Keurig K-Supreme Plus: Known Problems

Coffee grounds can collect in the brewer's exit and entrance needles. Keurig says that causes grounds in your cup, and a clogged exit needle can cause a partial cup. You clear them with a straightened paper clip.

Keurig says mineral scale can build up in the brewer and hurt its performance if you leave it. It tells you to descale every 3 months, or when the descale notification comes on. If the brewer is heavily scaled, you may get little or no water out after adding descaler.