Waterway digital pool pump attempts to start, hums briefly, then stops and shows E03.

Safety first: Turn off the breaker and ensure the pump cannot start automatically.

• Check for hydraulic blockage: Remove the pump lid on the Waterway pump housing. Clean out the pump basket and check for debris lodged at the suction port.
• Inspect impeller: With the lid off and power off, reach through the diffuser opening (or remove the diffuser on some models) and try to spin the impeller by hand. It should turn smoothly. If it is jammed, remove debris carefully. Do not use excessive force that could crack the impeller.
• Check motor shaft rotation: Remove the rear motor cover and rotate the shaft with a screwdriver in the slot or with pliers on the flat of the shaft. If the shaft is stiff or frozen, the motor bearings may be seized.
• Restart: Reassemble, prime the pump, restore power, and press START. If E03 persists with a freely spinning impeller, the motor windings may be shorted and the motor assembly should be replaced.