DIAGNOSIS The centrifugal valve is not sealing or spinning at the correct speed. This is often due to scale buildup or a worn silicone seal.
FIX Run a thorough descaling cycle first. If problem persists, inspect the silicone seal inside the brewing head. Lift the lever fully. The gray silicone seal is at the top center. Check for tears, coffee grounds, or deformation. Clean it with a damp cloth. Run several blank cycles (press button three times for cleaning cycle) to clear any residual grounds affecting spin.
IF THAT DIDN'T WORK The machine may not be reading the capsule barcode correctly, defaulting to a low-volume brew. Try capsules from a different batch. If all capsules from any batch brew weak, the optical barcode reader is likely faulty.
HEADS UP Water temperature is also critical for extraction. If output is below 160°F, the thermoblock is failing. Weak, lukewarm coffee confirms a heating issue.