced £9,000 rate applies to off-gas-grid homes replacing oil or LPG between 21 July 2026 and 31 March 2027; everyone else gets the standard £7,500.
| System type | Typical cost before grant | After £7,500 standard grant | After £9,000 enhanced grant (off-gas-grid) |
|---|---|---|---|
| Air-to-water ASHP (average home) | £7,000 – £13,000 | Roughly £0 – £5,500 | Roughly £0 – £4,000 |
| Air-to-water ASHP (large/complex property) | £13,000 – £18,000+ | £5,500 – £10,500+ | £4,000 – £9,000+ |
| Ground source (horizontal loop) | £15,000 – £25,000 | £7,500 – £17,500 | £6,000 – £16,000 |
| Ground source (borehole) | £20,000 – £35,000 | £12,500 – £27,500 | £11,000 – £26,000 |
Ground source systems are more expensive to install but generally run at slightly better efficiency than air source, since ground temperatures stay more stable through the year than air temperature. Whether the extra install cost is worth it usually comes down to whether you’ve got the garden space for a horizontal loop without the expense of drilling.
How much do air-to-air heat pumps cost, and do they qualify for the grant?
Air-to-air heat pumps (essentially reversible units similar to air conditioning, distributing warm air rather than heating water and radiators) cost considerably less to install than a wet system, typically £2,000 to £4,000, and since 21 July 2026 they qualify for a £2,500 Boiler Upgrade Scheme grant, but only when they fully replace an existing fossil fuel heating system rather than supplementing it. They’re not a like-for-like replacement for a wet central heating system in most UK homes, and are more commonly fitted as a supplementary heat source for an extension, garden room, or a property that doesn’t have wet radiators to begin with.
What costs do people forget to budget for with a heat pump?
The costs people most often forget are radiator upgrades, a hot water cylinder, an electrical or consumer unit upgrade, old system removal, and extra pipework or insulation. Almost every heat pump horror story about costs “spiralling” traces back to one of these being missed at quote stage rather than unforeseen:
| Often-missed cost | Typical extra | Why it gets missed |
|---|---|---|
| Radiator upgrades | £150 – £400 per radiator, several rooms | Assumed existing radiators will simply work; often they’re undersized for lower flow temperatures |
| Hot water cylinder | £1,200 – £2,500 installed | Combi boiler households often don’t realise they need one at all |
| Electrical/consumer unit upgrade | £300 – £1,200 | Older properties with dated consumer units may need capacity increased before the new circuit can be added |
| Old system removal and flue capping | £150 – £500 | Sometimes quoted as “excluded” in cheaper quotes |
| Additional pipework/insulation | £200 – £800 | Pipe runs longer than a standard boiler swap, plus insulation to meet MCS standards |
None of these are unusual or a sign something’s gone wrong. They’re simply part of doing the job properly. The issue is quotes that leave them out to look competitive on paper, only for them to appear as “extras” once work is underway. A proper survey should flag all of these before you sign anything.
How do 0% VAT and the grant combine to cut the real cost of a heat pump?
Together, 0% VAT and the Boiler Upgrade Scheme grant can turn a £10,000 pre-relief job into £2,500 or less out of pocket. These are two separate savings that stack on top of each other. Heat pump supply and installation, materials and labour, currently qualifies for 0% VAT, compared with the 20% VAT that applies to many other home improvement works. On a £10,000 installation, that’s roughly £2,000 you’re not paying that you would be on a like-for-like extension or renovation project. Layer the £7,500 (or £9,000 enhanced) Boiler Upgrade Scheme grant on top of that VAT-free price, and a £10,000 pre-VAT-relief job can realistically land at £2,500 or less out of pocket. The grant is deducted by your installer at the point of quoting, so you never need to apply for it yourself or wait for reimbursement. It should simply appear as a deduction on your final invoice.
Can you finance a heat pump instead of paying upfront?
Yes, it’s increasingly common for heat pump installers to offer finance options, either through their own arrangement with a lender or via green home improvement loan products aimed specifically at low-carbon heating, for anyone who doesn’t want to pay the balance upfront even with the grant applied. Terms and rates vary by lender and by your credit profile, so it’s not something we’ll put numbers on here, but it’s worth asking any installer you’re getting quotes from whether financing is available and what it would do to the total cost over the loan term. Spreading the cost can make sense if it lets you install now rather than staying on an ageing boiler for another few years while you save.
Is a heat pump worth the cost over the long term?
For most households, yes, over a 10 to 20-year ownership period. Install cost is only half the sum: a heat pump’s running costs depend on its efficiency, measured as Coefficient of Performance (COP), typically 2.5 to 4.0 depending on conditions, with a seasonal average (SCOP) of 3.5 or higher considered good. In practical terms, a well-installed heat pump with a healthy SCOP produces two-and-a-half to four units of heat for every unit of electricity it consumes, which is where the running-cost advantage over direct electric heating comes from. How it compares to a gas boiler on pure running costs depends heavily on the gap between electricity and gas unit prices at any given time, plus how well your home retains heat. A property with poor insulation and undersized radiators will see a smaller advantage than one that’s been set up properly.
Where the case is more clear-cut is over a longer horizon. Heat pumps typically last 15 to 20+ years with far fewer moving parts to fail than a gas boiler, gas prices have historically been volatile in a way that electricity-generation costs are increasingly decoupled from, and a fossil-fuel boiler is not a like-for-like alternative for a home that also wants solar generation or battery storage feeding into its heating. Over a 10 to 20-year ownership period, most households find the higher upfront cost is offset by some combination of lower running costs, avoided boiler replacement cycles, and, for many, a home that’s simply more comfortable to heat, with more consistent temperatures than the on/off blast of a combi boiler.
What should you ask for in a heat pump quote?
Ask for a heat loss calculation, an itemised cost breakdown, a list of exclusions, confirmation of the grant amount, the proposed flow temperature and SCOP, and proof of MCS certification. The single biggest driver of cost surprises is an incomplete quote, not a badly priced one. Before accepting any installer’s figure, make sure you have:
- An MCS heat loss calculation for the property, room by room. This is what the heat pump size, and therefore the grant eligibility and price, is actually based on. A quote given without one is a guess.
- An itemised breakdown covering the unit, labour, cylinder (if needed), radiator changes, electrical work, and controls as separate line items, not a single lump sum.
- A clear list of exclusions: what isn’t included, such as scaffolding, additional groundworks, or making good after pipework is run through walls and floors.
- Confirmation of the grant amount being applied and whether it’s the standard £7,500 or the off-gas-grid enhanced £9,000 rate, and that it’s shown as a deduction on the final price.
- The proposed flow temperature and expected SCOP for your system, so you have a benchmark to check performance against once it’s running.
- MCS certification for the installer. Required for Boiler Upgrade Scheme eligibility and a reasonable proxy for installation quality more broadly.
Get two or three quotes built on the same heat loss survey basis and they become comparable, rather than a guessing game over which installer has quietly left something out.
