How to Fix / Troubleshooting

Safety first: No water disassembly is required; only programming and possibly board replacement.

Set correct time: Enter the time-setting mode and set the current time and regeneration time. Confirm AM/PM or 24-hour format is correct.
Check after power loss: Unplug the unit for 10 minutes, then reconnect. If the time resets to default, the backup circuit is faulty.
Use metered mode: If available, switch to metered (demand) regeneration rather than strictly time-based, as a workaround.
Replace PCB: If the clock cannot retain time or E11 persists, replace the control PCB or full head assembly.

E11 error and unit skips scheduled regeneration cycles

Possible Causes