REMINDER is telling you that there is an excessive air leak. The most common reason for this to happen is that the mask is not being worn properly or is off completely. If the mask is on, check the following connections for air leaks: 

1. The tube adapter to the Z1™ and Z2

2. CPAP tube to the tube adapter

3. CPAP tube to mask

4. Mask to face (i.e. adjust the position of the mask and headgear to eliminate the leak.)