Boilers in the UK: ECO4, the heat pump switch and new boiler options

What boiler grants are available in 2026?

Two schemes. ECO4 funds a full boiler replacement at zero cost if your household receives qualifying benefits and your home is rated EPC D or below. The Boiler Upgrade Scheme (BUS) gives every eligible homeowner £7,500 off an air-source heat pump or £5,000 off a ground-source one, and isn't means-tested.

You can't stack them. ECO4 replaces a boiler with another boiler. BUS replaces a fossil-fuel system with a heat pump. Pick the route that fits the home. Our full ECO4 eligibility guide walks through the benefits list, the EPC requirement and the typical timeline (eight to twelve weeks from application to install).

About a third of UK households meet the ECO4 income criteria, which makes it always worth a check. The BUS grant runs until March 2028 and ECO4 closes in December 2026, so the planning horizon for both is short.

When does switching to a heat pump make sense over a new boiler?

When your home is EPC C or above, you've insulated, and you've got outdoor space. The £7,500 grant brings the gap to within £2,500 of a new combi for a well-set-up three-bed semi.

The honest version is more conditional. A heat pump in a poorly insulated solid-wall terrace will cost more to run than a modern gas combi, because the pump has to work harder to hit the same flow temperature. Get the loft, walls and draught-proofing sorted first, then revisit. Our heat pumps hub covers the sizing, the running-cost maths and the install steps in more depth.

What does a new boiler actually cost in 2026?

£2,000 to £4,500 for a gas combi fully installed, according to the Energy Saving Trust. A system boiler with a hot water cylinder runs £4,000 to £6,500. The brand (Worcester Bosch, Vaillant, Ideal), location and the amount of pipework that needs moving drive the spread.

Heat pumps sit in a different bracket. Air-source costs £7,000 to £16,000 before the £7,500 BUS grant, which puts net cost at £0 to £8,500 for most homes. Ground-source runs £15,000 to £35,000 before the £5,000 grant. See our new boiler cost guide for the full breakdown by type and property size.

Which boiler type suits your home?

Combi for flats and small homes with one bathroom; system boiler for larger homes with multiple bathrooms; regular (heat-only) for properties that already have an open-vented system; biomass for off-grid homes where gas isn't available.

Heat pumps are the long-term decarbonisation route and the only one the government is actively subsidising. The grant maths assumes most UK homes will move that way over the next decade, which is why ECO4 is winding down and BUS is the headline scheme. Our biomass boiler guide covers the off-grid case in detail.

What do landlords need to know about boilers and MEES?

Landlords aren't required to upgrade boilers under MEES, but the 2030 band C rule may force the issue. From April 2028, new tenancies in England and Wales need to hit band C; from April 2030, every existing tenancy follows. Fines for letting a non-compliant property run up to £30,000 per breach.

For most D-rated rentals, insulation does the heavy lifting on getting to band C. But where insulation alone isn't enough, swapping a non-condensing boiler for a modern condensing combi (or a heat pump with the BUS grant) often closes the gap. The EPC for landlords sub-hub walks through the timeline, the £15,000 cost cap and the registered exemption routes.