Condensing boilers are highly efficient. They use less fuel and have lower running costs than other 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 H2O (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.
If you have a boiler older than 15 years then it is most likely during the next few years that you will have to replace it on reliability grounds in any case. Change it now and start saving immediately.
So, replacing old boilers makes good sense for two reasons:
Significant fuel cost savings with can only increase as energy prices escalate.
Improved reliability and safety.
Increasing the operational efficiency of your boiler by this amount represents an actual fuel saving of more than 25%.
In other words, by replacing an older, low efficiency boiler with a new, high efficiency boiler, you can cut your fuel bills by a quarter