Can I get a grant for both?

Yes — the Boiler Upgrade Scheme gives £7,500 toward either an air or ground source heat pump.

Which is cheaper to run?

Ground source is slightly cheaper to run, but the higher install cost means air source usually pays back faster for typical homes.

Do I need underfloor heating?

Not strictly; well-sized radiators work, but underfloor or larger radiators improve comfort with either system.

Air Source vs Ground Source Heat Pumps

Both heat pumps move heat rather than burn fuel, but they suit different homes. Here is the plain-English comparison to help you choose.

Last reviewed: August 2026Sources: Boiler Upgrade Scheme (GOV.UK) · Energy Saving Trust

Upfront cost

Air source units typically cost £7,000 to £13,000 installed before the £7,500 Boiler Upgrade Scheme grant. Ground source costs more — usually £15,000 to £30,000 — because of the ground loop trenching or borehole.

Efficiency and performance

Ground source is marginally more efficient and steadier year-round, especially in very cold spells. Air source is more than efficient enough for most UK homes and easier to retrofit.

Space and disruption

Air source needs only an outdoor unit on a wall or the ground; ground source needs significant garden space for trenches or a borehole, which adds time and cost.

Which should you choose

Pick air source for most retrofits and smaller gardens; pick ground source if you have land, want maximum efficiency, or plan a large new-build.

FAQs

Can I get a grant for both?: Yes — the Boiler Upgrade Scheme gives £7,500 toward either an air or ground source heat pump.
Which is cheaper to run?: Ground source is slightly cheaper to run, but the higher install cost means air source usually pays back faster for typical homes.
Do I need underfloor heating?: Not strictly; well-sized radiators work, but underfloor or larger radiators improve comfort with either system.