This immersion heater was specially developed for use with our photovoltaic power manager AC•THOR (3 kW) and AC•THOR 9s (9 kW) and can be installed in hot water boilers and storage tanks. Due the special design there are only very low thermal surface loads of the heating elements, which directly contributes to increase the life-span of the product. A safety temperature limiter is integrated. The desired hot water temperature can be set with a rotary knob.