Heat Pump vs Gas Boiler Calculator
Compare what it costs to heat your home each year with an air source heat pump or a gas boiler, and how long any saving takes to pay back the installation.
A gas boiler turns each kWh of gas into slightly less than a kWh of heat. A heat pump turns each kWh of electricity into several kWh of heat. So what matters is the price ratio: electricity at 26.32p is 3.3 times the price of gas at 7.97p.
- With a 90% efficient boiler, heat from gas costs about 8.9p per kWh.
- A heat pump matches that at a SCOP of about 3.0. Above that it's cheaper to run; below it, dearer.
- On a heat pump or time-of-use tariff at 15p per kWh, even a SCOP of 2 would beat gas.
For a typical home using 11,500 kWh of gas a year, a SCOP of 3.2 saves roughly £65 a year at price cap rates. That's modest. The bigger savings come from a cheaper electricity tariff, pairing with solar panels, or removing the gas standing charge altogether.
Is a heat pump cheaper to run than a gas boiler?
It depends on how efficient the heat pump is and what you pay for electricity. At the October 2026 price cap, a gas boiler at 90% efficiency delivers heat for about 8.9p per kWh. A heat pump with a seasonal efficiency (SCOP) of 3 delivers it for about 8.8p, so running costs are similar. A well-designed system with a SCOP of 3.5 or more, or a heat pump electricity tariff, makes it cheaper.
What is SCOP?
The seasonal coefficient of performance is how many units of heat a heat pump produces for each unit of electricity over a whole year. A SCOP of 3 means 3kWh of heat for every 1kWh of electricity. Good installations with correctly sized radiators and low flow temperatures often reach 3 to 4.
How much is the Boiler Upgrade Scheme grant?
The Boiler Upgrade Scheme gives £7,500 towards an air source or ground source heat pump in England and Wales. Until March 2027 there is an extra £1,500 if your home is heated by oil or LPG and has no mains gas. Your installer applies for it and takes it off the price.
Do I save the gas standing charge?
Only if you have the gas supply capped or removed completely, for example if you also switch to electric cooking. Then you save the daily gas standing charge, about £108 a year at 29.68p a day.
Sources: Ofgem price cap rates and GOV.UK: Boiler Upgrade Scheme. Installation costs vary widely, so get quotes from MCS-certified installers.