Check that the dehumidifier is plugged in properly to the wall outlet if it stops running. Check the circuit breaker to see if it was tripped.
Remove the bucket and empty the bucket if it is full of water. Reinstall the bucket. The dehumidifier will not run if the bucket is not placed correctly or if it is full.
Close all windows and doors while running your dehumidifier. If they are left open, the dehumidifier will not shut off. It also may not shut off if the room is too large for that particular dehumidifier.
Clean the grill with the vacuum cleaner's brush attachment and move it away from any walls. Dehumidifiers need at least 12 inches of open space surrounding them in order to operate properly.
Wait one hour after turning the dehumidifier on for frost to disappear from the coil. The occurrence of frost is normal if you have just turned your dehumidifier on after it has been off for awhile. This is due to the refrigerant. If the frost does not go away, make sure the room temperature is above 41 degrees F.