Support
How can we help?
Help with problems with a fothermo product you already own. Here you'll find solutions to the most common faults – if nothing fits, use the support form at the bottom of the page.
Solar hybrid boiler
Hybrid boiler.
The boiler won't switch on and the display is off.
Connect the solar panels to the boiler – the display is powered by solar power and will then show the current water temperature.
If it stays off, press and hold the ON button to the right of the display for 5 seconds.
If it is still off, check the plug connections and the correct polarity of the panels. If that does not help, please use the support form.
The display gets warm or turns dark.
Important: Disconnect all live cables from the boiler and take it out of operation. The circuit board is probably faulty.
The cause is usually connecting the panels in series – even briefly. The excessive voltage damages the electronics.
Contact us via the support form and describe the cause if known (e.g. series connection). After a short analysis we can usually offer you new electronics quickly.
The water doesn't get hot although power is displayed.
A cable inside the boiler may have come loose, or the mechanical safety temperature limiter may have tripped. Please contact us via the support form – we will fix it quickly.
The solar power shown is too high, even in bad weather.
A cable inside the boiler may have come loose, the safety temperature limiter may have tripped or – rarely – the heating element may have burnt out. Please contact us via the support form.
With mains power (230 V) the water gets hotter than 65 °C.
Turn the thermostat on the boiler down, e.g. to 45 °C, and check whether the water slowly cools down. If it does, the boiler is working properly.
If it does not cool down, please contact us via the support form.
With solar power the water gets hotter than 65 °C.
Important: Disconnect all solar panels from the boiler. The circuit board is probably faulty – usually because the panels were briefly connected in series.
Contact us via the support form and describe the cause if known. We can usually offer you new electronics quickly.
The non-return and pressure relief valve is dripping. Is it broken?
No, that is normal. Especially when the water expands strongly while heating up, a little water escapes. Make sure it can drain away properly.
Solar immersion heater
Solar immersion heater.
The display is off and the solar immersion heater won't switch on.
Press and hold the ON button to the right of the display for 5 seconds.
If the display stays off, check the plug connections and the correct polarity of the panels. If that does not help, please use the support form.
The display gets warm or turns dark.
Important: Disconnect all solar panels from the solar immersion heater. The circuit board is probably faulty.
Please contact us via the support form – we will find a solution together.
The water gets hotter than the set maximum temperature.
Important: Disconnect all solar panels from the solar immersion heater. The circuit board is probably faulty. Please contact us via the support form.
Solar storage tank
Storage tank.
One or more status lights are flashing red.
Please contact us via the support form. Together we will solve the problem quickly and easily.
Support form
Didn't find a solution?
Briefly describe your problem – our support team will get back to you.
Questions before you buy? Please use our contact form.
Our support team will get back to you as soon as possible.