Water remains hard at taps even though the BWT Perla appears to operate normally

Safety first: No electrical work is required for basic checks, but close isolation valves if opening plumbing connections.

• Test water hardness: Use a BWT hardness test kit to measure hardness at the inlet and outlet. If both are similar, softening is not occurring.
• Check bypass position: Ensure the BWT Perla bypass valve is fully closed and the unit is in service position. A partially open bypass will mix hard and soft water.
• Verify settings: In the menu, confirm that the raw water hardness and capacity settings match your local water analysis. Increase regeneration frequency if consumption has increased.
• Run manual regeneration: Perform a full manual regeneration and retest hardness after completion.
• Resin condition: If hardness remains high, the resin bed may be exhausted or fouled (e.g., by iron). Plan for resin replacement or professional cleaning of the resin vessel.