Heating accounts for about 60 per cent of what you spend in a year on energy bills, so an efficient boiler makes a big difference.
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 larger heat exchanger, so it recovers more heat, sends cooler gases up the flue and is more efficient.
What should I consider when replacing my boiler?
If it is time to change your boiler, you need to decide what type of boiler is right for you. Here are some things to consider:
Most old gas and oil boilers are regular boilers that have a separate hot water cylinder to store hot water, rather than providing it directly from the boiler. When you replace your boiler you can buy a new regular boiler, and keep your hot water cylinder, or buy a combi boiler that doesn’t need a cylinder.
A regular boiler is 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. Which is better for you will depend on different things:
Your hot water usage
Large families using lots of hot water are likely to be better off with a regular boiler, whereas smaller households using less may be better off with a combi boiler.
Space in your home
Combi boilers don’t need hot water cylinders, and therefore require less space in your home.
What else can I do to improve my central heating system?
There is a wide range of heating controls available that will help your heating system work more efficiently and help keep your bills down.
Heat recovery devices and systems
Some of the heat generated by your boiler escapes through the flue. Passive flue gas heat recovery systems capture some of this lost energy and use it to heat your water, making your heating system more efficient and saving you money. They are only available for combi boilers as they provide heat to the cold water supply that is feeding the hot water output.
Some models include some heat storage, which increase the savings but usually also increases the installation cost.
Some new boilers are made with flue gas heat recovery already incorporated, so there is no need to buy a separate heat recovery device.
Hot water cylinders
New hot water cylinders are factory insulated to help keep your hot water at the right temperature for longer. They play an important role in supplying you with readily available hot water, so it’s important that they are fully insulated to prevent heat escaping.
If you have an old cylinder you could save around £20 a year by topping up the insulation to 80mm. Alternatively if you are replacing your cylinder, you can save energy by making sure that the cylinder is no bigger than you need it.