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 a Hot Water or Steam Boiler Works. Hot water or steam boilers use a gas or oil fueled boiler to heat water and circulate the water or steam through pipes to radiators, radiant baseboards or piping in floors and walls to warm a home. The system works in the following way.