If you prefer to start and stop the Z2 using the Start / Stop Button, you can disable the Auto Start / Stop Feature. 

To do this press and hold the Up Arrow Button and Down Arrow Button at the same time until the Z-Breathe setting

flashes. Release the buttons.   

Then press and hold the Up Arrow Button and Down Arrow Button at the same time again until Auto on flashes. 

Release both buttons and press the Down Arrow Button once to change to off.  

Press and hold the Start / Stop Button to save the setting, you will the word ACCEPT. 

To enable the feature, repeat the steps above, but press the Up Arrow Button once to change to Auto Start/Stop and hold until you see the word ACCEPT.

Please Note:

The Auto Start / Stop feature will stop the therapy if a large air leak is detected between the Z2 outlet and the mask. This may also happen at times when the mask is not being worn properly. This common condition should be resolved once all connections are secure, the mask is properly worn, and the Start/ Stop Button has been pushed or you start breathing into the mask.

Please Note: 

The Auto Start / Stop feature may not work with the use of a full face mask due to its design. In this case you will need to disengage the feature and press the Start/Stop Button to start and stop the therapy.