Why does my Kidde smoke and carbon monoxide alarm keep chirping?

Author: Lizzie Herzog  |  Last update: Tuesday, January 6, 2026

Consistent Chirping If your carbon monoxide alarm is chirping or beeping once every 60 seconds, it may signify: Low Battery – The carbon monoxide batteries need to be replaced. End of Life Warning – Seven years after initial power up, a Kidde CO alarm will begin chirping every 30 seconds.

How do I stop my Kidde smoke and carbon monoxide alarm from beeping?

Press and hold the test button for at least 15 seconds. The unit may chirp or alarm for a few seconds before going silent. Reconnect the power and reinstall the battery. The unit will chirp once when the power is restored and should not chirp afterwards.

Why does my smoke detector keep chirping even after I change the battery?

When a smoke detector keeps beeping even after replacing its battery, it can mean that there is something preventing it from detecting the battery. It can also mean that there are too many system errors overwhelming its processor. You can try resetting the smoke alarm to manually clear the error from the processor.

Why does my carbon monoxide detector keep beeping even after I change the battery?

The chirping sound usually indicates the alarm is near its end of life and requires replacing. Carbon monoxide detectors have a seven-year lifespan. Replacing the battery does not stop this type of beeping. Detectors that plug into a wall socket may have a loose battery when these types of beeps occur.

Why is my kidde hardwired smoke detector chirping?

This battery characteristic can cause a smoke alarm to enter the low battery chirp mode when air temperatures drop. Most homes are the coolest between 2 a.m. and 6 a.m. That's why the alarm may sound a low-battery chirp in the middle of the night, and then stop when the home warms up a few degrees.

Why Does My Kidde smoke detector keep beeping even after I change the battery?

Why wont my hardwired smoke detector stop chirping?

The same thing may happen to hardwired alarms when you turn on the device's power. If the chirping continues, however, your detector might have a residual charge from the previous battery. Take out the battery, hold down the test button for 15 seconds, and replace the battery.

Where is the reset button on a Kidde hardwired smoke detector?

This is usually located on the front or side of the unit. Press and hold the reset button for at least 5-10 seconds. You may need to use a small tool, such as a paperclip or a pen, to press the button. You should hear a beep or see the lights on the alarm flash to indicate that the unit has been reset.

Why does my kidde smoke and carbon monoxide alarm keep going off with a new battery?

Dust and debris can affect the alarm. As far as it is concerned, the spider web or speck of dust that is obscuring the sensor is a potential fire and therefore the alarm needs to be sounded. The easiest way to clean an alarm is to run a vacuum cleaner over the vent.

Why is the green light blinking on my Kidde smoke and carbon monoxide alarm?

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.

What are two warning signs of carbon monoxide poisoning?

The most common symptoms of CO poisoning are headache, dizziness, weakness, upset stomach, vomiting, chest pain, and confusion. CO symptoms are often described as “flu-like.” If you breathe in a lot of CO, it can make you pass out or kill you.

How do I stop my smoke alarm from chirping without a new battery?

Take the individual chirping unit down: After shutting off the circuit breaker, take the individual unit down, remove the battery backup (if it has one), then hold the test button down for 15 seconds. This should reset your alarm and stop the chirping.

How to reset kidde carbon monoxide alarm?

While pressing the Peak Level Memory button, press the Test/Reset button for two seconds and release both at the same time. The number on the display will turn to 0, the memory will be cleared and the carbon monoxide (CO) alarm will begin monitoring for CO.

Why does my kidde smoke detector keep saying low battery?

The battery may need to be replaced. An alarm will chirp every 30 to 60 seconds for a minimum of seven days. With a "low battery" announcement, disconnect the unit and replace the batteries. You can also put a unit into low battery hush for up to 12 hours on newer units by pressing the test/hush button.

Why does my Kidde smoke and carbon monoxide alarm keep beeping after power outage?

If your carbon monoxide detector is beeping after a power outage, it could be because a false alarm has been triggered, or it could be a signal of CO detection.

What can falsely set off a carbon monoxide detector?

Common causes of false alarms of carbon monoxide:
  • Close to cooking sources (10 feet minimum)
  • Close to sources of humidity (10-20 feet)
  • Near fireplaces.
  • Near water heaters.
  • Near furnaces.
  • Located in a poorly ventilated location like a garage, kitchen, or closet.

Why does my new Kidde smoke and carbon monoxide alarm keep beeping?

Consistent Chirping

If your carbon monoxide alarm is chirping or beeping once every 60 seconds, it may signify: Low Battery – The carbon monoxide batteries need to be replaced. End of Life Warning – Seven years after initial power up, a Kidde CO alarm will begin chirping every 30 seconds.

What is the difference between blinking and solid green light on smoke detector?

For some units, a green light flashing every 5 seconds signifies that the device is in “battery only” mode, powered by AC. When the detector senses a smoke or carbon monoxide hazard, the green light might become steady, whereas in “hush” mode, it may flash every 2 seconds.

How do you silence a Kidde smoke and carbon monoxide alarm?

Take the smoke detector off its mounting bracket on the ceiling and disconnect the power cable. Take out its battery, then press the “Test” button holding it down for 15 seconds. An alarm will sound for a short time, then the alarm will silence.

Why is the green light always on my Kidde smoke and carbon monoxide alarm?

Hardwired units will have a steady green LED light to show that it's receiving AC power. Battery-operated units will have a quick flash every 30-45 seconds. This does not necessarily mean the alarm is working. Pressing the Test button is the only recommended method.

How often should you replace Kidde smoke and carbon monoxide alarm?

Kidde recommends replacing your smoke alarms every5/ 10 years, and carbon monoxide alarms every 7/10 years. If you don't know how old your alarm is, look for the manufacturing date code on the back of the alarm(s) or simply replace them to avoid any danger​.

Why is my Kidde smoke alarm going off for no reason?

First, take the units down and clean them thoroughly using compressed air or a vacuum to remove any dust or debris that might be causing a false alarm. Next, do a reset by removing the batteries, holding down the test button for 15-20 seconds, then reinstalling the batteries.

Why is my Kidde smoke and carbon monoxide alarm blinking red light?

If the unit malfunctions, the red LED light will flash and the unit will chirp every 30 seconds indicating a system problem. If the red LED flashes every 60 seconds WITHOUT an audible chirp, this is the pre-warning that the battery will soon need replacing. The alarm is battery-operated with a 9V battery.

Why won't my Kidde smoke alarm stop beeping?

The alarm is low on battery. This is the most common cause of beeping alarms. The alarm will beep every 30 to 40 seconds to alert you that the battery needs to be replaced. To fix this problem, you need to replace the battery with a new one of the same type and size.

What does 3 beeps mean on a Kidde carbon monoxide detector?

If your detector makes three consecutive beeps around every five minutes, this indicates it is malfunctioning. Newer model detectors will prompt you by saying a recorded message or indicate through light colors. Look to replace your detector.

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