How to use heating and hot water systems efficiently

Checking boiler efficiency


Heating engineers checking commercial and domestic boiler efficiency can get useful information from several sources, including the:

  • Seasonal Efficiency of Domestic Boilers in the UK (SEDBUK) boiler efficiency database
  • Council of Registered Gas Installers
  • Institute of Domestic Heating and Environmental Engineers (IDHEE)
  • Heating and Ventilating Contractors Association

Efficiency ratings (domestic installations)

The energy efficiency of boilers intended for domestic use is rated in bands:

  • A - 90 per cent and above
  • B - 86-90 per cent
  • C - 82-86 per cent
  • D - 78-82 per cent
  • E - 74-78 per cent
  • F - 70-74 per cent
  • G - below 70 per cent

Boiler efficiency database (domestic installations)

To check the efficiency of a particular model of domestic boiler, you can consult the boiler efficiency database. This contains efficiency data for current boiler models, and is updated monthly.

Boiler checklists

Step-by-step checklists for monitoring boiler energy efficiency are available online for:

Gas boilers and space heaters below 100 kilowatts should be assessed every four years. Oil-fired or solid-fuel boilers, and space heaters larger than 100 kilowatts, should be assessed every two years.

Energy Performance Certificates

Boiler efficiency forms part of a building's overall energy performance, which must be displayed in the form of an Energy Performance Certificate.