Display shows anti-legionella / disinfection fault, scheduled high-temperature cycle not completed
Safety Warning
This repair may involve working with high voltage components or water connections. Always unplug the appliance before removing any panels.
If you are not confident in your ability to perform this repair safely, we strongly recommend contacting a professional technician.
Possible Causes
How to Fix / Troubleshooting
Safety first: High-temperature cycles can cause scalding. Ensure mixing valves are correctly set.
Step-by-step checks:
- Check settings: Enter the installer or advanced menu and verify that the anti-legionella function is enabled with appropriate target temperature and duration.
- Verify burner operation: During the scheduled cycle, confirm that the burner runs continuously and that the cylinder temperature is rising.
- Insulate pipework: Ensure hot water pipes near the cylinder are insulated to reduce heat loss.
When to call a professional: If the unit cannot reach the required temperature or the sensor is inaccurate, professional diagnosis is required.
Repair Difficulty
Required Part
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