Heat pump vs gas boiler — the numbers, and every grant that changes them

Heat pump vs gas boiler: the 2026 running-cost maths

At the July 2026 price cap, electricity costs 3.6 times as much per kWh as gas. A heat pump only wins if it delivers more than 3.6 kWh of heat per kWh of electricity. Whether yours does is a question about your radiators and your flow temperature — not about the brand.

The number that decides it

Electricity 26.11p/kWh ÷ gas 7.33p/kWh = 3.56. That is your break-even SCOP. Below it a heat pump costs more to run than a 90%-efficient condensing boiler; above it, less. Field SCOPs on existing radiators at 50 °C flow tend to land near 3.0. On underfloor heating at 35 °C they reach 3.9.

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Compare at least three installers. Ask each one for the heat-loss calculation and the design flow temperature in writing — that number decides your running cost more than the brand on the box.

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Why the grant database is the point

There is no API for grant amounts. Not in the UK, not in Germany, not in the Netherlands, not in Czechia. Every figure on this site was read off a government page by a human and stamped with the date it was read. That is also why it is right more often than the aggregators.

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