If a smoke alarm has sounded, or if it features a red light that blinks several times a minute, you will need to reset the alarm to restore it to the way it is supposed to function. There are a couple of ways that you can reset smoke alarms.
Slide or pop open the section of the smoke alarm that holds the batteries.
Remove the old battery or batteries.
Insert a new battery or batteries and close the cover. You now have reset the smoke alarm.
Stand on a stool or ladder tall enough to reach the smoke alarm.
Press the "Test" button on the alarm.
Hold the "Test" button until the lights have stopped flashing or the noise quiets. You have now reset the smoke alarm.