Estimate air source heat pump running costs in the UK and compare yearly electricity cost against a gas boiler, using your own energy prices.
Heat pump running costs · SCOP based · vs gas boiler
Use your yearly gas use in kWh from a recent bill if you have it.
Take your annual heat demand in kWh, multiply by your boiler efficiency to get useful heat, divide by the heat pump's SCOP to get the electricity it needs, then multiply by your electricity price. A typical UK home using about 12,000 kWh of heat a year spends roughly £850–£1,000 running an air-source heat pump at a SCOP of 3.2 and 24.5p electricity.
Because a heat pump turns 1 unit of electricity into 3–4 units of heat, its running cost can rival a gas boiler even though electricity costs more per kWh than gas.
Searches for air source heat pump cost often mix two different questions: the upfront installation cost and the yearly running cost. This calculator answers the running-cost question by estimating annual electricity use from your heat demand and SCOP.
For a fair quote decision, compare both numbers separately. Installation cost is a one-off capital cost; running cost is what you pay every year and depends heavily on electricity price, heat demand and system efficiency.
SCOP (Seasonal Coefficient of Performance) is the average heat output per unit of electricity across the heating season. A SCOP of 3.2 means 3.2 kWh of heat per 1 kWh of electricity. Every 0.5 you add to SCOP cuts running cost by roughly 12–15%.
Bigger radiators, lower flow temperatures, and a well-sized system all raise SCOP. An undersized or rushed install can drag it down to 2.5, which is where heat pumps get an unfair “expensive” reputation.
A typical UK home using around 12,000 kWh of heat a year will spend roughly £850–£1,000 a year running an air-source heat pump at an electricity price of about 24.5p/kWh and a seasonal efficiency (SCOP) of 3.2. Your figure depends on how well insulated your home is, the heat pump's SCOP, and your electricity tariff. Enter your own numbers in the calculator above for a tailored estimate.
Heat pump cost can mean either the upfront installation price or the ongoing running cost. This calculator focuses on running costs: the electricity needed each year to heat your home. Installation cost, grants, servicing and finance are separate. If you searched for air source heat pump cost, use this page for the annual running-cost part of the decision.
It depends on the price gap between electricity and gas. Because a heat pump delivers 3–4 units of heat per unit of electricity, while a gas boiler delivers less than one unit of heat per unit of gas, a heat pump can match or beat gas running costs even though electricity costs more per kWh. At a SCOP of 3.2, 24.5p electricity and 6p gas, running costs are often close to break-even; a higher SCOP or a cheaper heat-pump tariff tips it in the heat pump's favour.
SCOP (Seasonal Coefficient of Performance) is the average units of heat a heat pump produces per unit of electricity across a whole heating season. A SCOP of 3.2 means 3.2 kWh of heat for every 1 kWh of electricity. Higher is better and directly lowers your running cost. A well-designed system on radiators sized for low flow temperatures might reach 3.5–4.0, while an undersized or poorly installed system might only manage 2.5.
The easiest way is to look at your current annual gas use in kWh on a recent bill or your online energy account, and subtract a small amount for cooking if you cook with gas. The calculator can use that gas figure directly, or you can pick a home-size preset for a typical estimate (around 8,000 kWh for a flat up to 22,000 kWh for a large detached house).
Yes. Several UK suppliers offer heat-pump or time-of-use tariffs with a lower unit rate for part of the day. Running the heat pump more during cheaper periods can cut annual costs noticeably. Try entering a lower blended electricity price in the calculator to see the effect.
No. This tool estimates ongoing running costs only, so you can compare a heat pump against a gas boiler year to year. Installation cost and schemes such as the Boiler Upgrade Scheme grant are separate one-off figures and vary by property and installer.
