Digital Onga pump controller shows E03 and pump will not run, often after a storm or power surge.

Safety: Isolate power and discharge capacitors before handling. Capacitors can hold charge.

• Locate the capacitor: On most Onga pool pumps, the capacitor is in a cylindrical or oval housing on top or side of the motor. Remove the cover screws carefully.
• Visual inspection: Look for bulging ends, cracks, or oil leakage. Any of these signs indicate replacement is required.
• Check connections: Ensure spade terminals are tight and not corroded or burnt. Clean light corrosion and re-crimp loose terminals.
• Replace capacitor: If suspect, replace with an identical microfarad (µF) rating and equal or higher voltage rating, suitable for Onga motors. Mount securely and refit the cover.
• Inspect terminal block: Open the motor terminal box and check for burnt or loose connections. Tighten screws and replace any charred components.

If E03 remains after capacitor replacement and wiring checks, the motor start winding or electronic controller may be damaged and should be tested by a technician.