Understanding boiler efficiency ratings (SEDBUK)

New regulations introduced by the UK Government in 2010 state that every new boiler installed in a property must have an energy efficiency rating of at least 88%.

Boilers with a higher efficiency rating produce less CO2 emissions and reduce your energy usage. This is good for the environment and great for your bills.

Despite the 2010 regulations, estimates suggest the average boiler efficiency rating in the country stands at 60%. The Heating and Hotwater Industry Council (HHIC) believes there are up to 9 million inefficient appliances still installed in properties, some of which are more than 20-years-old: so called ‘zombie-boilers’.

How is boiler efficiency measured?

Boiler efficiency is calculated using the Seasonal Efficiency of Domestic Boilers in the UK (SEDBUK) system. The SEDBUK system takes a number of factors into consideration, including a boiler’s energy usage when its converting fuel to heat, and other features specific to the weather and buildings of a UK region.

SEDBUK is a part of the Standard Assessment Procedure for Energy Rating of Dwellings (SAP). It was first created in 2005 by the UK government which consulted with manufacturers. During the initial years of the ‘Energy Efficiency Best Practice Programme’ boilers were given a rating of between A – G.

However this changed in 2009 to prevent confusion with the EU’s energy rating system. Now boilers given a percentage efficiency rating:

  • 90% and above – A
  • 86 – 90% – B
  • 82 – 86% – C
  • 78 – 82% – D
  • 74 – 78% – E
  • 70 – 74 – F
  • Below 70% – G

If you would like to find out the efficiency rating of your appliance, you can check the manufacturer’s manual or consult a boiler professional.

How to maintain the efficiency of your boiler

Boiler efficiency declines overtime, however, booking an annual service with a Gas Safe or OFTEC accredited engineer can go a long way to maintaining efficiency and increasing its lifespan.

Additionally, there are a number of measures you can take which will help keep your appliance in good shape.

For free advice about boilers or central heating systems, call us on 0800 311 8990 or complete our no-obligation quote form for a quick reply.