Save money on home energy

Replacing your home’s boiler can be an expensive and disruptive business, but if the boiler’s old, it’s well worth it.

According to the Energy Saving Trust, swapping an old boiler for an A-rated condensing one - and upgrading the heating controls at the same time - could reduce your fuel bills by up to around £300 a year and will slash your home’s CO2 emissions.

“An ageing heating system of 15 years old or more may actually be wasting as much as 30p of every pound spent on heating your home or water,” says Martyn Bridges of boiler manufacturer Worcester, Bosch Group.

“Older boilers are also likely to have a standing pilot light, which could be costing in the region of £50-£60 per year.”

In all but exceptional circumstances, new gas boilers have, by law, to be condensing ones.

They’re the most energy efficient because they recover heat from the gasses that escape through the flue.

There are different types of condensing boiler, though. Traditional-style (system or open-vent) boilers store hot water in a cylinder (usually housed in the airing cupboard), while combi boilers heat the water on demand.

With a combi, you save space and because the water is heated pretty much instantly, you don’t have to plan ahead to get hot water.

If, however, your household uses a lot of hot water and your home has multiple bathrooms, or it has low mains water pressure, a boiler with a cylinder may be more suitable. Your installer will be able to advise you.

It’s illegal for anyone other than an installer registered with Gas Safe Register to fit or work on a gas boiler.

At, you can check if an installer’s registered and find registered installers in your area.

It’s obviously best to go with an installer who’s been recommended to you, but failing that, ask for references or look for customer feedback online.

Replacing a gas boiler usually costs between around £2,000 and £3,000, including the cost of the boiler itself.

A registered installer will be able to ensure that their work complies with building regulations, as it must by law, and should provide you with a certificate when the new boiler is fitted, which you may need when you sell your home.

All gas boilers should be serviced annually - with a new boiler, this may be necessary to extend the manufacturer’s warranty.

“Even if your boiler is not that old,” says Bridges, “it is important that it has an annual inspection from a qualified engineer to make sure it is running at its most efficient.”

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