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

Author: Prof. Arvel Eichmann Jr.  |  Last update: Thursday, May 29, 2025

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.

Who to call if carbon monoxide alarm goes off?

CO detectors are very sensitive and designed to alert occupants before CO reaches dangerous levels. If your detectors go off, call 911 and evacuate the home. Be sure to notify them if anyone in the house is experiencing flu-like symptoms.

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.

Do you call 911 if the carbon monoxide alarm goes off?

Install a CO detector:

If your CO detector goes off and you feel ill, leave the house and call 911 or the local fire department. If you do not feel ill, push your detector's reset button. If the alarm goes off again after a few minutes, open the windows, leave the house and call 911 or the local fire department.

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 to Do if Carbon Monoxide Alarm is Going Off

Do you get charged for calling 9-1-1 for carbon monoxide?

There is no per-call charge for calling 9-1-1. However, EMS/ambulances dispatched through 9-1-1 may charge for taking someone to the hospital; this is a separate ambulance charge, not a 9-1-1 charge.

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 carbon monoxide alarm goes off but 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 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.

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 tell if carbon monoxide is leaking?

What Are Signs of Carbon Monoxide in Your Home?
  1. Yellow or orange flames coming out of your gas appliances instead of the usual blue flame.
  2. Dark and sooty staining on or around gas appliances.
  3. Pilot lights that frequently blow out.
  4. Increased condensation on windows.
  5. Solid fuel fires burn much slower than usual.

Will a carbon monoxide alarm go off again if you silence it?

If you “shut it off” it will not be working, so will not detect carbon monoxide. If you reset it, it will activate again if carbon monoxide is detected, as long as the battery/power supply is within normal operating limits. A low battery may cause the alarm to “fail safe” and activate to notify that it needs replacing.

What to do if you hear a carbon monoxide alarm?

What to do if a carbon monoxide alarm goes off. If your carbon monoxide alarm is beeping, immediately get out of the building and call the relevant helpline for the fuel type. The gas emergency helpline is 0800 111 999. Call a registered engineer to check all your fuel-burning appliances.

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.

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.

Can I call the fire department to check for carbon monoxide?

Yes, the fire department can check for carbon monoxide. If you suspect the presence of carbon monoxide in your home or building, it's essential to act quickly. Evacuate the area, ensure everyone's safety, and call your local emergency services or fire department.

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.

Is it safe if carbon monoxide alarm goes off?

If the alarm sounds, vacate the house. Then, it's best to call 911 or the fire department to come out and test for the source of carbon monoxide. Once they've identified what is causing carbon monoxide to be released in your home, you'll need to contact a licensed professional to service the offending 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.

What else can trigger a carbon monoxide detector?

Things That Trigger Carbon Monoxide Detectors
  • Malfunctioning gas appliances–Any gas-burning appliance can emit CO if it's not getting the correct gas-to-air ratio. ...
  • Air leaks–Leaky air ducts can pull carbon monoxide into your home from vented gas appliances like dryers, water heaters, and furnaces.

Do you call 911 for carbon monoxide?

Call 911 and report what is happening. Immediately leave your residence and wait for the fire department to arrive. Once there, we will send in a team with special monitoring equipment that will take air readings and determine the next appropriate action.

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

4 beeps and a pause: This means that there is carbon monoxide in the air and you should seek fresh air immediately and call 911.

Should you open windows if the carbon monoxide alarm goes off?

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. CO could build up again once you're inside.

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