Deborah, try this first:"
Press and hold for 3 seconds the "Control Lock/Unlock" button on the control panel to lock the control panel. Listen for a double beep and observe the "Control Lock" status light is lit when the control lock is in effect. Press and hold for 3 seconds the "Control Lock/Unlock" button on the control panel to unlock the control panel. The "Control Lock" status light is goes out when the control panel is unlocked.