Coffee maker makes loud gurgling, rattling, or knocking noises during brewing.

Safety first: Keep hands away from hot surfaces while the unit is operating.

Eliminate air and low water:

• Fill the reservoir to the MAX line and ensure it is fully seated.
• Run a water-only brew cycle to purge air.

Descale:

• Perform a full descale cycle to reduce noisy boiling caused by scale.

Some gurgling is normal, but if noises are very loud or grinding-like and persist, the pump may be failing and should be checked.