Display shows E10 and the unit reports an internal temperature or overload condition; regeneration may be aborted.

Safety first: Unplug the softener immediately if you smell burning or see smoke. Do not continue to operate a unit with signs of overheating.

• Check transformer rating: Verify the wall transformer matches the Tier1 specification (correct voltage and VA rating). Using an incorrect transformer can overheat the board.
• Inspect wiring: Remove the control head cover and inspect all low-voltage wiring for melted insulation, shorts to metal, or pinched cables. Repair or replace damaged harnesses.
• Test motor circuit: Disconnect the valve motor from the board and measure its resistance. A very low resistance (near 0 ohms) indicates a shorted motor that can overload the board.
• Run without motor (brief test): With the motor unplugged, power the unit and see if E10 appears. If the error disappears, the motor or its wiring is the likely cause. Replace the valve motor or harness.
• Replace control board: If E10 persists with all loads disconnected, the control board has an internal fault and must be replaced.