Heat Pump Quotes UK 2026: Costs, Grants & What to Check
Air source heat pump installation costs £8,000-£18,000 before the £7,500 BUS grant. Here's what your quote should include and what to watch out for.
In short: An air source heat pump (ASHP) costs £8,000–£18,000 to install before the £7,500 BUS grant. That means you'll pay £500–£10,500 out of pocket, depending on the system size, your existing pipework, and whether your radiators need upgrading. It's a significant investment - and the quotes vary enormously because installers include (or exclude) very different things. Here's what to look for.
Quick cost summary
Air source heat pumps (ASHP)
| Property size | System output | Installed cost (before grant) | After BUS grant |
|---|---|---|---|
| 1–2 bed flat/terrace | 5–7 kW | £8,000–£11,000 | £500–£3,500 |
| 3 bed semi | 8–10 kW | £10,000–£14,000 | £2,500–£6,500 |
| 4 bed detached | 10–14 kW | £12,000–£16,000 | £4,500–£8,500 |
| 5+ bed / poorly insulated | 14–18 kW | £15,000–£18,000+ | £7,500–£10,500+ |
Ground source heat pumps (GSHP)
| Property size | System output | Installed cost (before grant) | After BUS grant |
|---|---|---|---|
| 3 bed semi | 8–10 kW | £20,000–£28,000 | £15,000–£23,000 |
| 4 bed detached | 10–14 kW | £25,000–£35,000 | £20,000–£30,000 |
| 5+ bed | 14–18 kW | £30,000–£45,000+ | £25,000–£40,000+ |
Ground source heat pumps are significantly more expensive because of the borehole drilling or ground loop trenching. They're more efficient (COP of 4.0–4.5 vs 3.0–3.5 for ASHP) but the payback period is much longer. For most homes, an air source heat pump is the practical choice.
Costs based on MCS installer data and MyBuildAlly quote analysis, Q1 2026.
What the BUS grant covers
The Boiler Upgrade Scheme (BUS) provides:
- £7,500 towards an air source heat pump
- £5,000 towards a ground source heat pump
Key eligibility requirements:
- Your property must be in England or Wales (Scotland has separate schemes)
- The property must have an existing heating system being replaced (not new builds)
- You must have a valid EPC (Energy Performance Certificate) - no EPC, no grant
- The installer must be MCS certified - this is non-negotiable
- The property must have adequate insulation - loft insulation to at least 200mm, cavity wall insulation where applicable. If you don't have these, you'll need to install them first
The grant is applied as a discount by the installer - you don't pay the full amount and claim it back. Your installer handles the application through the MCS portal.
Important: The BUS grant is scheduled to run until 2028, but funding is allocated on a first-come, first-served basis. Once the annual budget is committed, no more vouchers are issued until the next financial year. As of early 2026, demand is high and allocations can fill up, so don't delay if you're planning to apply.
What your heat pump quote should include
A complete heat pump quote should itemise all of these:
The heat pump unit
- Make, model, and output - e.g., "Vaillant Arotherm Plus 10kW"
- Warranty - most major brands offer 5–7 years. Some offer 10 with registration
- Noise rating - in decibels at 1 metre. This matters for planning compliance and neighbourly relations. Under 42dB is generally fine; over 50dB may cause issues
Hot water cylinder
Most heat pumps need a larger hot water cylinder than a conventional boiler. Budget £800–£1,500 for the cylinder itself, plus installation. If your quote doesn't mention a cylinder and you currently have a combi boiler, ask - you'll almost certainly need one, and it needs space somewhere in the house.
| Cylinder size | Suitable for | Typical cost (supply) |
|---|---|---|
| 170–200 litres | 1–3 bed, 1 bathroom | £800–£1,000 |
| 250–300 litres | 3–4 bed, 2 bathrooms | £1,000–£1,400 |
| 300+ litres | 4+ bed, multiple bathrooms | £1,200–£1,800 |
Radiator upgrades
This is the big one that many quotes exclude. Heat pumps run at lower flow temperatures than gas boilers (typically 35–45°C vs 60–80°C). That means your existing radiators may not be large enough to heat the rooms adequately. In most homes built before 2000, at least some radiators will need upsizing.
Budget £150–£300 per radiator for supply and fitting. A 3-bed semi might need 4–8 radiators replaced - that's £600–£2,400 that's often missing from heat pump quotes.
If the quote says "existing radiators to be retained" without an assessment of whether they're adequate at low flow temperatures, that's a red flag.
Pipework modifications
Heat pumps use 22mm or 28mm pipework (larger than the 15mm microbore found in many older homes). If your existing pipework is undersized, sections will need replacing. This is disruptive and can add £1,000–£3,000 depending on how much needs doing.
Electrical supply
An air source heat pump needs a dedicated electrical supply - typically a 32A circuit from your consumer unit. If your consumer unit doesn't have a spare way or needs upgrading, that's an extra £300–£800 for a new board.
Ancillaries
- Buffer tank or low-loss header - some systems need one, others don't. £300–£600 if required
- System filter and inhibitor - £100–£200
- External unit base/plinth - concrete pad or anti-vibration mount. £100–£300
- Condensate drain - from the outdoor unit. Often overlooked
- System flush - cleaning the existing pipework before connecting the heat pump. £300–£500
MCS certification and commissioning
- MCS registration - confirms the installation meets quality standards and is required for the BUS grant. The installer must be MCS certified
- Commissioning - testing and setting up the system, including flow rates, temperatures, and controls
- Handover - showing you how to use the system, setting up the app/controls, explaining the maintenance schedule
BUS grant application
The installer should handle the BUS grant application as part of their service. If they're charging extra for it, or if they're not MCS certified and can't apply, reconsider.
What's often missing from quotes
Based on the heat pump quotes we've analysed, these are the most common exclusions:
- Radiator upgrades - the biggest gap. Quotes assume existing radiators will work, but they often won't at lower flow temperatures
- Hot water cylinder - especially if you're replacing a combi boiler. You currently don't have a cylinder; now you need one, plus somewhere to put it
- Pipework modifications - replacing undersized microbore pipework is expensive and disruptive
- Electrical supply upgrade - a new consumer unit or dedicated circuit
- Loft/cavity insulation - required for BUS grant eligibility but often treated as "your responsibility"
- Scaffolding - some installers need scaffolding for the refrigerant pipework routing. Check whether it's included
- Making good - repairing walls, floors, and decoration after pipework modifications. Rarely included
ASHP vs gas boiler: running costs
The running cost comparison depends on several factors, but here are realistic 2026 figures:
| Fuel | Unit cost (2026) | Efficiency | Cost per kWh of heat |
|---|---|---|---|
| Gas boiler (modern condensing) | 7.5p/kWh | 92% | 8.2p |
| ASHP (average COP 3.2) | 24.5p/kWh | 320% | 7.7p |
| ASHP (good COP 3.8) | 24.5p/kWh | 380% | 6.4p |
| GSHP (average COP 4.0) | 24.5p/kWh | 400% | 6.1p |
| Oil boiler | 65p/litre (≈6.5p/kWh) | 90% | 7.2p |
At current energy prices, an air source heat pump is roughly comparable to gas on running costs - slightly cheaper if the system is well designed and the house is reasonably insulated, slightly more expensive if not. The financial case improves as gas prices rise relative to electricity, and you also benefit from lower carbon emissions.
The big savings come if you're replacing oil, LPG, or electric storage heaters - heat pumps cut running costs by 30–50% in these scenarios.
Energy prices based on Ofgem price cap and domestic energy tariff averages, Q1 2026.
How to find an MCS-certified installer
MCS certification is non-negotiable if you want the BUS grant. Use the MCS Find an Installer directory to find certified installers in your area.
When comparing installers:
- Check their MCS scope - make sure they're certified for heat pumps specifically, not just solar
- Ask for references - speak to previous customers, ideally those with a similar property type
- Get at least three quotes - heat pump pricing varies more than almost any other home improvement
- Check the heat loss calculation - a proper installer will do a room-by-room heat loss calculation (not just a rough estimate based on floor area). This determines the correct heat pump size. An oversized heat pump wastes money; an undersized one won't heat the house
- Ask about the design temperature - the system should be designed to maintain 21°C indoors when the outdoor temperature is –3°C (the UK design condition). Some installers design to –1°C or 0°C, which means the system struggles in genuinely cold weather
Planning permission and noise
Most air source heat pumps fall under permitted development and don't need planning permission, provided:
- The unit is at least 1 metre from the property boundary
- The volume of the unit (including housing) doesn't exceed 0.6 cubic metres
- It's not on a pitched roof, a wall fronting a highway, or within the curtilage of a listed building
- Noise levels comply with MCS 020 - the noise assessment standard
If your property is in a conservation area or is listed, you'll likely need planning permission. Check with your local planning authority before committing.
Common mistakes to avoid
- Choosing based on price alone - the cheapest quote often excludes radiator upgrades, pipework modifications, or proper commissioning. Compare total installed costs including everything
- Not insulating first - a heat pump in a poorly insulated house works harder, costs more to run, and may need a larger (more expensive) unit. Insulate first, then size the heat pump to the improved house
- Ignoring the hot water cylinder - if you're replacing a combi boiler, you need space for a 200–300 litre cylinder. Plan where it's going before you commit
- Skipping the heat loss calculation - any installer who sizes a heat pump based on "number of bedrooms" rather than a proper room-by-room heat loss calculation isn't doing their job properly
- Forgetting maintenance - heat pumps need an annual service, typically £100–£200. Factor this into your ongoing costs. See our boiler replacement guide for how maintenance costs compare
What about your project?
Heat pump quotes are some of the most inconsistent we see - what's included in one installer's £12,000 quote might be missing from another's £9,000 quote, making the cheaper one actually more expensive once you add the extras. Upload your heat pump quote to MyBuildAlly and we'll check it against MCS standards, flag any missing items, and make sure the system has been properly sized for your property.
Sources
- Energy Saving Trust - Air Source Heat Pumps - independent guidance on heat pump technology and costs
- GOV.UK - Boiler Upgrade Scheme - BUS grant eligibility and application process
- MCS - Microgeneration Certification Scheme - installer directory and certification standards
- Ofgem - Energy Price Cap - current domestic energy tariff rates
- BCIS Average Building Prices - regional cost benchmarks, Q1 2026
- Analysis of heat pump installation quotes submitted to MyBuildAlly, January–March 2026