Home energy guide
Heat pump vs gas or oil boiler: running costs in the UK
Against mains gas, a heat pump costs about the same to run on a standard tariff. Against oil it's usually cheaper. Your tariff, the grant and how efficiently the heat pump really runs decide which way it tips.
Last updated:
Work out your own numbers with the heat pump calculator →
Gas vs heat pump: roughly a tie, with tie-breakers
A unit of heat from a gas boiler costs about 9.4p. From an average heat pump on a standard tariff, it's about the same; from a well-designed one, about 7.5p. Oil is pricier at about 12.8p.
See the numbers
| System | Fuel price | Efficiency | p per kWh of heat |
|---|---|---|---|
| Gas boiler | 7.97p/kWh | 85% | 9.4p |
| Oil boiler | 113p/litre (≈10.9p/kWh) | 85% | 12.8p |
| Heat pump, standard tariff | 26.32p/kWh | SCOP 2.8 | 9.4p |
| Heat pump, standard tariff | 26.32p/kWh | SCOP 3.5 | 7.5p |
Gas and electricity: Ofgem cap averages, GB, Direct Debit (gas incl. 5% VAT; electricity 0% VAT from 1 Oct 2026 to 30 Jun 2027, HMRC VAT Notice 701/19, checked 2 Nov 2026). Oil: BoilerJuice England regional averages, October 2026. Efficiencies are our assumptions; SCOP 2.8 is the median measured in the Electrification of Heat trial.
The heat pump pulls ahead if:
- you disconnect the gas, saving the 29.68p a day standing charge (about £108 a year);
- the system is designed for low flow temperatures, so it reaches a SCOP of 3 or more;
- you use a heat pump or time-of-use tariff. The Energy Saving Trust says this can make a heat pump cheaper to run than a gas boiler.
The Boiler Upgrade Scheme
In England and Wales you can get £7,500 off an air or ground source heat pump. Until March 2027, homes on oil or LPG with no mains gas get an extra £1,500.
There's also £5,000 for a biomass boiler and £2,500 for an air-to-air heat pump. It's one grant per property, hybrids don't qualify, and your MCS-certified installer applies for you (GOV.UK, checked 27 Oct 2026). Scotland has separate loans and grants. The Northern Ireland Boiler Replacement Scheme is closed.
Upfront cost
The Energy Saving Trust puts a typical air source heat pump at about £12,000 fitted, or about £4,500 after the grant. If your boiler needs replacing anyway, compare that with a new boiler's price, not with nothing.
Example: a gas-heated home
A typical gas home pays about £1,027 a year for heating; with an average heat pump, about £921. That's roughly £106 a year saved, or about £290 with a well-designed system. If the heat pump costs £1,500 more than a new boiler after the grant, it pays back in about 15 years.
See the numbers
A home using 11,500 kWh of gas a year needs about 9,800 kWh of heat. Gas: 11,530 kWh × 7.97p + £108 standing charge ≈ £1,027. Heat pump at SCOP 2.8: 3,500 kWh × 26.32p ≈ £921 (after disconnecting the gas). At SCOP 3.5 the saving rises to about £290 a year.
Example: an oil-heated home
Here the heat pump shines: about £338 a year cheaper to run. With the bigger £9,000 grant, a £12,000 heat pump costs £3,000, about the same as a new oil boiler.
See the numbers
The same heat from oil needs about 1,114 litres a year at 113p ≈ £1,259. The heat pump costs about £921.
Before you decide
- Ask for a room-by-room heat loss survey and the design flow temperature, not just a price.
- Check what the quote includes: radiators, hot-water cylinder, electrical work.
- Get at least three quotes from MCS-certified installers.
- Adding solar too? Try the solar calculator.
Sources (checked 27 October 2026 unless stated)
- Ofgem price cap, 1 Oct–31 Dec 2026 (published 26 Aug 2026)
- GOV.UK: Boiler Upgrade Scheme, what you can get
- Energy Saving Trust: Air source heat pumps
- BoilerJuice regional heating-oil averages (October 2026 averages)
- Energy Systems Catapult: Electrification of Heat demonstration (2023), median SCOP — not re-checked today
- Ofgem typical domestic consumption values (gas 11,500 kWh) — not re-checked today