Air source heat pump costs after the grant

The honest headline

A properly specified air source heat pump installation in 2026 costs between £8,000 and £16,000 before support for the large majority of UK homes, with £11,000–£14,000 the crowded middle of the market. Subtract the £7,500 Boiler Upgrade Scheme grant — deducted from the quote upfront, with 0% VAT until 31 March 2027 — and most households pay £3,500 to £8,500. That range is wide because houses are: a modern, well-insulated semi with recent radiators sits at the bottom, a draughty four-bed Victorian needing emitter upgrades sits at the top.

What you'll pay, by house type

• Two-bed terrace or modern flat with outdoor space — 5–7 kW unit, minimal radiator work. Installed £9,000–£11,500; after grant £1,500–£4,000.
• Three-bed semi (the UK default) — 8–10 kW unit, cylinder added, three or four radiators upsized. Installed £11,500–£14,000; after grant £4,000–£6,500.
• Four-bed detached — 10–14 kW unit, cylinder, more substantial emitter work. Installed £13,000–£16,000; after grant £5,500–£8,500.
• Large or solid-wall period home — 14–16 kW or high-temperature unit, significant radiator replacement. Installed £15,000–£20,000+; after grant £7,500–£12,500+.

For context, a like-for-like gas boiler replacement with a cylinder and some radiator work runs £3,000–£5,500 in 2026. The grant has pushed the standard semi-detached heat pump into the same financial conversation — which is precisely what it was designed to do.

What a complete quote must include

The unit itself is only 40–50% of the job. A quote you can trust itemises: the outdoor unit and its base or brackets; a hot water cylinder (most boiler-replacing installs need one — £800–£1,500 installed, and finding it a home in an airing cupboard or loft is part of the design); radiator upgrades where the room-by-room heat loss calculation demands them (£150–£350 per radiator); system flushing, new controls, and any pipework upsizing; commissioning, MCS registration, and the DNO notification for the electrical connection. If a quote is silent on the heat loss calculation, it is not a design — it is a guess wearing one.

How to keep the number at the low end

Three legitimate levers. Compare two or three MCS quotes — the spread on identical houses regularly hits £2,000, and the installer guide covers how to compare like for like. Time the work outside the autumn rush, when diaries are loose and pricing keener. And ask each installer to model running costs at your actual tariff as part of the quote — it costs nothing, exposes lazy design at 55°C flow temperatures, and tells you which firm is engineering for efficiency rather than for a quick fit. What does not work: skipping the cylinder or radiator work to save capital. The running-costs page shows why an efficient install recovers those items inside a few winters.

Ground source instead?

If you have the land or the project scale for it, ground source delivers higher year-round efficiency for a higher upfront cost — the same £7,500 grant applies. The GSHP cost page runs those numbers, and the eligibility page confirms the conditions both technologies share.