Pump stops shortly after starting, controller shows E02 and will not restart until power is cycled.

Safety: Turn off and lock out the electrical isolator before inspection.

• Check ventilation: Inspect the Certikin motor body and cooling fins for dust, cobwebs, or debris. Clean with a soft brush and vacuum. Ensure the plant room has adequate ventilation and is not excessively hot.
• Inspect cooling fan: On many Certikin motors, a plastic fan is fitted at the non-pump end. Remove the fan cover and confirm the fan is intact and spins freely with the shaft. Replace if broken or missing.
• Check bearings: Rotate the shaft by hand. Roughness, grinding, or stiffness indicates worn bearings, which cause overheating. The motor will need bearing replacement or a full motor swap.
• Verify load: Ensure valves on suction and return lines are correctly set. Running with severely restricted flow can increase motor load and temperature.

If the motor continues to trip on E02 after cleaning and improving ventilation, arrange for a motor insulation and load test by a qualified technician and consider replacing the motor.