What does a blinking blue light on a smoke detector mean? BLUE/CO: Blue light flashes rapidly when sensor detects elevated CO levels. Horn alarms 4 times, pauses, repeats. RED-YELLOW-ORANGE/SMOKE: Patented Red-Yellow-Orange light flashes rapidly when sensor detects elevated smoke levels.
What color should my smoke detector be blinking? Red LED Indicator: The red LED will blink in conjunction with the alarm sound. Therefore, the red LED will blink during a smoke alarm, a low battery mode chirp, a unit error mode chirp or at end of unit life.