Symptoms
• Machine displays E10 error code on the digital display and stops operation
• Brewing cycle fails to start or stops mid-cycle
• No water flows from the brew group during attempted brewing
• Machine beeps repeatedly and requires manual intervention to clear the error
• Previously brewed coffee was weaker than normal or incomplete
• Water tank appears full but machine does not recognize water is present
Possible Causes
• Water tank is not properly seated in the machine or has become dislodged
• Water tank is empty or water level is below the minimum fill line
• Mineral scale buildup from hard water (common in many USA regions) has blocked internal water lines or sensors
• Water inlet valve is stuck, clogged, or malfunctioning due to mineral deposits
• Water level sensor has failed or lost connection due to mineral accumulation
• 120V power supply fluctuation or loose electrical connection affecting sensor operation
• Brew unit is not correctly inserted or locked into position
• Frozen or blocked water line if machine is stored in cold environment
Safety Checks You Can Do
• Check that your home circuit breaker for the outlet is in the ON position; reset if tripped
• Unplug the machine for 60 seconds, then plug it back in to perform a hard reset
• Remove the water tank completely and inspect the tank seat area for debris or mineral residue, then clean with a soft cloth
• Refill the water tank with fresh, cold filtered water above the minimum fill line and firmly reseat it into the machine
• Run a full descaling cycle using approved descaling solution appropriate for 120V Bosch machines to remove mineral buildup from internal water lines and sensors
• Power on the machine and allow it to complete the descaling cycle fully before attempting regular brewing
• Check that the brew unit (if removable) is clean, properly aligned, and fully locked into the locked position
• Inspect the bean hopper to ensure it is not empty; add fresh beans if needed
• Empty and clean the drip tray and grounds container to ensure no overflow is blocking sensors
• Wait 5 minutes after descaling completion and attempt a test brew with just water to verify E10 error has cleared
• If error persists after these steps, the water inlet valve or sensor may require professional service
Safety First
Always disconnect the appliance from power before performing any checks. If you are unsure about any step, please contact a qualified technician.