E11 error, unit loses time and settings after short power outages

Safety: Disconnect power before removing the control board.

• 1. Confirm symptom: Note the time and settings, then unplug the unit for 5–10 minutes. Plug back in and see if the time and program are retained.
• 2. Inspect backup components: On the PCB, locate any coin-cell battery or large backup capacitor. Check for leakage, swelling, or corrosion.
• 3. Replace backup battery (if present): If your RainSoft board uses a replaceable battery, install a new one of the same type and polarity.
• 4. Check outlet power: Verify the outlet is not controlled by a wall switch or timer that may be cutting power unexpectedly.

Resolution: If E11 persists and the board cannot retain memory, the control board must be replaced.