How Much Electricity Does a Gas Boiler Use Per Hour

Gas boilers are often thought of as purely gas-powered appliances, but in reality, they also rely on electricity to function properly. While the majority of the energy they use comes from burning gas to produce heat, the electrical components inside the boiler are essential for safe and efficient operation. Homeowners and landlords sometimes wonder how much electricity a gas boiler uses per hour, especially when trying to calculate energy bills or when comparing the efficiency of different heating systems. Understanding this figure requires looking at how boilers work, what parts consume electricity, and how this usage compares to other household appliances.

Why Gas Boilers Use Electricity

A modern gas boiler has several electrical components that keep it working safely and effectively. The main ones include the pump, which circulates hot water around the central heating system and into radiators or underfloor heating. The fan, which pushes air and flue gases safely through the system, is another key part. Electronic ignition systems replace the old pilot light, using a small electrical spark to ignite the gas whenever the heating or hot water is needed. The printed circuit board, which is essentially the brain of the boiler, also requires a constant but very small supply of electricity to manage temperature sensors and safety cut-offs. Without these components, the boiler would not be able to run safely in line with current UK building regulations and gas safety standards.

Average Electricity Consumption per Hour

Although a gas boiler uses electricity, the amount is relatively low compared to many other appliances in the home. On average, a domestic gas boiler in the UK uses between 100 and 200 watts of electricity per hour when it is running. To put this into context, this is roughly the same as a standard light bulb or a small television. Over the course of an hour, this equates to about 0.1 to 0.2 kilowatt hours of electricity. With the average electricity price currently at 28 pence per kilowatt hour, the cost works out at between 3 pence and 6 pence per hour.

Annual Running Costs from Electricity

While gas is the main cost of running a boiler, the electrical side should not be ignored entirely. If a boiler runs for an average of 5 hours per day during the colder months, the electricity use would be around 0.5 to 1 kilowatt hour per day. Over a year, this might add up to around 150 to 300 kilowatt hours of electricity. At today’s rates, this would cost between £40 and £80 annually. This is small compared with the gas bill but still worth factoring in, especially for those trying to reduce household energy consumption.

Factors That Affect Electricity Use

Not all boilers consume electricity in exactly the same way. Older models may be less efficient and require more electricity to run their pumps and fans. A larger home with more radiators may also require a stronger pump, which increases energy use. The type of boiler makes a difference too. Combination boilers, which provide both heating and hot water directly, may use electricity more frequently than system boilers that rely on a hot water cylinder. The condition of the system also plays a role. A poorly maintained boiler with clogged filters or failing components may need to work harder and therefore use more electricity than one that has been regularly serviced.

Comparison with Other Household Appliances

When compared to larger electrical appliances, a boiler’s electricity use is relatively low. For example, an electric oven can use over 2 kilowatt hours in a single hour of cooking, while a tumble dryer may use a similar amount during a drying cycle. Even a fridge, which runs constantly, will often use more electricity overall across a year. However, because the boiler is often running for extended periods during the colder months, its electrical usage can build up. The important point is that while the boiler’s electricity consumption is not usually the main driver of energy bills, it is still a steady background cost.

Efficiency and Modern Controls

Modern boilers and heating controls are designed with efficiency in mind. Features such as variable speed pumps and smart thermostats can reduce electricity use by only running components when they are needed. A boiler with an ERP A rating will not only burn gas more efficiently but also operate its electrical parts more effectively. Smart heating systems that link to apps can also prevent unnecessary boiler use, which in turn reduces electricity demand. Regular servicing by a Gas Safe registered engineer helps to ensure that all parts are functioning correctly, preventing waste and keeping consumption to a minimum.

Environmental Considerations

The electricity a boiler uses contributes to a household’s overall carbon footprint. Although the amount is relatively small compared to the gas burned, reducing unnecessary use is still beneficial. Ensuring your heating system is properly balanced and well maintained will keep the electrical load as low as possible. If paired with renewable electricity sources, such as a green energy tariff or solar panels, the environmental impact of a boiler’s electrical consumption can be minimised even further.

Conclusion

A gas boiler in the UK typically uses between 100 and 200 watts of electricity per hour, costing around 3 to 6 pence during operation. While this is a small fraction of the overall running costs, it is important to understand that boilers are not entirely gas-powered and do rely on electricity for key functions. Keeping the system well maintained, choosing an efficient model and using modern heating controls will all help to reduce electricity use. For homeowners, landlords and tenants, knowing how much electricity a gas boiler uses per hour provides a clearer picture of household energy consumption and can inform decisions about upgrades and energy-saving measures.