An indirectly heated water heater that can be used in combination with heat pumps. A water heater specially developed for combination with heat pumps. The large surface area of the heating coils and their innovative Diabolo shape guarantee very efficient potable hot water production. This results in a short heat up time and guaranteed hot water performance. - Maximum working pressure: 10 bar (potable water vessel) / 40 bar (heating coil). - Maximum working temperature: 95 °C (potable water vessel) / 110 °C (heating coil).