Heat pumps: cheaper bills, cleaner air, and cosy living

Cut carbon emissions by around 80% with a heat pump:

This is the typical reduction in heating carbon emissions using an electric powered heat pump compared to a gas boiler, based on the following calculation:
Gas CO2 = (A*D) = 2.42 tonnes per year
Electricity CO2 = (A/B*C*E) = 0.40 tonnes per year
Carbon saving = 2.01 tonnes or 83%

Where A - E are:
A - 11,500 Ofgem medium gas usage
B - 330% typical seasonal coefficient of performance from a fleet of Octopus low temperature heat pumps
C - 85% typical gas boiler efficiency from a BEIS study
D - Gas fuel emissions of 210 gCO2/kWh (SAP 10.2)
E - Electricity fuel emissions of 136 gCO2/kWh (SAP 10.2)

These are typical install efficiencies for gas boilers and low temperature heat pumps installed in real homes (like Cosy Eco). See our heat pump savings blog for the full set of calculations and assumptions.

Efficiency / A heat pump is up to 4x more efficient than a gas boiler:

Octopus Cosy heat pumps can deliver several units of heat for each unit of electricity. For every 1 kWh of electricity you put in, you could get an average of 3.3kWh heat out, which is an efficiency of 330%! All our heat pumps are tested independently by the Building Research Establishment (BRE) and their energy efficiency ratings, called Seasonal Coefficient of Performance (SCOP), are publicly available on the Microgeneration Certification Scheme (MCS) product database. When we design a system, we design to a 3.4 SCOP in-situ standard.

Heat pumps don't create heat, but move existing heat from nature into your home (like an air conditioner or refrigerator, but in reverse). When you burn stuff to generate heat (like gas, oil, or wood), you are instead creating heat by converting matter to energy - so you can never get more than one unit of heat for each unit of energy you burn. Gas boilers in UK homes are only around 85% efficient, so for every 1 kWh of gas you put in, you get around 0.85kWh of heat out, which is nearly 4x less efficient than a heat pump.

These are typical install efficiencies for gas boilers and low temperature heat pumps installed in real homes (like Cosy Eco). See our heat pump saving blog for the full set of calculations and assumptions.

Heat pumps vs gas boilers

Lifespan: the expected lifespan of a gas boiler is 10-15 years. A heat pump lifetime is typically 20 years based on a UK government study. Various research from brands such as Carrier and Daikin have also found that a heat pump lifespan is typically between 15 to 20 years.
Heating costs: Based on a low temperature air source heat pump (Cosy Eco). Check out our blog on heat pump running costs for a full breakdown of our running cost calculations.
Efficiency & emissions: See above

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.

Homes with a heat pump have cleaner air

Research shows that using a heat pump to power heating and cooking emits less harmful nitrous oxide (which has been identified in the report as a contributor to asthma and other respiratory illnesses) when compared to using a gas boiler for this. For more info see Sustainable Markets Initiative Cleantech homes report.

Our customer testimonials:

Customer testimonials are from Octopus Energy's survey of heat pump customers, conducted in January 2025

Save around £370 a year with a heat pump compared to a gas boiler

We expect a medium use home to save around £368 a year, running a Cosy Eco heat pump on our Cosy Octopus 12 month fixed tariff with no gas supply, compared to a gas boiler on a standard tariff. See the our heat pump savings blog for full details and calculations.

The UK's most awarded energy supplier

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

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 Land Registry. Therefore, a 2-3% value increase for an average house priced at £265,497 would be between £5,310 and £7,965.

We're the largest installer (No.1) on the Boiler Upgrade Scheme, in England and Wales

*Based on Octopus benchmarking volume of installs against Ofgem reports from 2024, and we continue to grow.