Display shows E01 and the unit does not start regeneration

Safety first: Disconnect the BWT Perla from mains power before opening any covers. Close the inlet and outlet isolation valves to relieve pressure. Have towels ready for minor water spills.

• Check household water supply: Verify that there is water at other taps. If the building supply is off, restore water and then reset the softener by disconnecting power for 30 seconds and reconnecting.
• Verify inlet shut‑off valves: Ensure the inlet and outlet ball valves to the BWT Perla are fully open. Many installations have a bypass valve; confirm the bypass is closed and the softener is in service position.
• Clean inlet filter screen: At the BWT Perla inlet connection, remove the union nut (have a bucket ready). Carefully pull out and rinse the small mesh filter screen under running water to remove debris, then reinstall.
• Check inlet solenoid valve operation: Restore power, initiate a manual regeneration from the control panel, and listen for a click at the valve head. If there is no sound and no water flow, the inlet solenoid on the valve block may be defective and should be replaced as a complete valve head assembly.
• After checks: Slowly reopen valves, check for leaks, and run a manual regeneration to confirm the error clears.