Boiler shows A30, internal clock or scheduling not working

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

Depleted backup battery on Herz control board, firmware bug, power interruptions, incorrect time settings

Safety: Isolate power before removing the front panel.

Reset time: Enter the user menu and set the correct time and date. Check if the schedule now operates correctly.
Check after power loss: Turn power off for a few minutes and back on. If time resets, the backup battery is likely depleted.
Replace battery/PCB: On some Herz boards the battery is not user-replaceable; the entire PCB may need replacement by a technician.

Medium 3/5

Herz main control PCB

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