How Does a Condensing Boiler Work?

Most households in the UK now have condensing boilers fitted, but most people have no idea how they work, or why they’re so efficient. Since it’s an important part of your home and a big investment we thought that it’d be good to put together a simple explanation what makes them tick.

Condensing (condenser) boilers are a very efficient way to heat your home and provide you with hot water. The way they burn fuel means that they operate at more than 90% efficiency.

Because they are so efficient, all new boilers fitted since 2005, by law, have to be condensing boilers, where technically possible of course.

While they are simple to run and come in a wide variety of power outputs and fuel types, the way they burn fuel is actually much more sophisticated than in a conventional boiler where the fuel is simply burnt and used to heat water for the central heating. In a conventional boiler the waste gases, the byproducts of combustion, are just released through the exhaust system.

But in a condensing boiler, the heat from these exhaust gases is captured and used to add heat to the system rather than just being released. This dramatically reduces the wasted heat and improves the boilers efficiency.

One of the elements in the fuel your boiler uses is hydrogen, which you may remember from school chemistry lessons when burnt turns into water. In a conventional boiler, this water is released through the exhaust system as steam.

A condensing boiler extracts additional heat from this steam which is cooled down, or condensed, to become liquid again, recovering its energy - called its latent heat. This latent heat is used to add heat to the water for the central heating capturing a lot of the energy which would have been wasted in a conventional boiler.

Because the heat isn’t lost, the potential increase in efficiency can be as much as 10-12%, which can save you a lot of money over a few years.

While the effectiveness of this condensing process varies for each boiler and each home, a condensing boiler is always at least as efficient as a conventional boiler.

It is worth remembering that to maintain this efficiency, condensing boilers need to be serviced regularly so if you haven’t had yours serviced in a while you can talk to us about our servicing packages, just call 0800 0647 040.

Carillion Energy Services install around 30,000 central heating and boiler systems a year, many of which are on behalf of government initiatives, making it the 2nd largest heating installer in the UK. We are a national company with locally based sales consultants, installation engineers and after sales support. Further information can be found on the Carillion Energy Services website http://heating.carillionenergy.com/condensing-boilers