Your boiler probably uses more energy than the rest of your appliances added together, but you could be wasting as much as £500 a year if it's not running efficiently.
Gas boilers are the main source of heating in most UK homes, according to comparison firm Uswitch, with 23m families relying on one for their hot water all year round and heating in the winter months. However a lot of these boilers may not be running as well as they could be, especially older models.
Boilers with top energy-saving level A are more than 90% efficient, but it's a different story for the lowest G-rated models, which can waste 40% of the money you spend on gas. A boiler normally accounts for more than half of the yearly energy bill for any home, according to the Energy Saving Trust charity, so assuming a home is capped at the £2,500 annual Government's Energy Price Guarantee level, that means running a boiler costs around £1,250. The least efficient boilers waste 40% - or £500 - of that money.
