What does a heat pump really cost to run?
Compare a heat pump with your gas boiler at today’s energy prices. No sales pitch from an installer, just the sums.
The three numbers that decide it
Ofgem price cap, 1 October – 31 December 2026, Direct Debit average (source). Break-even assumes a boiler that is 85% efficient and ignores standing charges.
Running costs by home
| Home | Gas boiler | Heat pump, standard tariff | Heat pump, Cosy Octopus |
|---|---|---|---|
| 2-bed flat | £706 | £479 | £357 |
| 2-bed terraced house | £826 | £575 | £428 |
| 3-bed semi-detached house | £1,025 | £735 | £547 |
| 3-bed detached house | £1,224 | £895 | £666 |
| 4-bed detached house | £1,463 | £1,087 | £808 |
Yearly heating and hot water. Heat pump at SCOP 3.5. Gas includes the standing charge. All home types →
How we work it out
- Take the gas your boiler uses in a year and multiply by 0.85 to get the heat your home actually needs.
- Divide that heat by the heat pump’s efficiency (SCOP) to get the electricity it would use.
- Multiply by the price of electricity on a standard tariff and on a heat pump tariff.
Common questions
How much does a heat pump cost to run per year?
For a typical 3-bed semi-detached house, about £735 a year on a standard electricity tariff or about £547 on a heat pump tariff, assuming a good installation (SCOP 3.5). The same home costs about £1,025 a year to heat with a gas boiler, including the gas standing charge.
Is a heat pump cheaper to run than a gas boiler?
It depends on how efficient the installation is. At today’s prices electricity costs about 3.3 times as much as gas per kWh, so a heat pump needs a SCOP of about 2.8 or better to match a gas boiler on a standard tariff. On a heat pump tariff the break-even is lower, around 2.1.
How much electricity does a heat pump use?
A 3-bed semi-detached house needing about 9,775 kWh of heat a year would use roughly 2,793 kWh of electricity at a SCOP of 3.5.
What is the cheapest tariff for a heat pump?
Time-of-use tariffs made for heat pumps are usually cheapest. Cosy Octopus has three cheap windows a day priced 51% below its day rate, so a heat pump scheduled to run mostly in those windows pays much less per kWh.
Are these figures exact?
No. They are estimates from typical gas use for each home type, a boiler efficiency of 85% and the current price cap rates. Insulation, radiators, weather and how the system is set up all make a big difference.
Run your heat pump on cheaper electricity
Cosy Octopus has three cheap windows a day, priced 51% below its day rate. Switch through our referral link and you also get £50 credit.
Get an Octopus Quote + £50 Credit →You need a heat pump and a smart meter. Link checked 5 October 2026.