You can manage 36 Nest Protects in total, with the maximum of 18 per home.

If you want to silence a Heads-Up alert for smoke or carbon monoxide, press the Nest button. However, if the smoke has reached emergency levels, Nest Protect can't be silenced, as required by regulation in the US and Canada. Address the source of the problem and Nest Protect will quiet down when the smoke level gets lower.

To find out what's wrong, you can either push the large Nest button or check your app for status details.

To reset your Nest Protect press and hold the Nest button. While holding the button Nest will chime and glow blue. Continue holding the button until Nest Protect speaks its version number, then release the button. Nest Protect will start a verbal countdown and tell you it’s erasing all settings, after a few seconds it will restart. (You can cancel this process by pressing the Nest Button at any time during the countdown.)"