1 Your property's heat demand
Estimated annual heat demand in kWh, or enter your own below
If you know your gas usage, your heat demand is roughly gas kWh × 0.85 (boiler efficiency). Average UK home: ~12,000 kWh.
2 Energy prices
Ofgem Q3 2026 cap: ~7.33p/kWh
pence per kWh
Ofgem Q3 2026 cap: ~26.11p/kWh
pence per kWh
pence per day
pence per day
3 System efficiency
New: 90-92%. Older: 75-85%.
Typical ASHP: 2.8-3.5. GSHP: 3.5-4.5.
Annual Heating Cost Comparison
Based on your inputs with current energy prices
Gas Boiler
£0
Fuel cost£0
Gas standing charge£0
Boiler service£80
Total£0
vs
️
Heat Pump
£0
Electricity cost£0
Standing charge saving£0
Annual service£150
Total£0
10-Year Cumulative Cost Comparison (no inflation)
| Year | Gas Boiler (cumulative) | Heat Pump (cumulative) | Difference |
|---|
What if energy prices change?
This table shows annual heat pump running costs at different electricity rates and COP levels. Your current selection is highlighted.
| COP \ Elec rate |
|---|
Assumptions and limitations
- Gas boiler cost includes fuel, gas standing charge, and annual service (£80).
- Heat pump cost includes electricity for heating, and annual service (£150). Does not include the additional electricity standing charge as most homes already have an electricity supply.
- If you switch fully from gas to a heat pump and disconnect gas, you save the gas standing charge (£115/year at current rates). This is included in the heat pump total.
- No hot water adjustment, both systems heat water as part of the heat demand figure.
- 10-year projection uses no inflation. Real costs may diverge as gas and electricity prices move at different rates.
- COP (Coefficient of Performance) represents seasonal average. Actual COP varies with outdoor temperature and system design.
Sources and review
Energy price defaults: Ofgem Q3 2026 price cap announcement (May 2026), ofgem.gov.uk
COP reference ranges: Energy Saving Trust heat pump data and MCS installer guidance
Boiler service cost: Industry average from multiple installer surveys
Reviewed by BetterHomeEnergy Research Team, April 2026. Editorial policy →
COP reference ranges: Energy Saving Trust heat pump data and MCS installer guidance
Boiler service cost: Industry average from multiple installer surveys
Reviewed by BetterHomeEnergy Research Team, April 2026. Editorial policy →
Cut running costs on either system: a smart thermostat plus smart TRVs let you heat only occupied rooms.
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