E08
Grünbeck Raw Water Hardness Sensor Fault (if equipped)

Display shows E08 and the unit reports a sensor error for raw water hardness

Advertisements

Safety Warning

This repair may involve working with high voltage components or water connections. Always unplug the appliance before removing any panels.

If you are not confident in your ability to perform this repair safely, we strongly recommend contacting a professional technician.

Advertisements

Possible Causes

Hardness sensor probe fouled, Sensor cable damaged, Sensor electronics defective, Incorrect sensor calibration

How to Fix / Troubleshooting

Safety: Disconnect power and close water supply if removing any wetted parts.

  • Check connections: Locate the raw water hardness sensor (often installed in a bypass line or mixing valve). Ensure the plug is fully seated and the cable is intact.
  • Clean probe: Remove the sensor according to the manual. Gently clean the probe surface with a soft cloth and mild detergent to remove scale or biofilm. Rinse thoroughly.
  • Reinstall and calibrate: Refit the sensor with new sealing rings if necessary. In the control menu, perform a sensor calibration using a known hardness value or test kit as specified by Grünbeck.
  • Replace if needed: If the error persists or readings are unstable, replace the hardness sensor module with an original Grünbeck part.
Advertisements

Repair Difficulty

Medium 3/5

Required Part

Raw Water Hardness Sensor
Check Price on Amazon

We may earn a commission from links on this page.

Advertisements