Gas Central Heating & Condensing Boilers

High Efficiency Boilers are Compulsory Due to Building Regulations

Sep 24, 2009

High Efficiency (HE) is achieved by A and B rated condensing boilers these are now mandatory, with a few exceptions. A new central heating system will be cheaper to run.

Only High Efficiency (H.E.) boilers are allowed to be installed in new or existing buildings, as a result of changes to the Building Regulations for England and Wales Part L (Heating) which came in to effect in April 2006,

There are a few exemptions from this rule, there must be a full assessment and overwhelming reasons why it is not practical to install a condensing boiler.

H.E. boilers have a sedbuk rating of A or B. By default the regulations now require all new boilers to be of the condensing type in order to achieve the high efficiency levels that are stipulated.

What is a High Efficiency Boiler?

The sedbuk rating is the Seasonal Efficiency of Domestic Boilers in the UK. The public are familiar with white goods having efficiency ratings, this is similar. Sedbuk A rated boilers are at least 90% efficient and B rated are over 86%; efficiency is defined as output compared to input. In other words, an A rated boiler will convert at least 90% of the fuel within the combustion process in the boiler, whereas, an old G rated boiler is less than 70% efficient, so at least 30% of the fuel went straight out of the flue.

To upgrade from a G to an A rated boiler is likely to cut the average fuel bill by a quarter. The sedbuk website provides a list of most boilers with their rating for comparison.

What are Condensing Boilers?

The technology has been used in Europe for more than 25 years but is new to the U.K. Flue gases from a standard boiler are very hot, up to 180 degrees; a condensing boiler diverts this hot gas from the flue and reburns it. The expelled flue gases of a condensing boiler are only about 55 degrees. With the drop in temperature water vapour condenses, hence the name, this condensate liquid must be drained.

Condensing Boiler and Traditional Central Heating System?

All types of boiler are available as condensing boilers: regular, system, combination and back boiler units. A condensing boiler can be combined with a heating system which has stored hot water.

A traditional British gas central heating system has a regular boiler (sometimes called heat only) with gravity hot water and pumped heating, this system is dated and inefficient.

H.E. boilers require a fully pumped system, both heating and hot water. A traditional heating system can be adapted to be fully pumped.

System boilers have been installed in the U.K. since the 1980s after proving successful in Europe. The most common boiler to be fitted today is the combi boiler, which is suitable for smaller households and dwellings.

A new boiler must be installed by a qualified and registered engineer and a part of his or her training and experience will be to advise on the best boiler for a particular type of property and family. So ultimately when deciding on a new boiler one should consult an engineer who will visit the house.

How Much Will It Cost To Have A Replacement Boiler?

All new boiler installations must undertaken in such a way to meet expectations of best practice and a certain set of user controls must be in place to ensure the system can work efficiently. When contemplating a new boiler a few quotations should be obtained. Replacing a boiler in the average home could cost between £1,500 to £3,000 or more. The heating system shouid work as well as can be expected and will be most efficient, thereby, reducing fuel bills.

The copyright of the article Gas Central Heating & Condensing Boilers in Home Plumbing is owned by Deborah Percy. Permission to republish Gas Central Heating & Condensing Boilers in print or online must be granted by the author in writing.