What is a condensing boiler?
Conventional boilers emit hot exhaust gases from the flue when they are operating. Some atmospheric (open flue) boilers are incredibly inefficient, with only just over half the gas burnt being put to practical use. The rest of the heat is vented outside. A condensing boiler transfers more of this otherwise wasted heat to the water in the boiler, before it reaches the flue outlet. An excellent idea, which saves on fuel use and therefore operating costs. During normal operation, condensing boilers lower the temperature of their exhaust gases below 100 degrees, and plumes of water vapour can be seen coming from the flue outside. Compared to older less efficient boilers, the flue gases are more dense, meaning they do not rise skywards as quickly. For this reason condensing boiler flues should be sited sensitively. Whilst there are gas consumption savings to be made from a condensing boiler, their actual efficiency is dependent upon the system design of the heating circuit. A condensing boi
