How to choose an efficient boiler

It is particularly important to make sure that your heating system is efficient, as heating and hot water account for 84% of the energy consumed (in a gas heated house), the remaining 16% being for lighting and applicances.

Most houses in the Stafford area, apart from the rural areas, are heated by mains gas central heating. If your gas boiler is 10 – 15 years old (or older), or your house has a different heating system, the advice on this page will help you to decide how to improve the energy efficiency of your heating system and save money on your fuel bills.

How much will I save?

If your property has access to mains gas, the most energy efficient heating system without considering renewable energy is a high efficiency condensing boiler with good heating controls. Replacing an old boiler with a condensing one can save up to a third on your heating bills and at least 875 kg of carbon dioxide a year. If you are changing to gas from oil, solid fuel or electric heating, the savings could be even greater.  The Energy Saving Trust gives more details on costs, savings and payback times. If everyone in the UK with gas central heating installed a high efficiency condensing boiler, we would save enough energy to heat 3.7 million homes for a year.

Compare condensing boilers

All new boilers are condensing boilers, which are particularly efficient as they recover heat which would be lost through the flue of conventional boilers. However the efficiency of condensing boilers varies, and it is worth paying a small amount extra for an A-rated boiler with an energy saving recommended logo, which will be more than 90% efficient. Compare different boilers at www.boilers.org.uk
Gas installers must be registered on the Gas Safe Register. This replaces the CORGI register.

Important points:

  • Condensing boilers can be fitted to most existing central heating systems, although you may need some changes in pipework, new radiators and improved controls, depending on the type and condition of the existing system.
  • The efficiency of the boiler is reduced if it is working at reduced capacity, for example if it is only being used for hot water in the summer, but it is still very efficient.
  • A plume of water vapour can be seen coming out of the wall-mounted flue.
  • Condensing boilers have a small drain pipe which needs to discharge into a drain.
  • Consider replacing your boiler when having other major work done, for example a replacement kitchen or bathroom, to minimise disruption.

There are two main types of gas condensing boilers:

  • Regular condensing boilers which provide hot water via a separate storage tank or cylinder, usually in an airing cupboard.
  • Condensing combi (combination) boilers which provide instant hot water directly from the boiler.

Advantages of regular condensing boilers

  • More suitable for larger properties with regular and simultaneous demands for hot water in different locations.
  • More suitable for the addition of solar water heating systems.
  • More suitable if your water pressure is low.

Advantages of condensing combi-boilers

  • More suitable for smaller properties where there may be less simultaneous demands for hot water.
  • More suitable for smaller properties as they save space as they don’t need a hot water cylinder or cold water feed cistern.
  • Incoming water pressure must be adequate.