E11 error appears and the unit will not recognize the clean water tank.

Safety first: Unplug the Philips carpet cleaner.

• Reseat the tank: Remove the clean water tank and reinstall it firmly until you hear or feel a click. Ensure it is not tilted or misaligned.
• Inspect tank base: Check the bottom of the tank for a small magnet or actuator tab that engages the sensor. If broken or missing, the tank may need replacement.
• Check latch and guides: Make sure the tank slides smoothly into its guides and the latch is not bent or cracked.
• Sensor inspection: Locate the tank presence sensor in the base (microswitch or reed sensor). Clean around it and verify that it is not physically damaged. Reseat its wiring connector on the PCB.
• Component replacement: If the sensor does not change state when the tank is inserted (test with a multimeter), replace the sensor or the entire sensor harness.