If the customer is raising a ticket stating the device is making noise:
Kindly cross-check with the customer did his main water tank is filled or empty if it is empty and also if the inlet pipe is half on or off then the device will start making a noise.
Types of noise
1- Click Noise
2- Hammering Noise
3- Vibration Noise
In this situation please off the device for 10 seconds and switch it on if the sound stopped no issue sound only because of Power Variation.
If it continues we need to send technician Suspect for these cases SV and Pump.
Note: If after checking the above details the noise still continues then move the ticket to the operations team to assign a technician for the customer.