How to decide between a gas or electric boiler.

We investigate:

  • The problem with gas boilers
  • Electric vs gas boilers
  • Answers to frequently asked questions
  • Renewable energy options for your home
  • We can also help you find installers local to you

Dive in to find out more!

What’s wrong with gas boilers?

Natural gas releases carbon into the atmosphere when it’s burned. Domestic heating is believed to be responsible for around 14% of all UK emissions. The government’s net zero strategy aims to remove fossil fuels from all sectors of the UK economy, replacing them with renewable power to meet net zero carbon emissions targets by 2050.

Electric heating is gaining ground as a low carbon heating system, but while electric boilers are obviously better for the environment, electricity is more expensive than gas, making them more costly to run. Natural gas is the cheapest way to heat a home and gas central heating is installed in around 80% of UK homes, with gas boilers being the most common heating system.

According to the Energy Saving Trust, which advises householders on the best energy efficiency options, heating accounts for over half of a home’s energy bills, so getting the right boiler is important. (Energy Saving Trust, 2022). If you’re thinking of making your home more energy efficient or are embarking on a retrofitting programme, a boiler upgrade may form part of this.

A gas boiler being checked by an installer.

Electric vs gas boilers

Electric boilers

Electricity is turned into heat instead of burning fossil fuels to do this.


  • There is no risk of a carbon monoxide leak.
  • Quiet operation.
  • While an annual service is advised by a qualified heating engineer, as there are fewer moving parts, they are easier to maintain with lower repair costs.
  • There are no emissions.
  • There is no need for a flue pipe, making installation easy and cheaper.


  • Electric boilers are more costly to run as electricity is more expensive than gas.
  • They are most suited to smaller homes and flats with low heating and hot water demand and may struggle to heat a large property.
  • Most electricity is made by burning fossil fuels; however, renewable energy output is increasing.
Setting an electric boiler.

Gas boilers

Gas boilers operate by burning natural gas, generating heat for a home’s central heating system and hot water.


  • Gas boilers are cheaper to buy than electric boilers and there is a greater choice of models on the market.
  • Replacing a gas boiler with another gas boiler is straightforward and the cheapest option for homes connected to the gas network.


  • An annual boiler service is recommended by a gas safe registered engineer and moving parts may create expensive maintenance problems.
  • Gas boilers are larger than electric boilers, taking up more space.
  • There is the risk of carbon monoxide leaks.

Efficiency comparison

Electric boilers have a 99-100% efficiency rating, while gas boilers score around 93%. Electric boilers have an ErP D-rating while gas boilers have an A-rating, making it hard to compare models when deciding which to buy. (Boiler Guide, 2022).

The running cost of an electric boiler is higher, but it could save money over time. You need to consider:

  • The boiler cost – electric boilers typically cost from £1,000, gas boilers cost from £500 upwards.
  • Installation – costs depend on the boiler size, location and the installer’s charges, but vary between around £500-£2,000 for both types of boiler.
  • Running costs – an electric boiler will use half the energy of a gas boiler, but electricity is significantly more expensive than gas.
The government aims to stop the UK economy burning fossil fuels by 2050 in view of the climate change crisis.

24Housing asked Brian Horne, senior insight & analytics consultant with the Energy Saving Trust, some common questions.

Can you switch from a gas boiler to an electric boiler?

Mr Horne said: 

You could switch from a gas boiler to an electric boiler, but this would dramatically increase your heating bills. You would have to replace the boiler and add a large hot water tank to store the heat if you want to make use of cheaper off-peak electricity – this would help limit the increase in running costs, but the gas boiler would still be cheaper to run at current fuel prices. Alternatively, you could consider a heat pump – this uses electricity but will use much less than an electric boiler, so running costs would be similar to a gas system. 

Can you keep your current gas boiler and replace it when necessary? 

As part of the UK Government’s plan to reach net zero carbon emissions by 2050, fossil fuel heating systems are likely to be phased out over time. This will start with a ban on gas and oil boilers in new homes from 2025 and 600,000 heat pumps will need to be installed in homes each year by 2028. In the meantime, current gas boilers are still widely used.  

However, if you’re thinking ahead for when yours needs to be replaced, now might be the time to switch to a low or zero carbon emission heating system such as a heat pump. A heat pump captures heat from outside and moves it into your home.

It uses electricity to do this, but the heat energy delivered to your home is much more than the electrical energy used to power the system. If this is of interest, it is worth looking into the UK Government’s Boiler Upgrade Scheme for money off the installation.    

There are several things to consider when deciding what type of heating system is right for you. If you have a mains gas connection, a modern, condensing gas boiler has typically the lowest running costs to provide heating and hot water.

If you’re looking to lower your carbon emissions, you should consider a form of low carbon heating such as a heat pump, which could also reduce your running costs depending on the type of system and fuel you’re replacing. 

Gas and oil boilers are either ‘system’ or ‘regular’ boilers, which have a separate hot water cylinder to store hot water, or ‘combi’ boilers, which heat hot water on demand and don’t require a hot water cylinder. System and regular boilers are more efficient than combis at producing hot water, but heat is lost from the hot water cylinder over time.

A combi boiler could be more efficient overall, although this depends on several factors such as how many people there are in the property and whether you are likely to install solar panels in the future. Having a hot water tank allows you to store energy from a solar system – if you are not able to install solar panels then this might influence your decision. 

What should I think about when choosing my next boiler?

This depends on different things, including: 

  • Your hot water usage. Large families using lots of hot water are likely to be better off with a system boiler, whereas smaller households using less hot water may be better off with a combi boiler. 
  • Space in your home. Combi boilers don’t need hot water cylinders, and therefore require less space. 
  • Compatibility with solar water heating. If you’re thinking of installing solar water heating, it’s simpler for them to work with system boilers, although combi boilers can be adapted too. Hot water cylinders can also be used to take up surplus solar electricity generation, or to use very cheap off-peak electricity if you’re on a smart time-of-use tariff 
  • Being heat pump ready. Most heat pumps work with a hot water cylinder, so if you get rid of your existing cylinder and fit a combi boiler, keep in mind that the cylinder may need to be put back in if you switch to a heat pump in the future. 

Renewable energy alternatives to power your home

If you are considering renewable sources, investigate current grants and schemes as it is possible to receive payments via government grant schemes for renewable heating systems.

If you want to generate your own electricity, there are several alternatives, including:

Solar PV panels

These allow you to turn energy from the sun into electricity to heat your home and they can be used to power an electric boiler. Solar energy is used to heat water in a cylinder via an immersion heater which provides hot water to the household’s taps, but to get central heating from panels, a separate heating system is needed, such as a boiler, heap pump or infrared panels.

As they won’t work at night you may have to have a contract with an energy supplier, alternatively, solar energy could be stored in a solar battery. Typical costs of panels range from £3,000-£7,000.

Panels generating power from the sun.

Air and ground source heat pumps

Air and ground source heat pumps extract heat from the air or ground and use it to heat the property. Air source heat pumps can cost between £4,000-£11,000; ground source heat pumps cost from £8,000-£12,000. The high purchase costs should reduce over time, and you’ll make immediate savings on energy bills.

Ground source heat pump installation.

Biomass boilers

These burn plant-based material such as wood pellets, chips or logs, and the process warms water for central heating and taps. Biomass boilers can cost between £4,000-£21,000. (Boiler Guide, 2022)

A biomass boiler.

Infrared panels

Infrared panels are efficient, they emit radiant heat to directly warm objects and people rather than the air in a room. They are more expensive than traditional heating systems, costing £150-£500 plus per panel, but they can reduce energy bills and result in a return on investment.

There is no need for pipework so installation is simple, but space must be kept clear around the panels. They run on electricity but as they are efficient, they don’t need to be on for as long as other forms of heating. Panels come in several sizes and output ratings.

There is minimal maintenance compared to central heating systems, no risk of carbon monoxide leaking from a boiler, and running costs vary according to the price you pay for electricity, the size of panels and the wattage. (Boiler Guide, infrared heating panels, 2022)

LPG boiler

Powered by liquid petroleum gas from a tank rather than mains gas, LPG boilers work in a similar way to a standard gas boiler. They are often chosen when a house is off the gas grid. LGP boilers are made by many of the leading boiler suppliers and can cost between £500-£2,000.

LGP bottled gas.

Hydrogen boiler

These are similar to gas-powered boilers and the government aims to encourage their use gradually, initially introducing a 20% hydrogen blend into the UK mains supply. Many gas boilers sold currently are hydrogen blend-ready for the switch time, which won’t be until at least 2028. Hydrogen boilers cost the same as a gas boiler but are more environmentally friendly.

A hydrogen boiler.

Which is the best heating system for you?

If your house is connected to the gas grid, a gas boiler is probably the cheapest option as gas is cheaper than oil, LPG and Economy 7 electricity. A gas combi boiler providing heated water and central heating in one system may prove to be the best choice for many family homes.

They are efficient, compact and provide hot water and heat on demand, however, they may struggle to meet high demands for water – and a minimal amount of electricity is needed to ignite a gas flame.

A conventional gas boiler, working with a water tank and cylinder, may be a better choice for larger homes, while for smaller houses, an electric boiler could be a better option.


Boiler Guide. 2022. Electric boiler vs gas boiler. [Online]. Available from: (Accessed 9th June 2022)

Energy Saving Trust. 2022. A quick guide to boilers. [Online]. Available from: (Accessed 9th June 2022)

Boiler Guide, infrared heating panels. 2022. [Online]. Available from: (Accessed 9th June 2022)

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