29 Sep What’s a condensing boiler and how does it work?

Condensing boilers are highly efficient. They use less fuel and have lower running costs than standard boilers. Higher efficiency levels are made possible by extracting heat contained in the combustion gases, which would otherwise have been lost to the atmosphere.

This is because both oil and gas contain hydrogen locked within their chemical structure. When oil or gas is burned, the hydrogen links with oxygen in the air to form H 2 O (water). This water (as vapour) can be seen from the exhausts of cars on cold days.

The vapour (or steam) contains about 8% of the total fuel’s energy and capturing it makes energy efficiency sense. This is exactly what condensing boilers do. They “condense” the vapour and capture the energy contained there, making modern boilers so much more efficient.