Heat pump SCOP compared by brand: what the numbers do to your bill

Quick answer: At the October to December 2026 price cap, a heat pump needs a real-world SCOP above about 2.81 to beat an 85% efficient gas boiler on unit rates alone. Brand SCOPs at 35°C run from 4.54 to 5.45. At 55°C they collapse to between 3.29 and 3.97, which is where the money is actually decided.

We haven’t tested any of these units. The figures are manufacturer-published SCOPs from datasheets and installation manuals, checked on 28 July 2026. The bill calculations are our own modelling and are estimates.

What SCOP is, in one paragraph

COP is the ratio of heat out to electricity in at one moment; SCOP is the same ratio averaged across a whole heating season, defrost cycles and part-load running included. A SCOP of 3.5 is 3.5 kWh of heat per kWh of electricity. That’s the closest single number to what you’ll actually pay, and it’s always quoted against a flow temperature, which is the part almost everyone skips when they compare one brand with another.

Published SCOP by brand

Two SCOPs, two different tests

Look at the last column. Samsung, Mitsubishi and Worcester quote MCS-listed SCOPs, which is what goes on your grant paperwork. LG, NIBE, Grant and Daikin quote EN 14825. The MCS figure is usually the more conservative of the two.

So LG’s 5.45 and Worcester’s 4.54 are not a fair fight, and any league table that puts them in one column without saying so is selling you something. Compare within a testing basis, or accept that cross-basis comparisons are directional only. This is the main reason we don’t publish a single ranked list of brands by efficiency.

What SCOP does to your bill

Take a house needing 12,000 kWh of heat a year, which is a typical three-bed semi. Electricity is 26.32p/kWh under the price cap running from 1 October to 31 December 2026. Gas is 7.97p/kWh.

The break-even sits at about SCOP 2.81. Below that, the heat pump costs more to run than the boiler. Above 3.5, you’re saving a couple of hundred pounds a year, and above 4.5 you’re saving real money. Removing the gas standing charge of 29.68p a day adds another £108 a year to the heat pump side if you go fully electric.

None of that includes a heat pump tariff. Several suppliers offer cheaper electricity rates for heat pump households, which moves the arithmetic significantly. Our review of the Octopus Cosy tariff works through one of them. Full method for all our cost modelling is on how we calculate costs.

The number your installer controls

Here’s the part that matters more than brand. Every 1°C you take off your design flow temperature is worth roughly 2 to 2.5% on running cost. Moving from a 55°C design to 45°C is worth somewhere between 0.6 and 1.0 on your SCOP.

Look at the table again. The spread between best and worst brand at 55°C is 3.97 to 3.29, a difference of 0.68. Running the same machine at 45°C instead of 55°C moves it about as far. So your installer’s design decisions are worth roughly as much as your brand choice, and they cost a great deal less to get right.

Which is why the useful questions at quote stage are: what design flow temperature have you assumed, which radiators need changing to achieve it, and what SCOP does the MCS listing give at that temperature. An installer who can answer all three is worth more than a badge.

What to take from this

Ignore 35°C SCOPs unless you have underfloor heating throughout. Compare units at the flow temperature your house will actually run at, within the same testing basis, and treat anything above 5.0 in marketing copy as a laboratory result rather than a promise. Then spend the money you’d have paid for a premium badge on bigger radiators and better insulation. On these figures that’s worth more than the 0.68 separating the best brand from the worst at 55°C, and it works on whatever box you end up buying.

For the units themselves, see our brand comparison, the deeper explanation in COP explained, or the numbers behind UK installations on our statistics page.

FAQs

What is a good SCOP for a UK heat pump?

Anything above 3.5 at your design flow temperature is respectable, and above 4.0 is good. Field monitoring generally finds real installations running below their datasheet figure, so treat the published SCOP as a ceiling rather than an expectation.

Why is my heat pump’s real SCOP lower than the brochure?

Usually design flow temperature, cycling from an oversized unit, or a poorly set weather compensation curve. Occasionally hot water reheat at high temperature is dragging the seasonal average down. All three are fixable, and none of them are the manufacturer’s fault.

Does SCOP include hot water?

No. The SCOP figures on datasheets cover space heating only. Hot water has a separate water heating efficiency rating and a declared load profile, and it usually runs at a lower efficiency because the cylinder needs a higher temperature than the radiators.