E16 displayed, high conductivity or hardness detected after softener

Safety: Turn off power before disconnecting any sensor wiring.

• 1. Verify with independent test: Use a hardness test kit or TDS meter on softened water to confirm whether water is actually hard or if the sensor is misreading.
• 2. Inspect sensor: Locate the RainSoft outlet quality sensor (often in a tee fitting). Remove and inspect the probe tip for scale or iron deposits. Clean gently with vinegar and a soft cloth.
• 3. Check wiring: Ensure the sensor cable is intact and firmly connected to the control board.
• 4. Recalibrate (if supported): Some models allow sensor calibration in installer mode. Follow the manual to recalibrate using known-good water.

Next step: If E16 persists and independent tests show soft water, replace the outlet water quality sensor.