If you are weighing up a new heating system in 2026, the single biggest question is whether to stick with gas or switch to an electric boiler. The answer hinges on running costs, which have shifted significantly in the last year.
Gas boilers are cheaper to run than electric boilers in 2026: 6.7p per kWh of heat versus 24.5p for electric. That makes gas about 3.7 times more cost-effective per unit, though the gap is narrowing.
- Gas boilers cost 6.7p per kWh of delivered heat in 2026.
- Electric boilers cost 24.5p per kWh of delivered heat in 2026.
- Gas is about 3.7 times cheaper per unit of heat than electric.
- Electric boilers run at 100% efficiency, gas boilers at 90%.
- Without mains gas, an electric boiler can be more cost-effective.
- The single most important thing to know about electric vs gas boiler running costs in 2026
- How the 2026 energy price cap sets the cost per kWh for gas and electricity
- The real annual running cost difference for a typical 3-bedroom home
- Quick numbers – annual running cost comparison table
- When an electric boiler can still be the cheaper choice despite higher running costs
- The direct answer to "electric vs gas boiler – which should I choose?" (featured snippet target)
- How to verify your installer and ensure a compliant installation
- The hidden trade-offs that make the decision more than just running costs
Gas boilers remain substantially cheaper to run per unit of heat than electric boilers, even after the latest price cap changes. However, the total annual cost gap is narrowing, and for some homes without mains gas, an electric boiler can already be the more sensible financial choice.
The single most important thing to know about electric vs gas boiler running costs in 2026
Gas boilers are still cheaper to run than electric boilers in 2026, but the difference is smaller than it was five years ago. The key reason is the ratio between gas and electricity prices, which is currently around 3.7 to 1. Because electric boilers convert all their input energy into heat (100% efficiency), while a typical gas boiler loses some heat through its flue (averaging 90% efficiency), the effective cost per unit of delivered heat is 24.5p for electricity versus 6.7p for gas. That means gas is about 3.7 times cheaper per unit of heat.
This section will give you the exact running cost figures and explain the trade-offs that determine which option saves you money over time.
How the 2026 energy price cap sets the cost per kWh for gas and electricity
The January 2026 energy price cap from Ofgem sets a typical unit rate of 24.5p per kWh for electricity and 6.0p per kWh for gas (Ofgem, 2026). These are the standard rates for a household paying by direct debit on a default tariff.
Electric boilers operate at 100% efficiency, meaning 1 kWh of electricity in gives you 1 kWh of heat out. Gas boilers average around 90% efficiency, so 1 kWh of gas produces about 0.9 kWh of usable heat (Energy Saving Trust, 2026). This means the effective cost for 1 kWh of delivered heat is 24.5p for an electric boiler and 6.7p for a gas boiler (6.0p divided by 0.90).
The ratio of electricity to gas cost is roughly 3.7 to 1, which means gas is still significantly cheaper per unit of heat. This ratio is the single most important number in your decision.
The real annual running cost difference for a typical 3-bedroom home
A typical UK three-bedroom home uses around 12,000 kWh of heat per year, according to DESNZ data (DESNZ, 2026). Applying the costs from the price cap gives the following annual figures.
A gas boiler running at 90% efficiency would cost 12,000 kWh multiplied by 6.7p, which equals £804 per year. An electric boiler operating at 100% efficiency would cost 12,000 kWh multiplied by 24.5p, which equals £2,940 per year. The annual saving with gas is approximately £2,136.
This is a large difference, but it does not include installation costs, maintenance, or future price trends. For a home with lower heat demand, the gap shrinks considerably.
Quick numbers – annual running cost comparison table
| Boiler type | Efficiency | Cost per kWh heat | Annual cost (12,000 kWh) | Annual cost (8,000 kWh small home) | Annual cost (18,000 kWh large home) |
|---|---|---|---|---|---|
| Gas boiler | 90% | 6.7p | £804 | £536 | £1,206 |
| Electric boiler | 100% | 24.5p | £2,940 | £1,960 | £4,410 |
| Heat pump (context) | 300% | 8.2p | £980 | £653 | £1,470 |
Efficiency data from Energy Saving Trust (Energy Saving Trust, 2026). Typical heat usage from DESNZ (DESNZ, 2026). The heat pump row is included for context only and is not the focus of this comparison.
When an electric boiler can still be the cheaper choice despite higher running costs
Electric boiler installation typically costs between £1,500 and £2,500, compared to £2,500 to £4,000 for a gas boiler (Checkatrade, 2026; Gas Safe Register, 2026). You also avoid the annual gas safety check, which costs £80 to £120, and the daily gas supply standing charge of around 25p per day (Ofgem, 2026).
If your home is off the gas grid, you have no mains gas connection. In that case, an electric boiler avoids the cost of installing an oil or LPG system, which can be more expensive to run than gas. For a home with very low heat demand, such as a well-insulated flat using only 4,000 kWh per year, the annual running cost gap shrinks to about £700. When you factor in the lower installation cost, an electric boiler can be the cheaper option over five to ten years.
For homes with solar panels and a battery, the running cost of an electric boiler can be reduced further by using self-generated electricity during daylight hours. This is not a factor for gas boilers.
The direct answer to “electric vs gas boiler – which should I choose?” (featured snippet target)
Choose a gas boiler if you have mains gas and a typical or high heat demand. You will save between £1,500 and £2,500 per year on running costs compared to an electric boiler.
Choose an electric boiler if you have no gas connection, a low heat demand (under 6,000 kWh per year), or if you plan to pair it with solar panels and a battery to offset running costs.
For most UK homes on the gas grid, gas remains the cheaper option in 2026. However, the gap is narrowing, and electric may become competitive if gas prices rise faster than electricity prices in future years.
How to verify your installer and ensure a compliant installation
For a gas boiler, you must use a Gas Safe Register engineer. You can check their registration number on the Gas Safe Register website before any work begins (Gas Safe Register, 2026).
For an electric boiler, the installation must be carried out by a qualified electrician registered with a competent person scheme such as NICEIC or NAPIT (NICEIC, 2026; NAPT, 2026).
Check the manufacturer’s warranty requirements before you buy. Some manufacturers demand MCS certification for heat pumps but not for electric boilers (MCS, 2026). Always get at least three quotes and verify the installer’s registration number on the relevant register before paying a deposit.
gas boiler installation checklist
The hidden trade-offs that make the decision more than just running costs
Electric boilers have lower carbon emissions if your electricity comes from renewable sources. The grid average carbon intensity in 2026 is about 0.2 kg CO2 per kWh, which is similar to the 0.2 kg CO2 per kWh from a gas boiler (DESNZ, 2026). As the grid gets cleaner, electric boilers will become the lower-carbon option.
The government’s 2026 Boiler Upgrade Scheme (BUS) does not cover electric boilers. It only provides grants for heat pumps and biomass boilers (GOV.UK, 2026). This means you cannot claim a grant to help with the installation cost of an electric boiler.
Electric boilers are smaller and quieter than gas boilers. They have no flue or condensate pipe, which can make installation simpler in a flat or a small home where external wall space is limited.
Future policy is worth noting. The UK’s 2026 Heat and Buildings Strategy indicates a phase-out of new gas boiler installations from 2035, but this does not affect existing homes yet (DESNZ, 2026). If you install a gas boiler now, it will be legal to use it for its full lifespan.
heat pump running cost comparison
Frequently Asked Questions
Yes, gas is cheaper. According to Ofgem's January 2026 price cap, gas costs 6.7p per kWh of delivered heat versus 24.5p for electricity, making gas about 3.7 times cheaper per unit.
At 24.5p per kWh and 100% efficiency, a 10 kW electric boiler costs about £2.45 per hour to run. Actual costs vary with your boiler size and usage.
A 10 kW gas boiler at 90% efficiency costs roughly £0.67 per hour of heat output. This is based on the 6.0p per kWh gas rate from the 2026 price cap.
Gas boilers are cheaper to run than electric boilers in 2026. The Energy Saving Trust confirms gas delivers heat at 6.7p per kWh versus 24.5p for electric, a significant difference.
Yes, an electric boiler can be sensible without mains gas. While running costs are higher, installation is simpler and avoids the expense of an oil tank or LPG delivery.
