Display shows E01 and the unit does not start regeneration

Safety first: Disconnect the unit from mains power and close the main water shutoff before opening any connections.

• Check house water supply: Ensure the main water valve and any local shutoff valves before the Grünbeck softener (often ball valves) are fully open.
• Inspect inlet hose: Look for kinks or crushing on the flexible hose connected to the softener's inlet. Straighten or replace if damaged.
• Clean inlet strainer: Many Grünbeck softeners (e.g. softliQ, Delta series) have a fine mesh strainer at the inlet. Close the inlet valve, unscrew the union, remove the strainer and rinse under running water. Reinstall carefully with the seal seated correctly.
• Test inlet valve coil: With power disconnected, locate the electronic inlet valve on the valve head. Check the coil resistance with a multimeter; an open circuit indicates a defective coil that must be replaced.
• Restore operation: Reopen the inlet valve slowly, check for leaks, reconnect power, and start a manual regeneration to confirm the error is cleared.