Home heating systems Gas central heating
How gas central heating works
Most households in the UK have mains gas central heating. This is a so-called ‘wet system’, which means a gas-fired boiler heats water to provide central heating through radiators and hot water through the taps in your home.
Some houses that aren’t connected to the gas network can use electrical heating or liquid petroleum gas (LPG) or heating oil, which work in a similar way to gas central heating, although LPG and oil are delivered by road and stored in a tank, which you may have to buy or rent from your supplier.
Annual cost of gas
The average annual cost for heating and hot water using gas in the UK is £609 when consuming around 13,500 kWh a year.
The annual fuel cost is based on the average cost of gas per kWh across all six energy suppliers multiplied by the median usage in kWh.
Remember, this cost is just a guide to help you compare costs of different types of fuel. There are a number of factors that affect energy bills, including the age of a house and insulation, the efficiency of a hot water and heating system, and where you are in the UK.
If you're worried about your energy bills, it's worth seeing whether you're on the right energy tariff for you by using our free energy switching service, Which? Switch.
Pros of gas central heating
Gas is a highly efficient fuel, so you get a good return on every unit of energy. Modern condensing boilers, which use hot flue gases that are wasted in a standard boiler, have very high efficiency. Some are now 90% or more efficient.
Gas is piped directly to your home so you don’t need to store any fuel.
Replacing a standard gas boiler with a highly efficient modern condensing boiler is relatively straightforward. See our boiler Best Buys to find out which models come from Which? recommended brands.
As gas is the most widely used heating fuel in the UK, finding a plumber on the Gas Safe Register scheme should be fairly easy if your boiler breaks down or needs servicing. Anyone proposing to carry out work on your boiler is required by law to be on the Gas Safe Register. You can check an engineer or firm's registration on the Gas Safe Register website or by calling directly on 0800 408 5500.
Which? members can find details of plumbers in their local area that have been recommended by other Which? members at Which Local.
Cons of gas central heating
The UK is no longer self-sufficient in gas and must compete with growing demand from other countries.
Installing a gas central heating system from scratch can be expensive and disruptive. If you’re not on the gas network, connecting your property can also be costly.
Gas boilers can be serviced annually to ensure they run efficiently and last as long as they should do. See our reviews of boiler cover for more information.
As a fossil fuel, gas produces carbon dioxide when it’s burned and can’t be considered a clean source of energy.