Most new units have an auto off feature. If your machine is shutting off throughout the night and this feature is turned on it is most likely due to an elevated mask leak. Try adjusting your mask or trialing a different style to correct the mask leak. When the mask leak is too high the machine has a hard time determining if you have taken the mask off or not and the auto off feature will turn the machine off. If this is not the case please contact our office so we can help ensure your machine is functioning correctly.