Built-in Miele coffee systems track mineral buildup closely, so a descaling prompt that keeps returning right after you’ve run the program is a signal worth taking seriously rather than dismissing.
Confirm the Program Actually Completed
The most common cause is an interrupted descaling cycle — often from opening the water tank door partway through, or the program being cancelled accidentally. Check your manual for the full program length and make sure it ran uninterrupted, start to finish.
Use the Right Descaling Solution
Generic descaling tablets not rated for your specific system can under-treat heavy scale buildup, leaving the sensor reading residual mineral deposits even after a completed cycle.
When It’s a Sensor, Not Scale
If you’ve run a full, uninterrupted cycle with the correct solution and the prompt still won’t clear, the conductivity sensor that measures water hardness may itself be reading incorrectly.
Next Steps
Persistent false descaling prompts are one of the more common built-in coffee machine faults we diagnose. Visit our coffee machine repair page to book a visit.