Water at taps is slightly soft but not as soft as expected (residual hardness too high)

Safety first: Adjustments can usually be made without disconnecting power, but avoid opening pressurized components.

• Measure hardness: Test inlet and outlet hardness. Compare with the target residual hardness set for your BWT Perla model.
• Check blending valve: Many BWT Perla units have an adjustable blending or mixing valve. Refer to the manual and adjust the blending screw or knob to reduce the proportion of hard water mixed in.
• Verify controller settings: Ensure the target residual hardness or blending percentage is correctly set in the menu.
• Inspect for internal leakage: If adjustments have little effect, the valve head seals may be leaking internally, allowing hard water to bypass the resin. In this case, a valve head service kit or replacement is recommended.
• Resin channeling: If the resin bed has hardened or channeled, water may bypass most of the resin. A professional resin rebed may be required.