Should you evacuate the building if you hear a carbon monoxide detector go off?

Author: Prof. Cassandre Lebsack PhD  |  Last update: Sunday, November 9, 2025

If the alarm is going off, make sure that everyone in the home immediately evacuates the building. Once safely outside, call the authorities so that they can evaluate your home and identify the cause of the leak.

Should I call the fire department if the carbon monoxide alarm goes off?

Yes, if a carbon monoxide (CO) alarm goes off, you should take it seriously. Here are the steps you should follow: Evacuate Immediately: Get everyone out of the building and into fresh air. Call 911: Once you are safe, call emergency services to report the alarm. They can send professionals to assess the situation.

Should I worry if my carbon monoxide alarm goes off?

Yes, if a carbon monoxide (CO) alarm goes off, you should take it seriously. Here are the steps you should follow: Evacuate Immediately: Get everyone out of the building and into fresh air. Call 911: Once you are safe, call emergency services to report the alarm. They can send professionals to assess the situation.

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 to do if the carbon monoxide alarm goes off in an apartment?

Call 911 immediately and report that the alarm has gone off. Do not assume it is safe to reenter the home when the alarm stops. When you open windows and doors, it helps diminish the amount of carbon monoxide in the air, but the source may still be producing the gas.

WHAT CAN TRIGGER A CARBON MONOXIDE ALARM? \\ What causes co detector to go off?

Should you open windows if carbon monoxide alarm goes off?

When you open windows and doors, it helps diminish the amount of carbon monoxide in the air, but the source may still be producing the gas. The levels can build up again once you go back inside and close the windows.

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.

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

Dial 911 right away to let emergency responders know your CO alarm has been activated. Don't re-enter the home, even after the alarm stops going off. Open doors and windows may allow the CO in your home to dissipate, but you don't know if the machine that triggered the alarm has stopped producing carbon monoxide.

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.

Can carbon monoxide detectors go off falsely?

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.

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 long should you wait after carbon monoxide alarm goes off?

If your CO alarm is going off, you should immediately grab your family and pets and get into fresh air. Open any windows you can on your way out. Once outside, call 911. According to the CDC, the most common symptoms include headache, weakness, nausea, chest pain, confusion or vomiting [2].

Can anything else trigger a carbon monoxide detector?

Even with the doors and windows open, any of these activities can trigger carbon monoxide detectors. Using a grill inside the garage or near open doors and windows–Not only is barbecuing among the most common CO-producing activities, but it can also be a fire hazard when done too close to your home.

Is carbon monoxide alarm an emergency?

If it still sounds, call the fire department. If the CO alarm sounds, immediately move to a fresh air location outdoors or by an open window or door. Make sure everyone inside the home is accounted for. Call for help from a fresh air location and stay there until emergency personnel.

What number to call if a carbon monoxide alarm goes off?

Before you return to your home it is very important to call the 24 hour Gas Emergency Number on 0800 111 999 and tell them what has happened and receive safety advice (even if the suspected source of the CO is not a gas appliance).

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.

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.

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 do I know if my house is full of carbon monoxide?

Carbon monoxide is invisible, odorless and tasteless. Inspection helps protect yourself and your family. Install a carbon monoxide detector in your house, and plan to check its battery every time you check your smoke detector batteries.

Can you have carbon monoxide leak without the alarm going off?

Carbon monoxide is a highly poisonous gas that has no colour, taste or smell, making it impossible to detect without an alarm.

How long does it take for carbon monoxide to kick in?

How long does it take to get carbon monoxide poisoning? In high concentrations of carbon monoxide, it can take fewer than five minutes to get carbon monoxide poisoning. Under lower concentrations, it can take an hour to two hours to cause poisoning.

Why do carbon monoxide alarms go off at night?

It is possible to have a carbon monoxide detector going off without any danger present. If you suspect that this is the case, it's important not to ignore it. This could be due to a faulty device, old batteries, or just dust buildup in the unit itself.

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

If your CO alarm stopped beeping after being outside in the fresh air for 10 minutes, you may have a possible carbon monoxide leak in your home. We recommend calling your gas supplier or national emergency gas helpline on 0800 111 999 and await further instruction.

How to clear carbon monoxide from a house?

If no one is feeling symptoms, ventilate the home with fresh air and turn off all potential sources of CO. That includes your oil or gas furnace, gas water heater, gas range and oven, gas dryer, gas or kerosene space heater, and any vehicle or small engine.

What does mild carbon monoxide poisoning look like?

Symptoms of carbon monoxide poisoning

A tension-type headache is the most common symptom of mild carbon monoxide poisoning. Other symptoms include: dizziness. nausea (feeling sick) and vomiting.

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