Brew water has a metallic or off taste, even with fresh beans and clean grinder.

Safety first: Allow the machine to cool before performing extended flushing.

• Flush thoroughly: Run multiple full reservoirs of fresh water through the brew group and hot water tap to remove any residual chemicals.
• Backflush with detergent: Clean the group head and three-way valve using espresso machine detergent to remove rancid coffee oils.
• Check water quality: Use filtered, non-softened water with low mineral content. Avoid heavily chlorinated or softened water.
• Break-in period: New machines or newly replaced copper/brass parts may impart a slight taste initially. This usually diminishes after several tanks of water and regular use.