Boilers Explained

Condensing boilers

All new boilers installed in the UK must now be condensing boilers, except in exceptional circumstances. This is because condensing boilers are far more energy efficient than older types, improving efficiency to over 90% in many cases.

You can choose from various different types of boiler when looking for the right condensing model.

• How condensing boilers work
• Advantages of condensing boilers
• Disadvantages of condensing boilers

How condensing boilers work

There are three main types of condensing boilers: regular, system boilers and combi boilers. All have one thing in common; the ability to extract heat from otherwise wasted flue gasses.

Traditional boilers usually have a single combustion chamber and expel hot waste gasses through the flue at the top of the boiler at around 180°C.

Condensing boilers however, have a larger or even a second heat exchanger, and gasses are finally released at only around 55°C, wasting far less energy.

After that, the way that your condensing boiler works will depend on whether or not it is a combi, system or a regular boiler.

Advantages of condensing boilers

• Far more energy efficient - up to 90% in some cases
• Reduced energy bills - save up to £130 a year by replacing your boiler according to the Energy Saving Trust
• Conforms to new law stating that all new boilers or heating systems must be condensing boilers

Disadvantages of condensing boilers

• Higher purchase cost than non-condensing boilers - but energy bill savings can pay this back in a few years depending on how you use it
• “Pluming” water droplets from the flue can be a nuisance if the condensation interferes with windows