What a gas boiler really costs to run

A typical year's gas

Ofgem's typical figure for a home is 9,500 kWh of gas a year. Your own use may be higher or lower.

The typical results below show the most a home using that much could be charged, by region.

From Chris's work as a heat networks and energy manager: I’d start with the heating times, room thermostat and radiator controls. Make sure they suit how the home is actually used. On a combi, lowering the heating flow temperature while keeping the rooms comfortable can also help; where there’s a hot water cylinder, the temperature requirements need checking separately.

How the price cap sets the most you can be charged

Ofgem's price cap formula has two parts: a yearly standing charge part, plus a per-unit part for the gas you use. Then VAT is added, at 5%.

In Ofgem's North West region, paying by direct debit, the cap's maximum gas unit rate is 7.86p per kWh, including VAT.

The standing charge

In Ofgem's North West region, paying by direct debit, the cap's maximum gas standing charge is about £110 a year, including VAT. Our figures show it separately from the cost of the gas.

From Chris's work as a heat networks and energy manager: Where your tariff has a standing charge, using less gas doesn’t reduce that part of the bill. Fitting a heat pump won’t automatically remove it either if you’re keeping gas for cooking. I’d only include that saving once the supplier has confirmed the arrangements for closing the gas account and removing the meter.

Region and how you pay

The cap is set for each region and each way of paying, so the most you can be charged depends on both.

The typical results below show every region for direct debit. Open “Figures if you pay by standard credit or prepayment” for the other ways of paying.

Turning gas into heat

DESNZ assumes a modern condensing boiler turns about 84% of gas into heat in homes, based on Energy Saving Trust field trials. Source: DESNZ, 2024.

The gas costs on this page are for all the gas a home uses, so they don't change with the boiler's efficiency.

From Chris's work as a heat networks and energy manager: A modern boiler can work well, but its efficiency on paper doesn’t tell you how the whole heating system performs. High return temperatures, constant stopping and starting, poor controls and dirty system water can all drag it down. My starting point is to understand how the system is operating before deciding the boiler needs replacing.