Heeaters WJ are pressure vessels with shells made of steel coated inside with special ceramic enamel, which form a glassy coating protects against corrosion and ensures a good quality of heating water. Additional corrosion protection of the tank is a magnesium anode,  operation of which is based on the differences of electrochemical potentials of the material tank and the anode. Magnesium anode in heaters located in the bottom plate. The insulation of the tank is a layer of polystyrene foam entirely sheltered housing made of thin sheet metal covered with powder paint. Thanks to modern solutions design and technological WJ-type heaters are economical, durable and safe in operation, as well as easy to install and use. They can be installed in every room, which is supplied water supply network and electrical system, except for explosive premises or exposed to temperatures below 0°C.