User manual
42
741.011 | 12.18
EN
15  Troubleshooting
   Danger
Risk of death by electrocution! 
• Immediately disconnect the device from the mains supply when it can no longer be 
operated safely, e.g. in the case of visible damage. 
• Disconnect the device from the mains power before opening the case.
• All work on an open device must be performed by professional personnel. 
   Notes
The controller is a quality product, conceived for years of continuous trouble-free opera-
tion. Observe the following points:
• Faults are often caused by connected components and not by the controller. 
• The following notes on fault identification indicate the most common causes of faults.
• Only return the controller when you are absolutely sure that none of the problems 
listed below is responsible for the fault.
15.1  General faults
Display Possible cause Remedy
Controller not functioning at all
Display empty/
dark
Controller power supply is interrupted. • Check the controller power 
cable.
• Check the fuse for the power 
supply.
Controller constantly displays 12:00
12 flashes. Controller power supply was interrupted 
for longer than 15 minutes.
Set the time.
Solar circuit pump not operating + switch-on condition is fulfilled
Pump power supply is interrupted. Check the pump power cable.
Pump has seized up. Get the pump working again, 
replace if necessary.
• The maximum storage tank tempera-
ture has been reached.
• The maximum collector temperature 
has been reached.
• In multi storage tank systems: The sys-
tem has stopped due to a priority test.
• The minimum collector temperature 
has not been reached.
• The maximum loading temperature 
has been reached.
• Stagnation reduction is activated and is 
actively intervening in the control process.
• The storage tank has been deactivated 
in the priority settings.
No fault
 flashes
Pump has been switched off in manual 
mode (off)
• No fault
• Switch to automatic mode if 
necessary.










