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

Author: Edna Williamson V  |  Last update: Friday, April 11, 2025

How to test your carbon monoxide detectors to ensure they are working properly? To test your carbon monoxide detectors, press and hold the test button on the alarm. The detector will sound 4 beeps, a pause, then 4 beeps for 5-6 seconds. Refer to the user manual for your specific model.

How to tell if a carbon monoxide detector is working?

If you're wondering how you can check that your carbon monoxide detector works, the answer is simple: testing. You should test your CO detector monthly to ensure your family's safety. The test button is the best way to test it because it will tell if the alarm is still sounding.

What color should the light be on a carbon monoxide detector?

Meaning: A flashing red light typically indicates that the detector has sensed carbon monoxide in the environment.

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.

Is there a way to test for carbon monoxide at home?

The easiest way for a consumer to check for CO in the home is to buy an NCI carbon monoxide detector. It will tell you accurately your CO levels as low as 5 ppm. It is portable as well as wall mounted. Or you can call a heating contractor to test your home.

How to test a CO detector

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.

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.

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.

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. Contact 911 or your local fire department to report the incident.

What do 4 beeps on a carbon monoxide detector mean?

4 Beeps and a Pause: EMERGENCY. This means that carbon monoxide has been detected in the area, you should move to fresh air and call 9-1-1. 1 Beep Every Minute: Low Battery. It is time to replace the batteries in your carbon monoxide detector. 5 Beeps Every Minute: End of Life.

Why is there no green light on my carbon monoxide detector?

If the red or green light on your CO detector is illuminated, that's a sign that the unit has power. If the light is off, replace the batteries and follow the reset steps.

How can you tell if there is carbon monoxide without a tester?

Black and yellow stains, yellow flames (instead of blue), and blown-out pilot lights in gas appliances can all be signs of a carbon monoxide leak. Condensation build-up on windows near gas appliances can also indicate a leak. If you have a fireplace, you might notice smoke build-up, too.

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.

How to detect carbon monoxide with iPhone?

Go to the Home app on your iPhone or iPad. , then tap Home Settings. Tap Safety & Security. Tap Sound Recognition, then turn on Smoke & CO Alarm.

How to test for carbon monoxide in your home?

A carbon monoxide test is performed using a portable, electric detector to determine the presence of carbon monoxide in your home and how much of the toxic gas it contains in parts per million (ppm).

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.

How can I check my carbon monoxide detector?

How to test your carbon monoxide detectors to ensure they are working properly? To test your carbon monoxide detectors, press and hold the test button on the alarm. The detector will sound 4 beeps, a pause, then 4 beeps for 5-6 seconds. Refer to the user manual for your specific model.

Can you air out carbon monoxide?

If you have carbon monoxide in your home, go outside to get fresh air immediately. Don't reenter your home until local emergency services tell you it's safe to do so.

Should I call 911 if my carbon monoxide alarm goes off?

My carbon monoxide alarm is sounding. What should I do? Call 911 and report what is happening. Immediately leave your residence and wait for the fire department to arrive.

How much does it cost to get your house checked for carbon monoxide?

Professional carbon monoxide testing can cost from $100 to $200+. But, most homeowners usually have carbon monoxide detectors which can range from $20 to $150+, according to Home Advisor, depending on the detector type.

How do firemen check for carbon monoxide?

Using Carbon Monoxide Meters to Detect and Monitor Carbon Monoxide Levels. The Sensorcon Inspector is a trusted tool used by firefighters and emergency medical technicians in detecting and identifying the source of carbon monoxide (CO) during fire and rescue activities.

Who do you call to check for carbon monoxide?

Immediately go outside to get fresh air, and right away call Poison Help (1-800-222-1222), which connects you to your local poison center. If you feel better when you are out of your home and worse when you return, CO may be present. If you notice this, call 911. Have the fire department check for CO in your house.

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