Why does my sous vide stick make a rattling or buzzing sound?

A low sound from the circulating water can be normal, but rattling or buzzing should be checked promptly. If the noise is sharp, new or accompanied by vibration, heat or poor performance, stop using the appliance until you know it is safe.

1. Check that the stick is fitted securely to the container and not touching the sides or base. The expected result is a stable fit with no loose movement. If it is knocking against the bath, reposition it.
2. Look for trapped air, bags or utensils near the water intake or circulation area. The expected result is unobstructed water flow. If something is blocking movement, clear it away.
3. Confirm that the water level is correct and the bath is not too shallow. The expected result is smooth circulation without splashing or strain. Low water can make pumps and heaters sound louder than normal.
4. Listen for a change when the unit is moved slightly within its safe mounting position. If the sound changes when it is no longer touching the container wall, the noise is likely caused by contact rather than an internal fault.
5. If the noise continues even with correct setup, unplug the appliance and stop using it. Contact the retailer or store where it was purchased.

Do not keep cooking if the sound becomes harsher, the appliance vibrates strongly or the noise appears together with burning smell or loss of heat. That is the point to stop using it.