How much does an air source heat pump cost installed in the UK in 2026?

An air source heat pump (ASHP) installed in the UK in 2026 typically costs £8,000 to £14,000 all-in including the outdoor unit, hot water cylinder, controls, MCS certification, and labour. The Boiler Upgrade Scheme (BUS) grant covers £7,500 of that, applied by the MCS installer at quote stage. Net household cost is typically £500 to £6,500 after the grant. Ground source heat pumps cost considerably more (£18,000 to £35,000 installed) and also qualify for the £7,500 BUS grant.

Should I switch to a heat pump or just replace my gas boiler?

Worth modelling, but rarely the right answer today unless your home is already well-insulated to EPC C or better and you have room for an outdoor unit. The cost-of-living calculus favours a like-for-like gas boiler replacement for most UK households in 2026. The climate / future-proofing calculus favours a heat pump because gas boilers will be banned in new-build properties from 2025 under the Future Homes Standard, and existing-home gas boiler installations may face restrictions later this decade. If you're not insulated yet, the order is: insulate first, then heat pump.

UK 2026 / June 2026

Gas boiler vs heat pump cost

Q: Is a heat pump cheaper to run than a gas boiler?

In a well-insulated home (EPC C or better) the running costs are typically comparable to a high-efficiency gas combi or 5-15% lower. In a poorly insulated home (EPC D or worse) heat pump running costs can be higher than gas, because the heat pump must run for more hours per day and electricity is around 4x the unit cost of gas. Heat pumps are ~300% efficient (COP 3.0 typical) vs ~93% for an A-rated combi, but that efficiency advantage is partly offset by the higher unit cost of electricity in the UK domestic energy market.

Upfront cost is the dominant variable today: a like-for-like gas boiler replacement costs £2,500-£4,500 installed. An air source heat pump costs £8,000-£14,000 installed before the £7,500 BUS grant, leaving a typical household net cost of £500-£6,500.

Side-by-side

	Like-for-like gas boiler	Air source heat pump
Upfront cost installed	£2,500 - £4,500	£8,000 - £14,000
Grant	None typically (ECO4 if eligible)	£7,500 BUS grant (England + Wales)
Net cost	£2,500 - £4,500	£500 - £6,500
Install time	1-2 days	3-5 days
Efficiency	~93% (A-rated condensing)	~300% (COP 3.0 typical)
Running cost (well-insulated home)	Comparable	Comparable or 5-15% lower
Running cost (poorly insulated)	Lower	Often higher
Outdoor unit needed	No	Yes (sized to property)
Hot water cylinder needed	Only for system/regular	Yes, always
EPC requirement	None	Ideally EPC C or better
MCS certified installer required	No (Gas Safe is the standard)	Yes (BUS grant requires MCS)
Future Homes Standard (England, from 24 March 2027)	Replacement in existing homes still allowed; new homes need low-carbon heating	Meets the low-carbon heating requirement

When a heat pump wins

EPC C or better, with cavity wall and loft insulation already done
Underfloor heating or oversized radiators (heat pumps run at lower flow temperatures)
Outdoor space for an external unit (typically 1m x 1m footprint plus 30cm clearance)
Owner-occupier with no plans to move within 5-7 years
Comfortable with a 4-6 week install lead time vs same-week boiler swap
Off-gas-grid properties (where the heat pump replaces an oil or LPG boiler with much higher running costs)

When a gas boiler swap wins

EPC D or worse, with insulation work not yet done
Older radiators sized for a high flow temperature (60-70 degC); replacing them adds £100-£300 per radiator
Small properties with no space for an outdoor unit
Cost-constrained replacement: ECO4 eligible households can get a free gas boiler in days
Tenant or short-term owner
Mains gas connection good and pressure strong

The Future Homes Standard context

The Future Homes and Buildings Standards were published on 24 March 2026 (Building Circular 01/2026) and come into force in England on 24 March 2027. They require low-carbon heating and on-site renewable electricity in new homes, which in practice rules out a gas boiler as the main heat source in a new build. They apply to new buildings, not to replacing a boiler in an existing home, and no date has been set for ending gas boiler replacements in existing homes. If you're replacing a gas boiler today and plan to stay another 15+ years, modelling the heat pump option is worth the effort.

FAQ

How much does an air source heat pump cost installed?

£8,000-£14,000 installed before the £7,500 BUS grant. Net household cost typically £500-£6,500.

Is a heat pump cheaper to run than a gas boiler?

Roughly comparable in a well-insulated home (EPC C+); often higher in a poorly insulated home (EPC D-G). Heat pump unit-running efficiency is ~3x gas boiler efficiency but electricity is ~4x the unit cost of gas.

What is the £7,500 BUS grant?

The Boiler Upgrade Scheme (gov.uk/apply-boiler-upgrade-scheme) provides £7,500 toward an air source or ground source heat pump installation in England or Wales. £5,000 for biomass boilers in rural off-grid properties. The MCS certified installer applies on the homeowner's behalf.

Should I insulate first or go straight to a heat pump?

Insulate first if you're below EPC C. Loft insulation and cavity wall insulation typically cost £200-£600 each and the payback on running costs (combined with future heat pump efficiency) is much better than going straight to a heat pump in a poorly insulated home.

Will I be forced to switch eventually?

Not under current published policy. The Future Homes Standard, in force in England from 24 March 2027, applies to new homes. Replacing a gas boiler in an existing home remains permitted, with no published end date.

Going gas? See cost by boiler type. Going heat pump? Start at the BUS grant guide and find an MCS certified installer at mcscertified.com. For deeper running-cost comparison see gasboilercost.com.