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.
So, a condensing boiler does not have to work really hard or use too much fuel for getting the water up to the temperature that is required for heating the house. Usually a gas boiler heat exchanger is fitted around the fuel that comes from the boiler for heating up main cold water that is into it. The liquid is either used as pre-heating incoming water or is stored in a tank for a later use. Contents. 1 The Heat Exchanger Repair.