Electric Boiler vs Heat Pump: Full Cost Comparison
The short answer
- About 64% less electricity for the same heat with a heat pump than with an electric boiler
- £2,606 a year to heat a 3-bed semi with an electric boiler, against £666 with a heat pump on a heat pump tariff
- About 2 to 4 years to pay back a heat pump costing £3,500 to £8,000 after the £7,500 grant
A heat pump uses about 64% less electricity than an electric boiler to produce the same heat, at the efficiency measured in the typical home in the Electrification of Heat trial. For a 3-bed semi, that is the difference between £2,606 a year with an electric boiler and £666 with a heat pump on a heat pump tariff. With the £7,500 Boiler Upgrade Scheme grant, the heat pump pays for itself in about 2 to 4 years if you are replacing an electric boiler. Few heating swaps pay back faster.
Why is the difference so large?
An electric boiler turns 1 kWh of electricity into 1 kWh of heat, while the median heat pump in the trial gave 2.78. So heat costs 8.6p to 10.3p a unit from a heat pump, against 26.32p from an electric boiler.
Read the detail
An electric boiler converts 1 kWh of electricity into 1 kWh of heat. It is essentially a giant kettle. Every unit of heat costs you the full electricity price: 26.32p at the Ofgem price cap for October to December 2026. Many electric boilers run on Economy 10 or another off-peak meter, which lowers that price for part of the day; the figures on this page use the single rate.
A heat pump extracts heat from outside air and upgrades it using a compressor. In the Electrification of Heat trial for DESNZ, the middle half of 428 air source heat pumps delivered 2.55 to 3.05 kWh of heat for each kWh of electricity over a year, with a median of 2.78. So each unit of heat costs 8.6p to 10.3p at the same electricity price, or 6.1p to 7.3p on a heat pump tariff such as Cosy Octopus, about 18.7p per kWh with most heating in the cheap hours.
This is not a small difference. It is the difference between the most expensive and one of the cheapest heating systems available.
How much cheaper is a heat pump to run?
£2,606 a year with an electric boiler in a 3-bed semi, against £666 with a heat pump on a heat pump tariff. Even on a standard tariff, the heat pump saves £1,062 to £2,214 a year in the four example homes.
Read the detail
| Property type | Electric boiler | Heat pump (standard tariff) | Heat pump (HP tariff) | Annual saving (HP tariff) |
|---|---|---|---|---|
| 2-bed terrace | £1,658 | £596 | £424 | £1,234 |
| 3-bed semi | £2,606 | £937 | £666 | £1,940 |
| 3-bed detached | £2,771 | £997 | £708 | £2,063 |
| 4-bed detached | £3,458 | £1,244 | £884 | £2,574 |
The data behind this table
Electric boiler at 100% efficiency and 26.32p/kWh. Heat pump at the measured median efficiency of 2.78, on a standard tariff at 26.32p/kWh or an 18.7p heat pump tariff, Cosy Octopus with most heating in the cheap hours. Ofgem price cap for October to December 2026. Average insulation. Heat demand: 6,300 kWh for the 2-bed terrace, 9,900 kWh for the 3-bed semi, 10,530 kWh for the 3-bed detached and 13,140 kWh for the 4-bed detached, from the shared model behind our calculators. Standing charges are left out.
Even on a standard electricity tariff, the heat pump saves £1,062 to £2,214 a year compared with an electric boiler in these four homes. On a heat pump tariff, the savings are larger still.
Use our boiler vs heat pump calculator for your specific property.
What does each cost to install?
£11,000 to £15,500 for a heat pump, or £3,500 to £8,000 after the grant; an electric boiler costs much less. Saving £1,940 a year in a 3-bed semi on a heat pump tariff, the heat pump pays back in about 2 to 4 years.
| System | Installed cost | After the grant | What else to check |
|---|---|---|---|
| Electric boiler (new) | Much lower; get quotes | No grant | Nothing extra if the pipes and radiators stay |
| Air source heat pump | £11,000 to £15,500 | £3,500 to £8,000 | Any radiator changes or a new cylinder that are not in the installer's price |
Read the detail
The data behind this table
Heat pump costs for a 3-bed semi: the middle half of what installers reported for a heat pump of about 9 kW under the Boiler Upgrade Scheme in 2025/26, covering the system, labour and VAT. Grant of £7,500 in England and Wales. The Energy Saving Trust describes electric heating as low cost to install, but prices vary, so get quotes. See our radiator sizing guide.
The heat pump costs more upfront, but with £1,940 a year in running cost savings (3-bed semi on a heat pump tariff), it pays for itself in about 2 to 4 years after the grant, or 2.7 years at the typical cost of £5,200. Every £1,000 of radiator work adds about six months. Few heating swaps pay back this fast.
Electric boiler homes are the best case for heat pumps
If you currently heat with an electric boiler, a heat pump saves you more money a year than almost any other starting point. A 3-bed semi on gas saves £211 a year by switching to a heat pump on a heat pump tariff. The same house on an electric boiler saves £1,940.
When does an electric boiler still make sense?
In small flats with no outdoor space, homes with very low heat demand, on a tight budget or before a move. In a well-insulated 1-bed flat the saving is about £640 a year, so payback takes about 4 to 10 years.
Read the detail
Small flats with no outdoor space. If you live in a flat with no balcony, garden or external wall suitable for a heat pump outdoor unit, an electric boiler may be the practical choice: it is compact, wall-mounted and needs nothing outside. The Energy Saving Trust notes that compact heat pumps designed for small, well-insulated flats also exist, needing a cupboard of about 80cm by 80cm near an outside wall, so ask an installer before ruling one out.
Very low heat demand. A well-insulated 1-bed flat needs about 3,125 kWh of heat a year in our model, which costs about £822 with an electric boiler. A heat pump on a heat pump tariff would cost about £180, a saving of about £640 a year, so paying back the heat pump after the grant (£2,500 to £6,500) takes about 4 to 10 years. For small, efficient homes the case is weaker.
Budget constraints. If you cannot afford the upfront cost of a heat pump even after the grant, an electric boiler still heats your home. The government's Warm Homes Plan sets out zero and low interest loans for home upgrades including heat pumps, so ask what is available when you get quotes.
Temporary situation. If you rent, the grant goes to the owner, and if you plan to move soon, the upfront cost may not pay back in time.
What does the switch involve?
An outdoor unit, a hot water cylinder if you have none, larger radiators where needed and new controls. Your MCS certified installer removes the old boiler and handles the Boiler Upgrade Scheme application.
Read the detail
Replacing an electric boiler with a heat pump involves installing the outdoor unit (needs wall or garden space), connecting it to the heating system indoors, installing a hot water cylinder (if you do not have one already), upgrading radiators that are too small for heat pump flow temperatures, adding heating controls, and removing the old electric boiler.
Your MCS certified installer handles the work, including the Boiler Upgrade Scheme application. Read our radiator sizing guide to understand which radiators may need upgrading.
The Energy Saving Trust notes that electric boiler systems usually include a large hot water tank. Your installer will say whether it can stay or needs replacing with one suited to a heat pump; if you have none, one will be added.
For the full cost by property type, see our heat pump cost by house type guide. Use our heat pump calculator for a personalised estimate.
Do solar panels help?
Partly, mostly with hot water in spring and summer rather than winter heating. The median home bought 12.2% less electricity in its first year with panels, while a heat pump cuts heating electricity by about two thirds.
Read the detail
Solar panels help most with hot water in spring and summer; in winter, when the heating runs hardest, they produce far less. In homes that fitted solar panels in 2023 to 2024, the median home bought 12.2% less electricity in the first year (304 kWh), according to DESNZ NEED data. A battery can store daytime solar or cheap night electricity for the evening.
A heat pump cuts the electricity the heating needs by about two thirds, so it does far more for an electric boiler home's bill than solar panels alone.
Frequently asked questions
Is a heat pump cheaper to run than an electric boiler?
Yes, much cheaper. At the median efficiency measured in the Electrification of Heat trial, a heat pump uses about 64% less electricity for the same heat. For a 3-bed semi, an electric boiler costs about £2,606 a year to run, a heat pump £937 on a standard tariff and £666 on a heat pump tariff, a saving of about £1,940 a year. Use our calculator for your property.
How much does an electric boiler cost to run per year?
In our model, about £1,660 a year for a 2-bed terrace up to £3,460 for a 4-bed detached house at the single rate of 26.32p/kWh. Electricity costs 3.3 times as much per kWh as gas at the October to December 2026 price cap. An off-peak meter such as Economy 10 can bring the cost down if most of the heating runs in the cheap hours.
Should I replace my electric boiler with a heat pump?
If you have outdoor space for the unit, very likely. For a 3-bed semi, a heat pump costs £3,500 to £8,000 after the £7,500 Boiler Upgrade Scheme grant and saves about £1,940 a year on a heat pump tariff, a payback of about 2 to 4 years. Few heating swaps pay back faster.
What are the advantages of an electric boiler?
It costs far less to buy and fit, it is compact and silent, it needs no outdoor unit and it raises no planning questions. It makes most sense in a small flat with no outdoor space or very low heat demand.
Can I get a grant to replace an electric boiler?
Yes, in England and Wales. The Boiler Upgrade Scheme gives £7,500 towards a heat pump when you replace fossil fuel heating, and GOV.UK counts electric heating in that. ECO4 may also cover insulation until it closes on 31 December 2026. Use our grant eligibility checker.
Data sources
Running costs use the Ofgem price cap and efficiency comes from the Electrification of Heat trial, with installed costs from DESNZ Boiler Upgrade Scheme statistics and grant rules from GOV.UK.
Show every source
Running costs calculated from the Ofgem price cap, October to December 2026. Heat demand from our own model, fitted to DESNZ National Energy Efficiency Data-Framework data. Heat pump efficiency from the Electrification of Heat trial (Energy Systems Catapult for DESNZ, December 2024). Installed costs from DESNZ Boiler Upgrade Scheme statistics, August 2026. Grant rules from GOV.UK. Electric heating facts from the Energy Saving Trust (page updated 1 July 2026), and compact heat pumps for flats from its air source heat pump advice (updated 23 September 2026). Solar savings from NEED Impact of Measures 2026.