The Spring Statement of 23rd March 2022 has reversed the 2019 ruling as from 1st April 2022, meaning that the social conditions and 60% requirements no longer apply. This has been implemented to encourage homeowners to install energy saving heating materials.
The zero rating applies to installations only and therefore cannot be applied to sellers of equipment only.
This applies to installations of Air Source Heat Pumps and also includes Air Conditioning systems if they can be used to heat the home.
In Summary, providing that the heat pump uses air as the heat source to heat the home it will qualify as an energy saving material and be zero rated for VAT, irrespective of whether it can also cool or not. The heat pump needs to be permanently fixed and not portable.