Troubleshooting My Philips Humidifier stopped working If your Philips Humidifier stopped working, there might be a simple solution. Discover in the following lines how to mend it yourself. The humidity level is 70% or more Your humidifier is designed to automatically switch off once the 70% RH (Relative Humidity) level is reached. The reason for this is that humidity above 70% is not comfortable for the users. If this is the case, then you should not worry, there is nothing wrong with your humidifier. The water tank is empty When the water tank is empty, your humidifier does not receive water and cannot function. To prevent this from happening, make sure there is water in the water tank. Note that the lower the humidity level in the room is, the faster the water tank will become empty. The top part is not placed properly When the top part of your Philips Humidifier (the upper unit) is not placed correctly over the water tank, these two pieces will not be fully connected and your purifier will not work. Please, double check that the top of your humidifier is placed correctly. There is a problem with the power supply Make sure the socket where your humidifier is plugged in functions correctly (try plugging a different appliance to that socket to check if it works).