Compare ASHP running costs to your current gas, oil, LPG or electric heating. Includes the £7,500 Boiler Upgrade Scheme grant and tells you the realistic payback period.
Current heating cost
With ASHP
Get a full retrofit assessment
A heat pump only saves money if your house is ready for one. Our assessment looks at insulation, ventilation, radiator sizing and electrical supply — making sure the heat pump is the right next step (or telling you what to do first).
Book a free retrofit assessment →How is this calculated?
Heat demand is estimated from house type and insulation level using typical UK figures:
- Detached: 18,000–28,000 kWh/year for heating
- Semi-detached: 12,000–18,000 kWh/year
- Mid-terrace: 9,000–14,000 kWh/year
- Flat: 6,000–9,000 kWh/year
Fuel rates used: Gas 7p/kWh; Oil 8p/kWh (price varies); LPG 13p/kWh; Electric 28p/kWh standard; Heat-pump tariff blended rate ~16p/kWh.
Boiler efficiency: Gas/oil/LPG modelled at 85% efficiency. Electric storage at 100%.
ASHP performance: Coefficient of Performance (COP) varies by insulation: poor 2.5, OK 3.0, well-insulated 3.5. A COP of 3 means 1 kWh of electricity produces 3 kWh of heat.
Install cost: Typical full install £11,000–£14,000 (modelled at £12,500). Minus £7,500 BUS grant = ~£5,000 net.
CO₂: Gas 0.183 kg/kWh, oil 0.247, LPG 0.214, electricity 0.207 (BEIS 2024). UK grid intensity falling — long-term ASHP CO₂ savings will increase.
Real performance depends heavily on installation quality, refrigerant choice, controls and how the house was prepared. Fabric-first (insulation before heat pump) is almost always the right order.