What is a high efficiency condensing boiler?

High efficiency condensing boilers convert more than 88% of their fuel into heat, compared to 78% for conventional types.

A high efficiency condensing boiler works on the principle of recovering as much as possible of the waste heat which is normally rejected to the atmosphere from the flue of a conventional (non-condensing) boiler.
 

This is accomplished by using an extra-large heat exchanger or sometimes two heat exchangers within the boiler which maximises heat transfer from the burner as well as recovering useful heat which would normally be lost with the flue gases. When in condensing mode (for condensing boilers do not condense all the time) the flue gases give up their 'latent heat' which is then recovered by the heat exchanger within the boiler. As a result the temperature of the gases exiting the flue of a condensing boiler is typically 50-60°C compared with 120-180°C in a current non-condensing boiler. At the same time an amount of water or 'condensate' is produced.
 

A condensing boiler will always have a better operating efficiency than a conventional non-condensing one, due to its larger and more efficient heat exchanger.
 

Is your boiler energy efficient? If it's 10-15 years old then it probably isn't. Replacing your old boiler  with a new high efficiency condensing boiler will save you around a third on your heating bills straight away. 
 

If you're fitting a new kitchen or bathroom, why not minimise cost and disruption by installing a new high efficiency condensing boiler at the same time?

By law most new gas boilers fitted in England and Wales must now be high efficiency condensing boilers (with a few exceptions depending on suitability). High efficiency condensing boilers can be easily fitted to most new and old heating systems, ask your installer for more details.

And that's not all... If you install the right heating controls, you could save up to 40% on your fuel bill - that's about £190 - £240 off the average bill.

Did you know?

If everyone in the UK with gas central heating installed a high efficiency boiler, we would save enough energy to heat 3.7 million homes for a year. 

Condensing boilers

Condensing potterton boilers are not new, they have been around for many years and users report very significant reductions in fuel costs. This is possible, because the condensing type of worcester bosch boiler has a much more effective 'heat exchanger' allowing more heat to be removed from the flue products.

One of the most significant effects of this is the 'pluming', sometimes mistaken for 'steam' coming out of the flue terminal. This effect is brought about by water droplets held in suspension in the flue products and although non-hazardous, it may be a nuisance if seen constantly passing across windows. This pluming will be evident for most of the time the condensing boiler is operating, so care is needed in positioning the terminal.

Although condensing boilers have a somewhat higher capital cost than non-condensing boilers, for larger dwellings (with three or more bedrooms) they usually prove to be cost effective within several years.

Typically, a condensing potterton gas boiler might have a seasonal efficiency of around 88% compared to non-condensing boiler of about 75%, and an older type boiler at between 55% -60%.

Condensing worcester boilers are as easy to install as any non-condensing boiler, but can only be fitted to 'fully pumped' systems. During it's operation, condensate forms and, although no more acidic than rain fall, a permanent pipe must be run to a drain.

Condensing boilers are available as a wall mounted or floor standing version.

 

Combination Boilers (Worcester Bosch combi boilers, Potterton combi boiler)

Most wet central heating systems use a boiler to heat a copper cylinder in the airing cupboard to provide stored domestic hot water. A combination boiler (usually referred to as a 'combi' ) provides a means of generating instant hot water for the taps from within the unit and combines this with central heating.

By using a 'combi' neither a hot water cylinder, nor it's feed tank, are required. Consequently, hot water running costs will be reduced very slightly since there are no standing losses from the cylinder or combination boiler pipework. Although a continuous flow of hot water is constantly available from a combination boiler, the flow rate is not likely to be as good as with a traditional storage cylinder, particularly in Winter.

In dwellings (often larger type) where a number of draw-off points (taps, showers etc) are likely to be used at the same time manufacturers advice should be sought as to the combi's suitability. Showers fitted to a combination boiler must be a 'mains pressure' type.

Because the combination potterton boiler is fed directly with mains cold water, it is vital to establish that the minimum water pressure, specified by the manufacturer, is available otherwise the hot water performance will suffer.

Combination boilers are by far the most popular worcester boiler type, accounting for over 50% of all new boiler sales within the UK.

A combi (instantaneous) boiler is the most widely used type of combination boiler and directly heats incoming mains cold water to supply hot water to taps, showers and other draw off points.

A combi (instantaneous condensing) combination boiler operates in principle as an 'instantaneous' type but at somewhat higher efficiencies 

Radiators (central heating radiators, radiator covers, towel radiators, designer radiators)

Radiator 'heat emitters' can come in all shapes, sizes and forms. The most common central heating radiator is the steel panel type radiator and they are available in a very wide range of sizes and styles intended to match as closely as possible individual room needs.

Aluminium radiators are becoming increasingly popular, whilst the use of cast iron radiators is also on the increase where the intention is to blend with existing traditional decoration. Towel radiators are most often used in bathrooms and WC's where the towel radiator can be used to store towels as well as heat  the room as a bathroom radiator. Designer radiators are more money but designer radiators can make a design statement and be a feature in a room. You may decide to cover up a radiator with a radiator cover, this may be because the radiator is old or unsightly. Radiator covers come in many designs to suit your room decor and most radiator covers are made from mdf. Some radiator covers can be painted in your own colour scheme.

Radiators need to be matched to the room size and also how the room will be used to ensure the correct temperature can be maintained. How the house is insulated, including double glazing, can alter how efficient the radiators are at warming a house.

Worcester Bosch boilers Potterton Boilers Central heating boilers and radiators