E12
U.S. Motors Communication Error Between User Interface and Drive

U.S. Motors variable-speed pool pump shows E12 and runs only at a fixed low speed or not at all.

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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.

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Possible Causes

Loose keypad/display ribbon cable, Damaged communication harness, Corroded low-voltage terminals, Failed user interface board

How to Fix / Troubleshooting

Safety first: Turn off power at the breaker before removing the keypad or display panel.

  • Check keypad connection: Remove the user interface panel and inspect the ribbon cable or harness connecting it to the main drive board. Reseat the connector firmly.
  • Inspect for corrosion: Look for green/white corrosion on low-voltage pins. Clean gently with contact cleaner and a soft brush.
  • Test with minimal configuration: Disconnect any external automation or RS-485 connections and test the pump with only the local keypad connected.
  • Replace interface: If E12 persists and the drive runs in a default mode only, replace the U.S. Motors user interface/keypad assembly. If a new keypad does not resolve it, the main drive board communication port is likely faulty.
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Repair Difficulty

Medium 3/5

Required Part

User Interface / Keypad Assembly
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