Do heat pumps actually save money? The SCOP break-even, worked (2026)

At the Ofgem price cap for October to December 2026 a heat pump costs less to run than a gas boiler for the same home, as long as it runs efficiently. A typical 3-bed semi costs about £902 a year on a heat pump versus about £1,171 on gas once the gas standing charge is included. A heat-pump electricity tariff, the government grant and dropping the gas supply altogether make the case stronger still.

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 October to 31 December 2026 on a Direct Debit tariff. Gas prices include 5% VAT; there is no VAT on electricity from 1 October 2026 to 31 March 2027.

A gas boiler is about 90% efficient, so it burns 12,000 / 0.9 = 13,333 kWh of gas. At 7.97p per kWh that is about £1,063 a year in fuel. Add the gas standing charge of 29.68p a day, roughly £108 a year, and the total is about £1,171.

A heat pump at SCOP 3.5 uses 12,000 / 3.5 = 3,429 kWh of electricity. At 26.32p per kWh that is about £902 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 £269 a year if you remove the gas supply, and about £160 a year 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	7.97p/kWh	26.32p/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	£1,063	£902	about £450 to £510
Standing charge	about £108 (gas)	none extra	none extra
Total a year	about £1,171	about £902	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 26.32p against 7.97p, electricity is about 3.3 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 3.3 just to match gas unit for unit.

The picture improves once you allow for the boiler. Because a gas boiler is only about 90% efficient, the true break-even SCOP is about 3.0 (26.32 x 0.9 / 7.97 = 2.97). A system running at about SCOP 3.0 would roughly match gas; below that gas wins. A well-installed system at SCOP 3.5 sits clearly above break-even, which is why the heat pump comes out ahead on the standard cap.

This is the honest position. On the standard price cap, a heat pump at SCOP 3.5 now sits clearly above break-even against a modern gas boiler, with a saving of roughly £160 to £270 a year for a typical 3-bed semi. That is a real saving but not a dramatic one, and a poorly set up system running near SCOP 3.0 would lose most of it.

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 £902 to roughly £450 to £510 a year, well below the £1,171 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 £108 a year in gas standing charges. That alone lifts the saving from about £160 to about £270 a year.

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. From 21 July 2026 until March 2027 it rises to £9,000 for homes heated by oil or LPG that have no mains gas connection. Scotland has its own scheme through Home Energy Scotland. 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 October to December 2026 standard cap is about £160 to £270 a year cheaper for a typical 3-bed semi. Electricity costs about 3.3 times as much as gas per unit, so a heat pump needs a SCOP of about 3.0 to break even, and a typical SCOP of 3.5 clears it. The bigger 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.

Want the same comparison run on your own house rather than a 3-bed semi? Use the heat pump vs gas boiler running cost comparison, which prices both against your property, bedrooms and region.