Check to make sure the Kevo app is running.
If you have verified that your Bluetooth function is turned on and your lock is still unresponsive, your Bluetooth Sharing may have been turned off.
To turn Bluetooth sharing on for iPhone/iPad/iPod Touch:
1. Navigate to Bluetooth Sharing inside your Settings menu (Settings > Privacy > Bluetooth Sharing).
2. Verify that sharing is turned on for the Kevo app. If it is not already on, simply tap the on-off switch to turn it on.