On a WMF 1500 S+, “Empty grounds container” asks you to remove the used grounds. “Grounds container missing” asks you to seat the container correctly. The operating instructions require emptying, replacing and then confirming on the display. Taking the container out and putting it back full is not a completed emptying cycle.
Complete the physical task before confirming it
WMF describes raising the combi spout to access the container. Remove the container, empty it, put it back and confirm the action on the screen. Drink dispensing stays blocked while the container is out.
The warning about skipping the emptying step is explicit: the container can overfill, soil the machine and cause further damage. Confirming a task that was not done may clear the message, but it does not remove the grounds.
If the container will not go back into place, the manual says to check the chute for coffee residue. Don’t force the drawer or defeat its detection. Follow the machine’s cleaning instructions for accessible residue; leave a persistent seating problem for service.
The under-counter option changes where grounds collect
Some 1500 S+ installations use the optional disposal chute through the counter. Those machines pass the grounds through openings in the container and machine base into a separate receptacle below. That receptacle is easy to miss if the person emptying it assumes every machine has a closed drawer.
Identify which arrangement is fitted before assigning the closing task. WMF requires daily cleaning of the chute. The normal removable container also needs its daily cleaning, as specified in the care chapter. Emptying it during a busy shift does not replace that cleaning.
If the message remains
Note whether the screen requests emptying or says the container is missing. Tell us whether it appeared before removal, after replacement or after confirmation. If the container is empty and correctly seated but the message remains, ask for a WMF diagnosis. An operating message alone does not establish a sensor failure.
WMF service information covers pickup and bench diagnosis. Include the exact model and whether the machine has the under-counter chute when booking.
Source: WMF 1500 S+ User Manual, North America, Grounds Container, Cleaning Intervals, Manual Cleaning and Messages for Operation.