How Much Does a Heat Pump Cost to Run Per Month in 2026?

A typical air source heat pump costs between £50 and £100 per month to run in a reasonably insulated three-bedroom UK home in 2026, based on current electricity prices of around 24.5p per kWh. That's roughly comparable to a gas boiler for many households, and often cheaper than oil. Your actual figure depends on your home's insulation, the heat pump's efficiency, and how warm you like it.

What Determines Your Monthly Heat Pump Running Costs?

The single biggest factor is your home's heat demand, measured in kilowatt hours (kWh). A draughty Victorian terrace with no wall insulation might need 20,000 kWh of heat per year. A well-insulated 1990s semi might need 10,000 kWh.

Heat pumps don't convert electricity to heat on a 1:1 basis like an electric heater does. They move heat from the outside air or ground into your home, and they're good at it. A well-installed air source heat pump typically achieves a Coefficient of Performance (COP) of 3.0 to 3.5 across the year, meaning for every 1 kWh of electricity it uses, you get 3 to 3.5 kWh of heat.

So if your home needs 12,000 kWh of heat annually and your heat pump runs at a seasonal COP of 3.2, you'll use roughly 3,750 kWh of electricity. At 24.5p per kWh (the Ofgem price cap rate from April 2026), that's about £919 per year, or £77 per month.

But heating demand isn't spread evenly. You'll pay more in January and less in June. Expect winter months to hit £120 to £150 and summer months to drop below £20 for hot water only.

Real Monthly Running Costs for Different Home Sizes

Let's put some proper numbers on this. The figures below assume an air source heat pump with a seasonal COP of 3.0 and electricity at 24.5p/kWh.

Two-bedroom flat or small terrace (8,000 kWh heat demand):

• Electricity used: roughly 2,670 kWh/year
• Annual cost: about £654
• Monthly average: around £55

Three-bedroom semi-detached (12,000 kWh heat demand):

• Electricity used: roughly 4,000 kWh/year
• Annual cost: about £980
• Monthly average: around £82

Four-bedroom detached (18,000 kWh heat demand):

• Electricity used: roughly 6,000 kWh/year
• Annual cost: about £1,470
• Monthly average: around £123

These are averages across the full year. Ground source heat pumps tend to perform slightly better, with seasonal COPs closer to 3.5 to 4.0, which could knock 10% to 15% off those figures.

Honestly, the spread between homes is massive. A poorly insulated four-bed could cost twice what a well-insulated one does. That's why an energy assessment before installation matters so much.

How Does a Heat Pump Compare to Gas and Oil Boiler Running Costs?

This is the question everyone asks, so let's be straight about it.

Gas prices under the April 2026 Ofgem cap sit at around 6.76p per kWh. A modern condensing gas boiler runs at about 90% efficiency. For a three-bed semi needing 12,000 kWh of heat, you'd burn roughly 13,333 kWh of gas. That costs about £901 per year, or £75 per month.

So gas is slightly cheaper than a heat pump for that same house? On paper, yes, by a few pounds a month right now. But there are two things to consider.

First, electricity prices are expected to fall relative to gas over the coming years as the grid gets greener and the government shifts policy. There's active discussion about rebalancing energy levies off electricity bills, which could cut heat pump running costs by 15% or more.

Second, oil is a different story entirely. Heating oil has bounced between 55p and 75p per litre over the past couple of years. At 65p per litre and a boiler efficiency of 85%, running that same three-bed semi on oil costs around £1,150 to £1,300 per year. A heat pump saves £200 to £350 a year compared to oil, even at today's electricity prices.

For off-gas-grid homes currently on oil, LPG, or electric storage heaters, the financial case for a heat pump is already strong.

How the £7,500 Boiler Upgrade Scheme Grant Affects the Maths

The Boiler Upgrade Scheme (BUS) offers a £7,500 grant towards the cost of an air source or ground source heat pump. It's available in England and Wales, the property must have an EPC, and the installer must be MCS certified. The scheme is currently funded through to March 2028.

A typical air source heat pump installation costs between £10,000 and £15,000 before the grant. After the £7,500 discount, you're looking at £2,500 to £7,500 out of pocket.

Let's say you're on oil, spending £1,200 a year. You switch to a heat pump costing £980 a year to run. That's a saving of £220 per year. If you paid £4,000 after the grant, you'd break even in about 18 years on running costs alone. Not spectacular.

But factor in oil boiler servicing (£100 to £200 a year), potential oil boiler replacement costs (£3,000 to £5,000 when it dies), and likely future shifts in energy pricing, and the payback shortens considerably. For homes on LPG or direct electric heating, the savings are bigger and the payback is faster.

The grant doesn't reduce your running costs directly. It reduces the upfront capital cost, which is the main barrier for most homeowners.

"Won't a Heat Pump Cost a Fortune in Winter?"

This is probably the most common worry. People picture a heat pump struggling in a British winter, guzzling electricity. Let's address it properly.

Modern air source heat pumps work efficiently down to minus 15°C or lower. Most of the UK rarely sees temperatures below minus 5°C. Yes, the COP drops in cold weather. A heat pump that delivers a COP of 4.0 on a mild October day might drop to 2.5 on a freezing January morning. But it doesn't stop working, and it doesn't suddenly become as expensive as a plug-in electric heater.

The Electrification of Heat Demonstration Project, run by the Energy Systems Catapult with real data from over 700 UK heat pump installations, found average seasonal performance factors (SPFs) of 2.8 for air source heat pumps. That's across the whole year, including the coldest months.

In practical terms, your worst winter month might cost £130 to £160 for a three-bed semi. That's more than a summer month, obviously, but it's hardly terrifying. And if you've got a time-of-use tariff like Octopus Go, running your heat pump heavily on cheap overnight electricity can bring that figure down further.

The key is proper installation and correct system design. A heat pump that's been sized correctly for your home, paired with appropriately sized radiators or underfloor heating, won't struggle. A badly installed system will cost more and perform worse. That's why choosing an MCS certified installer matters.

How to Estimate Your Own Heat Pump Running Costs

Want a rough figure for your home before you speak to an installer? Here's a simple method.

If you're on gas, check your annual gas consumption on a recent bill. It'll be listed in kWh. Multiply that figure by 0.9 (to account for boiler efficiency and get your actual heat demand). Then divide by 3 (a conservative heat pump COP). Multiply the result by 0.245 (current electricity price in pounds).

So if you use 15,000 kWh of gas: 15,000 x 0.9 = 13,500 kWh of heat. Divided by 3 = 4,500 kWh of electricity. Times 0.245 = £1,102 per year, or about £92 per month.

If you're on oil, you can estimate roughly 10 kWh per litre of oil. So 1,500 litres per year equals about 15,000 kWh. Apply the same calculation from there.

This is a rough estimate. A proper installer will do a heat loss calculation for your specific property, which accounts for insulation levels, window types, floor area, and local climate. But it gives you a ballpark before you pick up the phone.

Have you checked your gas or oil bill recently? You might be surprised how the numbers compare.

Frequently Asked Questions

How much does it cost to run a heat pump per month UK?

For an average three-bedroom home with decent insulation, expect to pay between £60 and £100 per month on average across the year. Winter months will be higher (£100 to £150) and summer months much lower (£15 to £30 for hot water). Your actual costs depend on your home's insulation, the heat pump's efficiency, and your electricity tariff.

Are heat pumps cheaper to run than gas boilers?

At current 2026 energy prices, heat pumps and gas boilers cost roughly the same to run for a well-insulated home. Gas is marginally cheaper per month right now, but the gap is small and expected to shrink as electricity prices are rebalanced. Heat pumps are already significantly cheaper than oil, LPG, and direct electric heating.

How much electricity does a heat pump use per year?

A typical air source heat pump in a three-bedroom UK home uses between 3,500 and 5,000 kWh of electricity per year. This varies based on your home's heat demand and the heat pump's efficiency. A ground source heat pump may use 10% to 15% less electricity for the same heat output due to higher efficiency.

Do heat pumps work in cold weather UK?

Yes. Modern air source heat pumps are designed to work efficiently in temperatures as low as minus 15°C to minus 25°C, well beyond what most of the UK experiences. Performance does drop slightly in very cold weather, but real-world UK data from the Electrification of Heat project shows average seasonal efficiencies of 2.8, including winter months.

Is it worth getting a heat pump in 2026?

For homes off the gas grid using oil, LPG, or electric heating, a heat pump is very likely worth it financially, especially with the £7,500 BUS grant. For homes on mains gas, the running cost savings are small right now, but the grant significantly reduces upfront costs and you'll be future-proofed against rising gas prices and potential regulatory changes.

Find a Local MCS Certified Installer

The best way to get an accurate running cost estimate for your home is to speak to a qualified installer who'll do a proper heat loss survey. Use our directory at heatpumpinstallerdirectory.co.uk to find MCS certified heat pump installers in your area, compare quotes, and make sure you're eligible for the £7,500 BUS grant before you commit to anything.