99% of Octopus Cosy heat pump owners pay less to heat their homes than they would with gas
Real-world data for all Cosy customers shows 99.6% of Octopus Cosy heat pump customers pay less to heat their homes than they would with a gas boiler
All Octopus Cosy heat pumps report their actual performance data – enabling real-world comparison to gas boilers
Heat pumps set to pull even further ahead from 1st October, when VAT on electricity falls to 0%
Octopus customers on its smart Cosy tariff are saving £227 a year on average
Comes as more than half a million Brits inquired about getting a heat pump last year
London, 2nd September 2026 – Nearly every household with an Octopus heat pump is heating their home for less than they would with a gas boiler.
Live data from thousands of Octopus’ ‘Cosy’ heat pumps – publicly available via Octopus performance fleet dashboard – shows a whopping 99.6% of customers are paying less to heat their homes than they would with a gas boiler.
And the savings could get even bigger this winter.
From 1 October, VAT on electricity is set to fall to 0% thanks to a recent government intervention to bring bills down, while gas will remain at 5% – giving heat pumps an extra boost as millions of households switch their heating back on.
Heat pump owners can save even more by pairing it with a smart tariff to take advantage of cheaper electricity at different times of the day.
Customers on Octopus’ popular smart heat pump tariff Cosy are saving an average of £227 a year compared with heating their homes with a gas boiler.
The new data comes as energy bills remain under pressure following Ofgem's latest increase to the energy price cap.
As energy costs remain high, Brits are looking for cheaper, cleaner ways to heat their homes – with more than 550,000 enquiring about getting a heat pump from Octopus in the past year alone.
Rebecca Dibb-Simkin, Chief Product Officer at Octopus Energy, said: “For years, sceptics have said heat pumps are expensive to run, so we took the groundbreaking decision to put all our Cosy heat pump real-world performance online.
“Across the thousands of homes with a Cosy, 99.6% are paying less to heat their homes than they would with a gas boiler.”
“With new heat pump technology operating at the same temperature as a gas boiler, and the government removing VAT from electricity bills, there’s ever more reason for people to choose heat pumps.”
The figures come from data collected across all homes using Octopus' Cosy heat pump, with results tracked on its live Cosy fleet performance dashboard. It shows that heat pumps comfortably outperform gas boilers on efficiency, seasonal performance and running costs.
Designed and manufactured here in the UK, Octopus’s award-winning Cosy heat pump can also be remotely upgraded – just like a smartphone – allowing it to further improve and gain more features long after installation.
One recent software update, ‘Hush Mode’, lets customers switch their heat pump into a whisper-quiet setting with a single tap in the Octopus app.
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Notes to the editor:
The new Cosy performance dashboard uses anonymised, aggregate data from Cosy heat pump systems from 1 September 2025 to 31 August 2026 across Great Britain and the rates of the Cosy Octopus smart tariff over the same time period.
Cosy systems generated more than 4kWh of heat for every 1kWh of electricity used, delivering a coefficient of performance (COP) of 3.97. This compares with a generally accepted COP of 0.85 for a gas boiler, meaning Cosy heat pumps operated at around 4.7 times the efficiency of a gas boiler over the same period.
The dashboard also enables users to drill down into regional performance across Great Britain and performance levels at different external temperatures.
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About Octopus Energy Group
Octopus Energy is a global clean energy and technology business, driving the affordable, green energy system of the future. Under its own retail brand, Octopus delivers world-class customer service and cutting-edge energy products to 11 million households globally.
The company is driving the electrification of heat and transport through smart tariffs and innovative clean tech, with operations spanning 27 countries and the entire energy value chain. It operates a £8.5 billion renewables portfolio as well as thriving EV leasing, heat pump, and solar businesses.
Backed by pension funds, investors and energy giants, Octopus Energy Group businesses deliver cheaper, greener energy and cutting-edge tech to countries and customers worldwide. For more information, check out our website.