Carbon Monoxide Detector Went Off Twice Then Stopped [Explained]

Carbon detectors are a must-have safety device for any home. Modern CO detectors have more features than older models and updated signal commands. For this device to be useful, you need to understand the warning signals.

Not all signs and signals might be common to you. For example, what if your carbon monoxide detector went off twice then stopped?

The carbon monoxide detector ringing twice and then stopping means a sudden rise in CO. The air in your home has an alarming level of carbon monoxide. Thus, you need to evacuate from your home soon and call the local emergency service. 

That’s the highlight of our today’s discussion. If you wish to know more join us in the full discussion.

Let’s begin!

Why Would CO Detector Ring Twice & Stop?

Why Would CO Detector Ring Twice & Stop

Your carbon monoxide detector triggering twice before stopping means a sudden rise in CO. The detector probably sensed an abrupt increase of CO in the air. 

In such cases, you should leave the room where the detector is placed. Also, open up the windows in all rooms to let air in and ensure proper ventilation.

Now, don’t confuse the triggering alarm with the beeping sound. Because if the CO detector beeps twice before going off means something else.

If the CO detector beeps twice every 30 seconds then it’s a reminder to replace it. Because it may have reached its lifetime. CO detectors last about 5-7 years. It won’t work properly after it reaches the expiration time.

To check for the expiration date, look at the label on the CO detector. It’s usually at the back or on the side of the detector. If it has not yet approached its expiration date, the two beeps may mean something else.

It could be an internal malfunction that is causing the beeping sound. Change the battery to see if the problem goes away. Also, read the user’s manual to see if there are any instructions on it.

CO detectors with clogged sensors often make false alarms. Make sure to clean the CO detectors once in a while. It’s a part of regular maintenance. 

If nothing works then it may have to be replaced. But consult with a technician before discarding it as an expert might be able to solve it. 

What To Do If CO Alarm Goes Off?

co alarm goes off what to do

Carbon monoxide is a poisonous substance that can even cause death. Every year, many people are killed by carbon monoxide poisoning. So, if your CO detector rings, it should be taken seriously.

CO detectors either beep 4 or 5 times to warn about CO presence in your home. But depending on the model, the signals can be different. So, if it beeps more than once, you should take it as a warning.

The following are the next steps to take if your CO detector alarm is ringing.

Step-1: Move Outdoors

If the carbon monoxide detector rings prepare to move outdoors. But before that, ventilate your home. Open up all the windows and quickly evacuate. 

But if you feel nauseous or short on breath, then evacuate first. Don’t waste time opening the windows.

Step-2: Call The Local Emergency Service

Call the local fire department or the nearest emergency number (911). Meanwhile, make sure that all your family members have evacuated from the house.

Check to see if the others have also left the building. If someone is missing, do not re-enter to look for them. Instead, tell the emergency services about them. They will handle all the others.

For situations like this, always keep an evacuation plan ready beforehand. It’ll come in handy in fire emergency situations like when the fire alarm makes whoop whoop sound.

Step-3: Inspect For CO Leaks

After the emergency passes, you’d have to conduct an inspection for the carbon monoxide leak. A specialist must conduct the inspection. to pinpoint the cause of the leakage.

Carbon monoxide is generated from several sources in your home. For example-

  • Fireplaces
  • Chimneys or furnaces
  • Cigarette smoke
  • Stoves for wood burning
  • Generators
  • Boilers
  • Central heating system
  • Gas rangers
  • Ventilation systems

Although these sources are harmless, CO leakage happens when they are damaged or installed improperly. Incorrect use of these appliances can also be a reason.

CO poisoning is more common in winter. People tend to keep the windows closed and use the heat appliances more. For example, imagine if a chimney gets blocked by snow. 

The smoke will enter the home instead of it getting released outside. So, be careful about using these appliances.

Step-4: Schedule CO Test Occasionally

Even though CO detector alarms are to be taken seriously, there are cases of false alarms. If the detector is not checked for a long time, false alarms can happen.

That’s why they need regular inspections. You can conduct one with the fire alarm inspection. The cost of fire alarm inspection isn’t much. The fire alarm inspection might include the CO detector inspection as well.

If the CO detector is plugged into an outlet, it needs to be checked once a month. Those that are battery-operated, need battery replacement once a year. 

A scheduled inspection will tell you all the changes and fixes the system may need.

Symptoms Of Carbon Monoxide Exposure

When left in the carbon monoxide for long, some symptoms will start to appear. Such as-

  • Headache
  • Fatigue
  • Drowsiness
  • Shortness of breath
  • Impaired judgment
  • Low blood pressure
  • Confusion
  • Chest pain
  • Rapid heartbeat
  • Nausea and vomiting
  • Feeling weak
  • Muscle pain
  • Blurred vision

In case of severe CO poisoning, people can lose consciousness along with muscular coordination. It can even lead to death.

What To Do If Someone Has Carbon Monoxide Poisoning?

If you suspect someone to have CO poisoning, send them to doctors immediately. But instant medical attention is needed. Here’s what you can do-

  • Move the person into the fresh air and call 911. If the person is unconscious, first check for any injuries before transporting him.
  • If the individual is not reacting or is not breathing properly, you may have to perform CPR.
  • Continue giving CPR until the person starts to breathe again.
  • Hand him over to the medical staff.

How To Reduce Carbon Monoxide In Home?

Preventing CO formation in your home is the best way to avoid CO exposure. Here’s how you can prevent it.

Keep Fireplaces & Furnaces Clean:

Make sure the fireplace chimney or the furnace in your home isn’t clogged. If the fume gets blocked on the exit path, it enters the house instead. 

Especially for wood fireplaces, the chimney must not be blocked by any object. For gas fireplaces, you don’t need to worry about the chimney. Since, chimney for gas fireplace is not needed.

Before starting a fire, maintain the fireplace flue damper. It should be kept open until there are no flames and the ashes turn cold.

Don’t Let Your Car Idling In Closed Garage:

Never leave your vehicle idling in the garage. It raises the CO level in the air. Although garages are usually open places the CO can still seep into your home through the garage. 

Service The Heating Appliances:

Damaged or old heating appliances form carbon monoxide in the home. So, make sure to service them on occasion. Keep the house ventilated properly. 

Also, ensure that heating appliances are used properly.

Avoid installing Generator Indoors:

Generators also produce carbon monoxide. So, they should be equipped far away from your house. If you need one, make sure to install it around 20 feet away from windows.

Frequently Asked Questions (FAQs):

What level of carbon monoxide is dangerous?

70 ppm of carbon monoxide or a higher amount of CO is dangerous. Above this level, people experience headaches, fatigue, and nausea. At 150-200 ppm concentrations, people lose consciousness and can even die. The permissible amount of CO in the air is about 50 ppm at maximum.

What other gases can set off a carbon monoxide detector?

Low-quality CO detectors can be set off by other gases like hydrogen cyanide, hydrogen sulfide, and nitrogen dioxide. It can also be set off by a large amount of fumes from burning petrol. Or the vapor of ethyl, isopropyl alcohol, acetylene, methyl, dimethyl sulfide, etc.

Can humidity set off carbon monoxide detector?

Yes, humidity can trigger the carbon monoxide detector. The detector collects the humidity around the sensor and this leads to a false alarm. High moisture content in the air can also cause corrosion to the sensor. Your home’s humidity level should be anywhere from 30 and 50%.


Now you know why your carbon monoxide detector went off twice then stopped. We hope you found the information useful. 

Consult a professional before making any changes to your CO detector. Also, don’t forget about the warranty if you need a replacement. 

Stay safe!