renewables
Air source heat pumps
An air source heat pump costs £7,000 to £13,000 installed before grant, and the Boiler Upgrade Scheme grant in England and Wales takes £7,500 off that for eligible properties. The grant is claimed by the installer, who must be MCS certified.
What this covers
What it costs. An air source heat pump costs £7,000 to £13,000 installed before grant. Full cost breakdown.
What the job covers
- Air source heat pump installation
- Heat loss surveys and emitter sizing
- Cylinder upgrades for heat pump coils
- Radiator upsizing for low flow temperatures
- Boiler Upgrade Scheme applications through MCS installers
What is involved
A heat pump moves heat rather than making it, taking energy from outside air and lifting it to a useful temperature. It produces three to four units of heat for each unit of electricity, but only if it is asked to deliver water at a low temperature. Ask it for 65 degrees and the efficiency collapses towards a direct electric heater. Everything about a good installation follows from that one fact.
Which means the survey is the job. A room by room heat loss calculation establishes what each space needs, and the emitters are then sized to deliver that at a flow temperature around 35 to 45 degrees. In practice several radiators usually need to be larger, and rooms with underfloor heating need nothing. An installer who quotes a heat pump without producing that calculation is selling an appliance rather than designing a system, and the householder finds out in the first cold week.
Hot water is separate. A heat pump cylinder needs a much larger coil than a boiler cylinder, so an existing cylinder is usually replaced. The cylinder also runs a weekly higher temperature cycle against legionella, generally using its immersion heater.
The installer must be MCS certified for the property to qualify for the Boiler Upgrade Scheme, and the grant is deducted from the quote rather than claimed back. Planning permission is usually not needed under permitted development in England, but there are conditions on siting and noise, and they are stricter in conservation areas, on listed buildings, and in Scotland, Wales and Northern Ireland.
Air source heat pump installation, one of the jobs a heat pumps specialist is hired for.
Choosing someone for the job
Ask for the room by room heat loss calculation and the design flow temperature in writing before signing anything. Ask which radiators are being changed and why. Confirm MCS certification and that the grant is deducted from the price. Ask what the unit's sound power level is and where it will sit relative to your own and your neighbour's windows.
Common questions
How much does a heat pump cost after the grant?
Typically £7,000 to £13,000 installed, less the £7,500 Boiler Upgrade Scheme grant in England and Wales, so many households pay between nothing and £5,500. Scotland runs its own funding through Home Energy Scotland.
Do I need new radiators?
Often some of them. A heat pump runs at a lower flow temperature, so radiators sized for 70 degree water may be too small at 45. The heat loss survey identifies which.