Indirectly heated storage tanks for the production and store of domestic hot water, usually the heat exchanger is normally hydraulically connected to a boiler, a heated buffer tank or a solar system. The tank has a cleaning flange on which it can be made the periodic maintenance, and the heating element can also be found here for certain types. The internal protection of the tank is provided by a ceramic enamel coating (glass-lined at 830-850°C).
Rigid polyurethane foam insulation provides a solution to minimize heat loss. About cathode protection in storage magnesium anode is provided.

The internal heat exchanger of these tanks is fixed (welded) coil which are enamelled together with the tank. Electric heating element can be fitted to the tank, but the tank can be ordered with an electric heating element built into the flange. The maximum permissible operating pressure of the tank is 6 bar, the heat exchanger can be used with a maximum pressure of 8 bar. Its maximum operating temperature is 95°C.