Save up to £545 a year with a heat pump
Heat pumps are the most climate-friendly way to heat your home - but how much do they cost to run? When paired with a smart, green heat pump tariff like Cosy Octopus, you could save hundreds of pounds each year. Use our calculator to compare potential running costs against a gas boiler to see how much you could save.
Check how much your home could save
How to maximise your savings
Your running costs can be dependent on a few important factors, including your choice of tariff, your installation package and how you decide to run your heating.
Plus if you’re planning to go fully electric (that means no more gas hob) you can also save a further £119 a year as you’ll no longer need to pay for the gas standing charge. Any supplier can arrange for your gas meter to be removed, but Octopus Energy is one of the only suppliers to offer this service for free.
The graph below shows an indication of predicted running costs with different installation types and tariffs, assuming you ditch your gas supply.
Your installation package options: Cosy Turbo and Cosy Eco
Exclusively with Octopus, you can now tailor your heat pump installation depending on whether you’d prefer a lower up-front cost and a less invasive installation with Cosy Turbo, or lower long-term running costs with Cosy Eco.
Cosy Turbo is a high-temperature heat pump, meaning you’ll need less radiator changes and an easier installation. Whereas Cosy Eco runs at a lower temperature, and requires more plumbing changes. Find out more and compare at our blog.
The Cosy Octopus smart tariff
Cosy Octopus works by allowing you to make the most of the cheap, green ‘Cosy’ periods. This might mean pre-heating your hot water or your home a little earlier than usual, and then once the daily peak in energy demand has passed, turning your green-heating back on to remain as cosy as ever.
We'd expect the average home to save an extra £280 by switching their heat pump and general electricity usage to a Cosy Octopus tariff.
To make the most of the tariff, all you'll need to do is set a schedule around the Cosy dip periods and you'll be good to go. Here are our top tips for how to run your heat pump to maximise savings.
How to join Cosy Octopus
If you have a heat pump, or you're planning to have one installed, switching to Cosy is easy. Just follow the guidance on this page.
Alternatively if you have other smart tech devices at home, like an EV or solar panels, a different smart tariff could make your energy cheaper. Check out this quiz to find the right tariff for you.
Check out the savings table
For a little more detail on how we came to the £545 saving, check out the cost comparison below for a large home with a Cosy heat pump, installed with the Cosy Eco installation package on our Cosy Octopus tariff with no gas supply, compared to a gas boiler on a standard tariff.
| Gas boiler: Flexible Octopus | Cosy heat pump: Cosy Octopus | |
|---|---|---|
| A - Annual heat demand | 14,161 kWh | 14,450 kWh |
| B - Heating efficiency | 85% | 330% |
| C - Annual heating energy usage | 16,660 kWh | 4,379 kWh |
| D - Annual general elec usage | 4,100 kWh | 3,811 kWh |
| E - Gas price | 6.99 p/kWh | - |
| F - Elec price | 27.03 p/kWh | 22.13 p/kWh |
| G - Gas standing charge | 32.67 p/kWh | - |
| H - Elec standing charge | 53.8p/kWh | 52.2p/kWh |
| I - Total dual-fuel energy bill | £2,612 | £2,067 |
| J - Total dual-fuel bill savings | - | £545 |
Assumptions explained
Save up to £545 a year with a heat pump compared to a gas boiler
This is the total energy bill saving for an Ofgem high use home, running a Cosy Eco heat pump on our Cosy Octopus smart tariff with no gas supply, compared to a gas boiler on a Standard tariff. See the full calculations below:
Gas Dual Fuel Bill, I = (C1*E1+D1*F1)/100+(G1+H1)*365/100
Heat Pump Dual Fuel Bill, I = (C2*F2+D2*F2)/100+(G2+H2)*365/100
Dual Fuel Bill Saving, J = 11-I2
Where A - H are:
A1/A2 = C1*B1
B1 - 85% typical gas boiler efficiency from a BEIS study
B2 - 330% typical seasonal coefficient of performance from a fleet of Octopus low temperature heat pumps
C1 - 17,000 kWh Ofgem high use gas consumption
C2 - B2/A2
D1/D2 - 4,100 kWh Ofgem high use electricity consumption
E1 - 6.99 p/kWh Ofgem price cap average gas unit rate (April 2025)
F1 - 27.03 p/kWh Ofgem price cap average elec unit rate (April 2025)
F2 - 22.13 p/kWh Cosy Octopus weighted average elec unit rate (April 2025)
G1 - 32.67 p/kWh Ofgem price cap average gas standing charge (April 2025)
H1 - 53.80 p/kWh Ofgem price cap average elec standing charge (April 2025)
H2 - 52.20 p/kWh Cosy Octopus average elec standing charge (April 2025)
Published on 3rd April 2025 by:
Hey I'm Constantine, welcome to Octopus Energy!
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