Display shows E18; machine may not recognize the AquaClean or water filter, or may request frequent filter changes.

Safety first: Disconnect power before handling the water tank and filter.

Step-by-step checks:

• Prepare filter correctly: Soak the AquaClean filter in water for the time specified in the manual, then shake to remove air bubbles before inserting into the tank.
• Install firmly: Push the filter straight into the tank connector until it is fully seated.
• Reset filter setting: In the machine menu, confirm or reset the filter installation according to the user manual.
• Test without filter: Remove the filter and test the machine. If E18 disappears, the filter is likely clogged or defective.

When to call a technician: If E18 persists even without a filter, the flow meter or control logic may be faulty and should be checked by a service center.