Changing your boiler: a guide to heating and hot water
Boilers keep your home lovely and warm and your water hot, but also use up around 60% of your annual household energy bills – so an efficient boiler can make a significant difference to the amount you spend.
By replacing an old gas boiler with an A-rated high-efficiency condensing boiler – and improving your heating controls – you can significantly reduce your home's carbon dioxide emissions, and potentially save as much as £300 a year.
Should I maintain or replace my boiler?
Service your boiler every year to make sure it's safe and heating your home efficiently. If you're told it's time to buy a new one, expect a straightforward replacement to cost around £2,300, although this varies depending on the type of boiler you require, which in turn depends on your household's size and needs.
If you haven't had your boiler serviced but suspect it needs replacing, find out how old and energy-efficient it is at www.boilers.org.uk by inputting your boiler’s name and model.
A gas boiler usually offers the cheapest heating system. If you have an oil, LPG or coal boiler find out how much it would cost to get a gas supply to your home, if it's practical.
Types of boilers
In the UK, by law every new central heating boiler installed must be a condensing boiler, in both gas- and oil-heated homes. Well-maintained boilers burn fuel very efficiently, but inevitably lose some heat via the hot gases that escape up the flue. A condensing boiler has a bigger heat exchanger so recovers more heat, sending cooler gases up the flue -- and is therefore more efficient.
There are three types of condensing boilers: regular, system and combi (combination). Regular condensing boilers heat water then store it in a hot water cylinder. These are often the best choice for family-sized homes, although some heat is lost from the cylinder. System condensing boilers are suitable for similar-sized family homes, but have heating and hot water components already built in, so are easier and quicker to install.
A smaller household using less hot water may be better off with a combi boiler, combining instant hot water heating with central heating in one boiler – and since it uses water directly from the mains, it doesn’t need a cylinder – so requires less space.
A CORGI-qualified installer or Competent Persons Scheme technician can advise you on the best boiler for your household.
Energy efficient boiler controls
You can save money on household bills by making sure you have the right heating controls for your boiler and radiators. These will help you keep your home at a comfortable temperature without wasting fuel or heat.
- Install a room thermostat and you could save £70 and 280kg of carbon dioxide each year*. Set your room thermostat to be between 18-21°C.
- Fit a hot water tank thermostat and you could save £30 and 130kg of carbon dioxide each year*.
- Fit a hot water tank insulation jacket and you could save £40 and 170kg of carbon dioxide each year*.
- Turn down your room thermostat by one degree, and you could save around £55 and 230kg of carbon dioxide each year*
* Statistics from the Energy Saving Trust