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Heat pump vs gas boiler: 5-year cost breakdown for UK homes
Published 25 April 2025
Is a heat pump actually cheaper than keeping your gas boiler over the next few years? Here is a full 5-year breakdown for a typical UK 3-bed semi.
The scenario
A 3-bed semi-detached home in England with average insulation, annual heat demand of 12,000 kWh.
Upfront costs
| Heat pump | New gas boiler | |
|---|---|---|
| Unit + installation | £10,000 | £2,500 |
| Less BUS grant | -£7,500 | — |
| Net upfront cost | £2,500 | £2,500 |
With the BUS grant, the upfront cost is roughly equal.
5-year running costs
At 2025 prices (electricity 28p/kWh, gas 7p/kWh, heat pump SCOP 3.4, boiler efficiency 90%):
| Heat pump | Gas boiler | |
|---|---|---|
| Annual energy cost | ~£988 | ~£933 |
| 5-year energy total | ~£4,940 | ~£4,665 |
| Annual servicing | ~£120 | ~£100 |
| 5-year servicing | ~£600 | ~£500 |
5-year total cost of ownership
| Heat pump | Gas boiler | |
|---|---|---|
| Upfront | £2,500 | £2,500 |
| 5-year running | £4,940 | £4,665 |
| 5-year servicing | £600 | £500 |
| Total | £8,040 | £7,665 |
The gap is small and narrows as electricity prices fall relative to gas. For well-insulated homes or those using a heat pump tariff, the heat pump is already cheaper to run.