Smart Heating

Hot water at all times with an intelligent reheating system. In addition to photovoltaic modules, all fothermo water heaters can also be supplied with power by an external power supply unit. This guarantees hot water even during the darkest rainy days.

The additional heating is OPTIONAL and not necessary.

fothermo power supply unit

Connecting the power supply unit

Simple, fast and effective! Connected in less than 10 seconds. 

Reheat with 230 volt power supply. Just plug in the power supply unit and the intelligent reheating is activated. 
As soon as the water temperature falls below a self-defined limit and the power of the PV module is low, the water will be reheated.

The Power Supply Unit reheats the photovoltaic water heater in times of bad weather.

Set the minimal water temperature

By setting the minimum temperature, you determine the balance between comfort and amount of directly used photovoltaic energy.

When the power supply unit is connected, the set minimum water temperature ensures that the water is permanently heated to this temperature, even if there is no PV power. The PV power always has priority over power from the power supply unit, even if the water temperature falls below the minimum. The recommended minimum water temperature is about 35 °C. 

The lower the minimum water temperature is set, the more photovoltaic energy can typically be used.

Heating duration of the power supply units

The water is only reheated when it is really needed. The water heater recognizes when there is insufficient solar power available and then activates the additional heating. This saves money and protects the environment.

The following are the heating times.

Start temperature 15 °C – End temperature 35 °C

fothermo power supply unit

External Power Supply Unit

for reheating the water during bad weather