Check that you are the last person to leave the house or the last person to go to bed. Make sure all the doors and windows are closed; house alarms that sound when someone opens a door or window may not work if there are open doors and windows at the time the alarm is set.
Locate the alarm system remote panel near the main door to your home. The remote panel features a numerical keypad.
Tap the digits that make up your alarm code number on the remote panel's keypad. The alarm system beeps as you press each number, so you know that the system recognized your entries.
Press the Entry or Set button on your remote wall panel. This activates your alarm system.
Leave the house or go to bed immediately. You typically have 30 seconds to three minutes to leave the house before the alarm system is fully activated. If you open doors or windows after this period, the alarm may sound. If your house alarm is activated by motion in certain rooms, notify other members of your household that the alarm is set, so they know not to visit rooms of your home armed with motion sensors.