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.

Efficiency ratings (non-domestic installations)

Detailed guidance on the minimum acceptable performance of heating, cooling, ventilation and hot water systems is available - you can download the non-domestic heating, cooling and ventilation compliance guide (PDF, 170K).

The guide also specifies the minimum acceptable performance of other forms of commercial heating, such as warm air, radiant and heat pump systems.

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.