Visible mold or mildew inside the water reservoir or internal passages (musty smell).

Safety first: Do not drink coffee from a machine with visible mold until it has been thoroughly cleaned.

• Clean reservoir: Remove the reservoir and wash with warm soapy water. Use a soft brush to scrub corners and seams. Rinse thoroughly.
• Sanitize: Fill the reservoir with a solution of 1 part white vinegar to 3 parts water and let sit for 30 minutes, then run a brew cycle. Discard the solution.
• Flush system: Run 2–3 full reservoirs of fresh water to remove any remaining vinegar and loosened residue.
• Dry between uses: When not in use, empty the reservoir and leave the lid open to allow drying.
• If odor persists: Internal areas may be contaminated; repeated cleaning cycles may help, but severe contamination may warrant replacement of the unit.