Display shows E05 and vacuum motors will not start, or they start briefly then shut down.

Safety: Unplug the machine before inspecting hoses or internal wiring.

• Check for airflow restriction: Disconnect the vacuum hose from the machine and wand. Inspect for clogs, debris, or collapsed hose sections. Clear any obstructions and ensure the hose is not kinked.
• Inspect waste tank filter: Remove the waste tank lid and locate the vacuum intake filter or screen. Clean thoroughly with water and mild detergent. Allow to dry completely before reassembly.
• Test vacuum motors individually: If accessible, disconnect one vacuum motor at a time and run the machine (if design allows). If E05 only occurs when a specific motor is connected, that motor is likely shorted or drawing excessive current. Replace the faulty Prochem vacuum motor.
• Check motor wiring and brushes: Inspect motor leads for burn marks or loose terminals. If the motor has serviceable brushes, check for excessive wear and replace brush sets if near end of life.
• Control PCB / relay: If motors test good and airflow is clear, the vacuum motor relay or current-sensing circuit on the control PCB may be faulty. Replace the control PCB.