Green Deal – Heating Information

Boilers account for around 60% of what you spend in a year on energy bills, so an efficient boiler makes a big difference.

Replacing an old gas boiler with an A-rated high-efficiency condensing boiler and improving your heating controls will significantly cut your home’s carbon dioxide emissions – and could save you as much as £300 a year.

Why are new boilers more efficient?

Modern boilers are more efficient for several reasons, but their main advantage is that they are all condensing boilers. All well-maintained boilers burn their fuel very efficiently, but they inevitably lose some heat in the hot gases that escape up the flue. A condensing boiler has a bigger heat exchanger, so it recovers more heat, sends cooler gases up the flue and is more efficient.

Sometimes the flue gases get so cool that the water vapour in the gas condenses out (hence the name). When this happens, even more energy is recovered from the condensing vapour, and the efficiency gets higher still.

Installing a new boiler

If it is time to change your boiler, then the first thing is to decide what type of boiler you need.

The right boiler

Most old gas and oil boilers are regular boilers – they have a separate hot water cylinder to store hot water, rather than providing it directly from the boiler. When you replace your boiler you have a choice of buying a new regular boiler, and keeping your hot water cylinder, or buying a combi boiler that doesn’t need a cylinder.

A regular boiler is actually more efficient than a combi at producing hot water in the first place, but then some heat is lost from the hot water cylinder, so a combi may be more efficient overall. The best option for you will depend on a number of factors:

How much hot water do you use? A large family using lots of hot water could be better off with a regular boiler – a smaller household using less may be better off with a combi.

Are you short of space? A combi boler doesn’t need a hot water cylinder, and so needs less space.

Are you thinking of installing solar water heating? Many combis are not compatible with solar water heating or cannot use it so effectively.

Once you’ve decided on the type of boiler, you then need to make sure that you choose the most efficient model and get it installed safely and legally. You can make sure your boiler is of the highest efficiency by choosing one of our recommended boilers: