E15 error and the unit reports low salt even when the tank is full (on models with salt sensor)

Safety first: Unplug the softener before adjusting the sensor or wiring.

• Verify salt type: Nobel softeners are typically designed for clean, evaporated salt pellets or tablets. Using rock salt or very fine salt can affect sensor readings and cause bridging. Replace with the recommended salt type.
• Check sensor height: Ensure the salt sensor is mounted at the correct level as specified in the installation manual. If it is too high, it may always read low.
• Recalibrate (if supported): Some models allow salt sensor calibration in the installer menu. With the tank at a known level, follow the on‑screen prompts to recalibrate.
• Clear error: After adjustments, clear E15 via the control panel and monitor the displayed salt level over several days.

If the sensor continues to misread despite correct installation and salt type, replace the salt level sensor with a compatible Nobel part.