The £7,500 Boiler Upgrade Scheme (BUS) grant
Under the UK Government Boiler Upgrade Scheme (BUS), property owners in England and Wales are eligible for a non-repayable £7,500 grant towards the purchase and installation of an air source or ground source heat pump.
The grant is applied directly by your MCS-certified installer, deducting £7,500 off the upfront invoice total. To qualify, your home must have a valid Energy Performance Certificate (EPC) with no outstanding recommendations for loft or cavity wall insulation.
Air Source vs Ground Source heat pump economics
Air source heat pumps (ASHP) are the most popular retrofit solution in the UK, typically costing £9,000 to £14,000 before the grant (leaving a net homeowner cost of just £1,500 to £6,500). They absorb ambient heat from outside air even in temperatures as low as -15°C.
Ground source heat pumps (GSHP) are more efficient but require extensive outdoor garden excavation for horizontal trenches or deep vertical boreholes, costing £18,000 to £35,000 before the £7,500 grant.
Worked example: 3-4 bedroom semi-detached home with ASHP
Installing an 8kW air source heat pump in a 3-bedroom semi-detached house, including a new hot water cylinder and upgrading 3 radiators to larger low-temperature units.
Gross installation cost is £11,500. Deducting the £7,500 Boiler Upgrade Scheme grant leaves a net out-of-pocket cost of £4,000, comparable to the cost of a premium gas boiler replacement. Pairing the system with a dynamic off-peak electricity tariff (such as Octopus Agile or Cosy) yields estimated annual heating bill savings of £250 to £450 compared to an old gas boiler.
Inputs for the heat pump cost calculator
Heat pump technology
Air source (ASHP) or ground source (GSHP).
Home size / heating demand
Small home (1-2 beds, ~5kW), medium home (3-4 beds, ~8-10kW), or large home (5+ beds, ~12-16kW).
Radiator upgrades
Allowance for replacing undersized radiators with larger double-panel units for low-temperature heat distribution.
Hot water cylinder
Inclusion of a heat-pump-compatible unvented hot water cylinder with large internal heat exchanger coil.
Boiler Upgrade Scheme (£7,500 grant)
Toggle eligibility for the £7,500 Government grant (England & Wales).
CALCULATOR QUESTIONS
UK heat pump cost calculator (£7,500 grant) questions
Who is eligible for the £7,500 Boiler Upgrade Scheme grant?
Homeowners and small business owners in England and Wales replacing an existing fossil fuel heating system (gas, oil, or direct electric) with an MCS-certified heat pump.
Do heat pumps work in freezing UK winters?
Yes. Modern air source heat pumps operate efficiently down to -15°C or even -20°C, extracting thermal energy from cold ambient air using compressed refrigerants.
Do I need to replace all my radiators for a heat pump?
Not necessarily. Most homes only need to upgrade 2 to 4 radiators in the coldest rooms to larger double-panel (Type 22) radiators to distribute comfortable heat at lower 45°C water flow temperatures.
Are heat pumps cheaper to run than a gas boiler in the UK?
With a high Seasonal Coefficient of Performance (SCOP of 3.2 to 4.0) and a smart time-of-use tariff (like Octopus Cosy or Agile), running a heat pump is cheaper or comparable to a modern condensing gas boiler.
Do heat pumps require planning permission in England?
Most air source heat pumps are classed as Permitted Development in England provided they comply with MCS noise standards (MCS 020) and are situated at least 1 metre from property boundaries.