Air source heat pumps under ECO4: questions UK households often ask (guide 2026)

Guide by ApplyFreeBoiler.uk (Reliant Energy Solutions Ltd), a heating and insulation installer in Bury, Greater Manchester. We are not the government, Ofgem or an energy supplier.

An air source heat pump can be one of the heating options offered through ECO4, usually where a home's insulation and layout suit it. Households often have the same handful of questions before a survey. This guide answers them in general terms. It is information from ApplyFreeBoiler.uk, a heating and insulation installer in Bury. Your surveyor and installer will explain what applies to your home. This page does not guarantee funding.

1. How it heats the home

A heat pump moves heat from the outside air into your heating water. It works best running steadily at a lower temperature than many older boilers, rather than in short hot bursts.

2. Why insulation is checked first

Because it runs at lower water temperatures, a heat pump suits homes that hold their heat. The survey usually looks at loft and wall insulation before a heat pump is designed.

3. Where the outdoor unit goes

The outdoor unit needs space for air to move around it and a solid base. The installer will talk through the position, the distance from boundaries and any planning points.

4. Radiators may change

Some radiators may need to be larger so rooms stay warm at the lower water temperature. A room-by-room heat loss calculation decides this.

5. Hot water cylinder

Most heat pump systems store hot water in a cylinder, so space for one, often in an airing cupboard, is part of the survey.

6. Living with it day to day

Radiators may feel warm rather than hot, and the system is often left on for longer periods. Ask your installer to show you the controls and settings before they leave.

7. Check funding and local figures

See ECO measures by council on ApplyFreeBoiler.uk, built from DESNZ Household Energy Efficiency statistics, to see how many ECO measures have been installed in your local authority area. Use the ApplyFreeBoiler.uk eligibility check to see whether an ECO4 heating or insulation pathway may be available for your home in England, Scotland or Wales. ECO4 is due to close on 31 December 2026.