This condition indicates a loss of utility power. If the power is out, the system will continue to run on the backup battery in power save mode to maximize battery life. If the power is on, ensure the transformer powering the security system is plugged in and that the outlet is working. Press the ‘*’ key to acknowledge the trouble. This will silence it for 2-3 hours. If the condition persists, pressing ‘*’ after 10pm will silence the condition until 8am the next morning.