Machine stops and displays E3 after a short period of use; body feels unusually warm.

Safety first: Switch off and unplug the machine. Allow it to cool for at least 30 minutes before opening any covers.

• Check airflow paths: Inspect all air intake and exhaust grilles on the machine body. Remove dust, lint, and carpet fibres with a soft brush or vacuum.
• Clean filters: If your Numatic carpet cleaner has motor protection filters or exhaust filters, remove and clean or replace them according to the user manual.
• Inspect cooling fan: Some models use a dedicated cooling fan for electronics or motor. Access the fan area and ensure the fan spins freely and is not obstructed by debris.
• Check thermal cut-out: Locate the thermal cut-out or temperature sensor on the motor or PCB. Ensure its wiring is intact and connectors are firmly seated.
• Usage conditions: Avoid running the machine continuously for longer than recommended duty cycles. Allow rest periods in heavy use.
• Test again: After cleaning and cooling, plug in and test. If E3 recurs quickly, the thermal sensor or main PCB may be faulty and should be checked by a service technician.