Heat pump vs gas boiler: the real running-cost comparison (2026)

At standard 2026 price-cap rates a heat pump is roughly cost-neutral to slightly cheaper than a gas boiler for the same home. A typical 3-bed semi costs about £895 a year on a heat pump versus about £1,083 on gas once the gas standing charge is included. The real savings come from a heat-pump electricity tariff, the government grant, and dropping the gas supply altogether, not from the standard tariff alone.

The worked example: a 3-bed semi

Take a 3-bedroom semi-detached home needing 12,000 kWh of heat a year. Here is the cost both ways using the Ofgem price cap for 1 July to 30 September 2026 on a Direct Debit tariff.

A gas boiler is about 90% efficient, so it burns 12,000 / 0.9 = 13,333 kWh of gas. At 7.33p per kWh that is about £977 a year in fuel. Add the gas standing charge of about 29p a day, roughly £106 a year, and the total is about £1,083.

A heat pump at SCOP 3.5 uses 12,000 / 3.5 = 3,429 kWh of electricity. At 26.11p per kWh that is about £895 a year, with no separate heating standing charge if you no longer keep a gas supply.

So on the standard cap the heat pump saves roughly £190 a year if you remove the gas supply, and is roughly cost-neutral if you keep gas and carry on paying its standing charge.

A side-by-side comparison

	Gas boiler	Heat pump (SCOP 3.5)	Heat pump on heat-pump tariff
Unit price	7.33p/kWh	26.11p/kWh	about 13p to 15p/kWh
Efficiency	about 90%	about 350%	about 350%
Heat needed	12,000 kWh	12,000 kWh	12,000 kWh
Fuel used	13,333 kWh	3,429 kWh	3,429 kWh
Fuel cost a year	£977	£895	about £450 to £510
Standing charge	about £106 (gas)	none extra	none extra
Total a year	about £1,083	about £895	about £450 to £510

Why the SCOP matters so much

The whole comparison turns on one fact: electricity costs far more per unit than gas. At 26.11p against 7.33p, electricity is about 3.6 times the price of gas per kWh.

That sets a clear break-even point. A heat pump only beats gas if it delivers enough heat per unit of electricity to overcome that price gap. As a rule of thumb, the SCOP needs to be near 3.6 just to match gas unit for unit.

The picture improves slightly once you allow for the boiler. Because a gas boiler is only about 90% efficient, the true break-even SCOP is closer to 3.2. Above that, a heat pump is cheaper on fuel; below it, gas wins. A well-installed system at SCOP 3.5 sits just above break-even, which is why the figures come out close on the standard cap. A poorly set up system running at SCOP 3.0 would cost more to run than gas.

This is the honest position. On the standard price cap, a heat pump is not a dramatic money-saver against a modern gas boiler. It is roughly level, tipping into modest savings with a good install.

Where the real savings come from

A heat-pump electricity tariff

Several suppliers sell electricity aimed at heat pumps at around 13p to 15p per kWh. For the 3-bed semi, that drops the running cost from about £895 to roughly £450 to £510 a year, well below the £1,083 gas total. This is the biggest single change you can make.

Removing the gas standing charge

If the heat pump is your only heating and you close the gas account, you stop paying about £106 a year in gas standing charges. That alone turns a cost-neutral result into a clear saving.

The Boiler Upgrade Scheme grant

The grant covers a large slice of the install cost: £7,500 towards an air source heat pump in England and Wales, rising to £9,000 for homes replacing oil or LPG from 21 July 2026. Your installer must be MCS certified and applies for the grant on your behalf, so it comes off the price you pay. This does not change the running cost, but it changes the overall value of switching.

The bottom line

Against a gas boiler, a heat pump on the standard cap is roughly cost-neutral to about £190 a year cheaper for a typical 3-bed semi, mainly because electricity costs about 3.6 times as much as gas per unit and you need a SCOP of around 3.2 to 3.5 to break even. The meaningful savings appear when you add a heat-pump tariff, drop the gas standing charge, and take the grant. All figures here are estimates based on the Ofgem price cap and will vary with your home, install and tariff.