Cosy, green & cost effective heat pumps

Cosy heat pump customers on the Cosy Octopus tariff saved an average of £200 last year compared to using a gas boiler running at 85% efficiency on our standard variable tariff

This figure is based on the actual energy consumption of all Cosy heat pump customers on a Cosy Octopus tariff between 1 July 2025 and 1 July 2026, using tariff rates at the time.

We compared this to the cost of producing the same amount of heat with a gas boiler operating at 85% efficiency, priced using our Flexible Octopus (standard variable) tariff at the same time.

Savings from gas standing charges were included only for customers who had fully removed their gas supply (less than 3% of customers). Actual savings vary depending on system design, tariff choice, home insulation, and energy use.

Our typical heat pump price is £4,459, which is lower than the national average of £5,600

This is the median post-survey price from all of our heat pump quotes after the £7,500 Boiler Upgrade Scheme has been applied, between 01/09/2025 and 28/02/2026. The national average is taken from the Boiler Upgrade Scheme statistics: April 2026 – median cost of installation Q4 2025.

Cut carbon emissions by 82% with a heat pump

This is the typical reduction in heating carbon emissions using an electric powered heat pump compared to a gas boiler.

The carbon breakdown

• Gas CO2 (tonnes per year) - 2.42
• Electricity CO2 (tonnes per year) - 0.43
• Carbon saving (tonnes per year) - 1.99

Data sources and assumptions

• Gas Energy Usage (kWh) 11500 (Ofgem medium use gas usage (Jun 2026))
• Heat Pump Efficiency 312% (typical seasonal coefficient of performance from a fleet of Octopus high temperature heat pumps)
• Gas Boiler Efficiency 85% (The typical gas boiler efficiency from a BEIS study)
• Gas fuel emissions of (gCO2/kWh) 210 (SAP 10.2)
• Electricity fuel emissions of (gCO2/kWh) 136 (SAP 10.2)

Based on these sources, heat pumps typically produce lower operational emissions when heating the home than gas boilers.

For more information, explore our Octopus Cosy heat pump fleet performance dashboard.

We're the largest heat pump installer on the Boiler Upgrade Scheme

Based on Octopus benchmarking against Ofgem reports from 2024 and we've continued to grow since.

Our customers love their heat pumps!

• 93% of people say it's the same or more comfortable than their previous boiler
• 87% say it costs the same to run or less
• 83% say it's the same noise or less than the previous boiler
• 90% say it's just as easy or easier to maintain

We survey all our heat pump customers 3 months post-installation to see how they find their heat pump compared to their previous gas boiler. Survey results are taken from a sample of 2,837 customers:

• Comfort: 93% of people say it is the same or more comfortable than their previous boiler.
• Running Costs: 87% say it costs the same to run or less.
• Noise: 83% say it is the same noise or less than the previous boiler.
• Maintenance: 90% say it is just as easy or easier to maintain.

A heat pump is around 4x more efficient than a gas boiler

Heat pumps don't generate heat by burning fuel. Instead, they transfer existing heat into your home. This means they can deliver multiple units of heat for each unit of electricity used.

Based on performance data from a fleet of installed Octopus Cosy heat pumps, typical real-world seasonal performance (SPF or SCOP) is around 3.6. This means around 3–4 kWh of heat is delivered for every 1 kWh of electricity used (an effective efficiency of 300–400%). By comparison, typical UK domestic gas boilers operate at around 85% efficiency, delivering approximately 0.85 kWh of heat per 1 kWh of gas used. On this basis, a heat pump can be around 4× more efficient than a typical gas boiler.

All our heat pumps are independently tested by the Building Research Establishment (BRE), with SCOP values published on the Microgeneration Certification Scheme (MCS) product database. Actual efficiency will vary depending on the property, system design, and usage. For more information, explore our Octopus Cosy heat pump fleet performance dashboard.

The UK's most awarded energy supplier

We've won more awards for customer service more awards for customer service than anyone else.

Heat pumps give reliable, consistent heating and hot water

The heat pump user survey report by Nesta from May 2023 summarises that "users are highly satisfied with their heat pumps". It states: "People living in England, Scotland and Wales who own their home and use a heat pump to heat it are satisfied that heat pumps are safe, reliable, quiet heat sources that are effective for space heating and producing hot water." Find the full report here.

The Cosy heat pump is quiet

Heat pump sound power levels are verified by an independent, third-party laboratory as part of the testing process for inclusion on the MCS product database. The laboratory verifies the sound power on the A-weighted decibel curve, as A-weighting closely aligns to how humans perceive "loudness".

All heat pumps are measured using EN14511 standards to ensure uniformity across manufacturers and models. Our Cosy 6 heat pump has a verified sound power level lower than many other heat pumps of the same capacity.

Heat pump heating makes the air healthier in your home

Homes with a heat pump emit far less harmful nitrous oxide (NOx) emissions than those with gas boilers and cookers, significantly reducing asthma and other respiratory illnesses. According to the Sustainable Markets Initiative Cleantech Homes report.

A heat pump can add thousands to your property value

Analysis by the Department of Land Economy at the University of Cambridge suggests a 16% value uplift for new-build homes with enough solar and battery storage to eliminate energy bills. A further study of over five million existing properties indicates a 2-3% value increase for existing homes with solar panels or heat pumps (versus like-for-like gas-heated homes), according to the Sustainable Markets Initiative: Cleantech Homes report, 2024.

As of April 2025, the average house price in the UK is £265,497 according to the Land Registry. Therefore, a 2-3% value increase for an average house priced at £265,497 would be between £5,310 and £7,965.

Heat pumps typically last longer than gas boilers