A flashing red and green light on a Kidde carbon monoxide alarm typically signals one of three issues: an active alarm/memory event, a sensor fault, or an end-of-life warning. The specific meaning depends on the flashing pattern and accompanying beeps:
An alternating flashing green and red light on a Kidde smoke detector usually indicates a sensor error, internal fault, or an end-of-life warning. It may also signal that the unit needs to be reset, or—if it is connected to a smart home system—a potential software update.
A carbon monoxide (CO) detector flashing alternating red and green usually indicates one of two things: a device malfunction/end-of-life or a low battery warning. It can also indicate the detector is going through an initial start-up cycle, depending on the specific model.
To reset your Kidde carbon monoxide (CO) alarm and clear persistent errors, press and release the Test/Reset button on the front of the unit.
Green Light: The green LED will be lit continuously or flash every 30 seconds to indicate the unit is operating properly. In Hush® mode the LED blinks every 2 seconds and once per second if it is the initiating alarm.
It is also a good idea to know the signs of a potential CO problem:
The green LED should flash once every 48 seconds, showing battery operation. Press the test button to ensure the alarm sounds loudly. Monitor the alarm for 3 minutes for any fault chirps or yellow LED flashes.
To tell if your carbon monoxide (CO) detector is bad, check for an expired manufacturing date, an unresponsive test button, or specific error beeps. Most detectors must be replaced every 5 to 10 years.
A pattern of 5 beeps every 30 seconds usually indicates that your carbon monoxide (CO) detector has reached its "End-of-Life". This means the internal sensor has expired and the unit can no longer safely detect CO gas.
To ensure your Kidde carbon monoxide (CO) alarm is working, follow these three simple steps to test and verify the unit.
A carbon monoxide detector usually flashes red to inform you that it is working on the detection of carbon monoxide. If it doesn't flash the red light, change the batteries immediately.
Carbon monoxide (CO) detectors can be triggered by high humidity, chemical fumes (like aerosol sprays or paint), hydrogen gas from nearby batteries, or simply dust, age, or low batteries.
A smoke detector blinking both red and green typically indicates one of three things: a low battery in a hardwired unit, a completed "hush/test" cycle after an alarm, or a device malfunction.
A midnight fire alarm is a jarring experience, but it’s usually caused by one of four common issues:
To silence a low battery chirp on your Kidde smoke and carbon monoxide alarm, remove the alarm from its mounting bracket or wall outlet, open the battery door, and swap out the old batteries. Always press the "Test" button after installing fresh batteries.
Sooty or yellow/brown stains on or around boilers, stoves, or fires. Smoke building up in rooms. Yellow flames coming out from gas appliances except at natural gas fireplaces. The pilot lights blow out frequently.
For hardwired units, a steady green LED light indicates that the alarm is receiving AC power. Battery-operated units will have a quick flash every 30-45 seconds.
A flashing red light on a Kidde carbon monoxide (CO) alarm indicates one of four things: it is detecting a dangerous level of CO, it has registered a previous alarm event, its batteries are dying, or the alarm has reached its end of life and needs to be replaced.
A carbon monoxide (CO) detector emits a continuous pattern of four loud, rapid beeps, followed by a pause.
To reset a Kidde carbon monoxide alarm and clear error codes, simply press and hold the Test/Reset button for 5 to 20 seconds, depending on the model. For a hard reset, remove the battery (or unplug the unit), hold the button to drain residual power, then restore power.
5 Beeps - Processor Failure
Troubleshoot CPU, motherboard.
Carbon monoxide (CO) false alarms are most frequently caused by expired sensors (usually 5–7 years), low or dead batteries, or dust and debris clogging the sensor chamber. Other common culprits include high humidity, cooking fumes, or the off-gassing of household chemicals and aerosols.
Because carbon monoxide (CO) is a colorless, tasteless, and odorless gas, it is impossible to detect with human senses. The only reliable way to know if it is in your air is by using a certified Carbon Monoxide Detector.
Carbon monoxide (CO) gas mixes evenly with air, so detectors are highly effective whether placed high on the ceiling or low on the wall. Experts generally recommend mounting them about 5 feet above the floor (eye level) or just a few inches below the ceiling.