The CE mark, or formerly EC mark, is a mandatory conformity marking for certain products sold within the European Economic Area (EEA) since 1985. The CE marking is also found on products sold outside the EEA that are manufactured in, or designed to be sold in, the EEA.
Condensing boilers are water heaters fueled by gas or oil. They achieve high efficiency (typically greater than 90% on the higher heating value) by condensing water vapour in the exhaust gases and so recovering its latent heat of vaporisation, which would otherwise have been wasted.
How does a condensing boiler work? Condensing Boiler. This is a design of boiler which can have an increased efficiency over the more traditional boiler. The efficiency of a typical non-condensing boiler is around 75%, whereas with condensing boilers it can be over 87%.