• 1. If the operation button is not working,
• - Self-check list
• Check whether the charging is completed or not.
• Check whether there is water in the tumbler.

• - Cases to visit service center
• Problem with electrode.
• Lamp malfunction.
• Mal-connection with USB cable circuits etc.
• Causes unknown or undetected.

• 2. If hydrogen rate significantly lower than before
• - Dissolve 3g of citric acid into 350㎖ of water, then run the self-cleaning operation for 5 minutes.