Humidifier turns off shortly after starting, indicator shows tank is empty even when full

Safety: Unplug the humidifier and remove the tank.

• Inspect float mechanism: Look inside the base for a floating ring or arm. Ensure it moves freely up and down. Clean any mineral deposits with warm water and vinegar.
• Check tank valve: Verify the tank cap and valve seal are intact and not stuck closed. When inverted, pressing the valve should release water.
• Magnet and sensor: Many Stadler Form units use a magnet in the float and a reed or Hall sensor on the PCB. Confirm the magnet is still attached to the float. If the sensor is loose or corroded, it may need replacement.
• Reassemble and test: After cleaning and verifying movement, refill the tank, seat it properly, and test. If the problem persists, replace the water level sensor assembly.