How do you know when your carbon monoxide detector is going bad?

Author: Sophia McClure  |  Last update: Thursday, October 9, 2025

30-Second Beeps from Carbon Monoxide Detector When the detector is making chirping sounds every 30 seconds, this is not the same as a continuous siren. The chirping sound usually indicates the alarm is near its end of life and requires replacing. Carbon monoxide detectors have a seven-year lifespan.

How do you know if your carbon monoxide detector needs to be replaced?

1 beep every minute: This means that the detector has low batteries and you should replace them. 5 beeps every minute: This means your alarm has reached the end of its life and needs to be replaced with a new carbon monoxide alarm.

How can I tell if my carbon monoxide detector is working?

Here's a simple guide:
  1. Smoke alarms alert you with three beeps in a row.
  2. Carbon monoxide alarms alert you with four beeps.
  3. A single chirp means the battery is low or the detector should be replaced.

Can carbon monoxide detectors give false readings?

While CO detectors are designed to be reliable, various factors can cause them to beep erroneously. False alarms can be caused by incorrect installation, placement near a source of fumes or steam, or even a buildup of dust and dirt on the sensor.

What if the carbon monoxide alarm goes off but no fire?

False or nuisance alarms are when your smoke detector or CO alarm goes off, but there is no presence of smoke or carbon monoxide in your home. However, if your smoke or carbon monoxide detector sounds indicating an emergency and you are not certain it is a nuisance alarm, evacuate the home and call 9-1-1.

What to Do When Your Carbon Monoxide Detector Goes Off

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.

Will opening a window help with carbon monoxide?

If you experience symptoms that you think could be from CO poisoning: DO GET FRESH AIR IMMEDIATELY. Open doors and windows, turn off combustion appliances and leave the house.

Can anything else set off a carbon monoxide detector?

Artificial components, such as lighted incense or air fresheners, can trick your detectors with low levels of CO emitted into the air.

What to do if a carbon monoxide alarm goes off and then stops?

If you have a carbon monoxide detector chirping and then it stops, it's important to take the situation seriously, even if the alarm is no longer sounding. Even if the alarm has stopped, get everyone out of the home to a place with fresh air.

What number should be on a carbon monoxide detector?

What is an acceptable level of carbon monoxide? For indoor settings, the acceptable level of carbon monoxide is stated by WHO which recommends 9-10ppm for no more than 8 hours. 25-35ppm for no more than 1 hour and 90-100 ppm for no more than 15 minutes.

Does the fire department charge to check for carbon monoxide?

In most areas, the fire department does not charge to respond to carbon monoxide alarms or to check for the presence of CO in a residence. However, policies can vary depending on the jurisdiction or specific fire department. It's always a good idea to contact your local fire department for specifics on their policies.

How to tell if carbon monoxide is in the air?

The best way to alert you and your family to unsafe levels of CO is to install a carbon monoxide detector. It works like a smoke alarm, sampling the air in your home and creating a loud alarm when levels of the gas are detected. It's important to evacuate your home immediately when your CO alarm sounds.

Does 3 beeps mean carbon monoxide?

When the carbon monoxide alarm senses a dangerous level of CO gas, the unit will emit a loud alarm pattern. The alarm pattern is four short beeps – followed by five seconds of silence – followed by four short beeps. * This could mean that: Your alarm may have detected carbon monoxide.

How can I check if my carbon monoxide detector is working?

To test a carbon monoxide detector, locate the “test” button on your device. Press and hold this button until you hear two beeps or chirps. If you have interconnected alarms operating on the same security system, they should beep together. Your detector may flash a light instead of or in addition to the beeps.

Is my carbon monoxide detector malfunctioning?

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.

What is the life expectancy of a carbon monoxide detector?

Carbon Monoxide Detector Replacement FAQs

To determine if your carbon monoxide non-digital alarm has reached its end of life, refer to the following: When the CO alarm emits a quick beep every 30 seconds and the red LED flashes, the unit has reached the end of its 7 or 10 year life.

What if carbon monoxide alarm goes off but no fire?

Your carbon monoxide alarm is going off for one of the following reasons: It is doing its job properly and detects CO pollution in the air. It is a false alarm caused by other household items. The detector is malfunctioning or the batteries need changing.

What else can trigger a carbon monoxide detector?

Any fuel-burning appliance that is malfunctioning or improperly installed. Furnaces, gas ranges or stoves, gas clothes dryers, water heaters, portable fuel-burning space heaters, fireplaces, generators, and wood burning stoves. Vehicles, generators, and other combustion engines running in an attached garage.

What does 4 beeps mean on carbon monoxide?

What Does an Emergency Alarm Chirp Mean? This meaning is probably the most self-explanatory. When your carbon monoxide detector chirps 4 times in a row and pauses, this means it has detected unsafe levels of carbon monoxide. This means your entire household should evacuate immediately and seek fresh air.

Can a carbon monoxide alarm go off for no reason?

The carbon monoxide alarm going off could mean the gas is present in your home or office, or simply indicating the battery or alarm needs replacing. The deadly gas is a product of partial combustion of carbon-based compounds where there is not enough oxygen to create carbon dioxide (CO2).

What sets off carbon monoxide in house?

Carbon Monoxide sources in the home

CO is produced whenever a material burns. Homes with fuel-burning appliances or attached garages are more likely to have CO problems Common sources of CO in our homes include fuel-burning appliances and devices such as: Clothes dryers. Water heaters.

What can give a false carbon monoxide reading?

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.

How do you tell if you have a carbon monoxide leak?

Signs of a carbon monoxide leak in your house or home

Sooty or brownish-yellow stains around the leaking appliance. Stale, stuffy, or smelly air, like the smell of something burning or overheating. Soot, smoke, fumes, or back-draft in the house from a chimney, fireplace, or other fuel burning equipment.

Can dogs smell carbon monoxide?

Carbon monoxide, commonly known as CO, is an odorless, colorless, and non-irritating gas. No pet can identify the gas because CO lacks any scent whatsoever. Exposure can lead to carbon monoxide poisoning in both humans and pets.

Previous article
Is it safe to put Fabuloso in your toilet?
Next article
What is painting on plaster called?