How to reset the alarm host?

Please switch off the power before resetting. Keeping pressing the "SET" button, as well as switch on the power button. Don't release the "SET" button until you hear 3 "beep.." sounds from the alarm panel. (Resetting is successful after hearing 3 beep sounds)After it, please wait for 25 seconds, the alarm host with2 beep sounds and it gets into normal working status, you can operate the alarm system again.