There could be a number of reasons for this. The following suggestions should help you to identify and resolve the problem: Check that your patient’s device is turned on and that the mask is properly adjusted. If you’re not sure how to adjust your patient’s mask, you might find our FAQs on Mask Fitting helpful. If your patient is experiencing high leak and Smart Start/Stop is turned on, it’s possible the device is stopping automatically because of the leak. Check that the power plug is fully and correctly inserted in the device. When it is correctly inserted, the power button will light up. Ensure that no blankets or other objects are covering the power supply unit or the device. Check whether the filter is clear. If it is blocked, replace the filter. For S9 therapy devices, check that the therapy device’s lid is properly closed. If your patient is using a humidifier, make sure the humidifier lid is also closed and that the humidifier tub is fully inserted. Make sure the patient is not using the Start/Stop button to light the LCD during the night, as this will stop the therapy. Check whether there’s a message on the screen. If there is, follow the instructions to clear the message. Try unplugging the device, then plugging it in again. From time to time there may be power disturbances that cause the device to power down. Ask your patient to check if other devices (e.g. alarm clock) have powered off at the same time. If your patient is set up on an activated AirSense 10 or AirCurve 10 therapy device, you will find useful information on AirView Remote Assist to help you troubleshoot the issue remotely.