A Carbon Monoxide detector is an excellent safety measure to protect you and your family against carbon monoxide (CO) poisoning. CO is often regarded as a “silent killer,” as you will hardly notice its presence in an environment until it’s too late.
Carbon monoxide detectors help keep you safe though they fail or malfunction, so what should you do when you notice that your carbon monoxide detector went off before stopping?
What could be the reason? What could it mean? Should you call 911? Does it mean that you are in danger? Is it a false alarm?
This article will address all FAQs regarding your carbon monoxide detector. Reasons why it could go off and stop, what to do in such a situation, and other CO concerns issues.
Why Did My Carbon Monoxide Detector Go off and Then Stop?
If you’ve experienced your carbon monoxide detector going off and then stopping, it should be a significant cause for concern and should not be ignored.
There are several reasons why this is happening; your detector could have low batteries, be broken, the sensors may have malfunctioned, or it could have detected CO in the surrounding.
There is a handful of speculation! Try to figure out the number of times the detector beeped before stopping to help respond appropriately.
Below is a discussion of reasons why your carbon monoxide detector went off and then stopped:
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Low Battery

Once your CO detector goes off, it is wise to troubleshoot and examine the batteries in the detector. The CO detector will stop working when its lifespan ends and the battery levels are low.
This is why some homeowners would connect their CO detectors directly to the grid to avoid frequent battery replacement hassle.
If your carbon monoxide detector is battery-operated, it will beep three times, but the red lights will not blink. This is an indicator that you need to replace the batteries.
Also, if the detector keeps beeping after every 30 to 60 seconds, it signifies a malfunctioned sensor that needs immediate replacement.
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Life Span of Your Smoke Detector
Carbon Monoxide detectors are designed to last about seven years, while others may last up to ten years. However, keeping the detector for up to 10 years is not recommended as it may not offer you the protection you need in times of danger.
This is because the sensors will wear out after a long service life and may not signal you in times of danger. It is wrong to assume that the detector works fine as it makes you more susceptible to this hazardous gas.
The sensors may fail to work despite having fully functional batteries, thus unable to function. Therefore, next time your CO detector goes off, yet your batteries are still new, check the date of manufacture. It may have reached its end of life.
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Damaged or Out-Of-Service Detector
Your carbon monoxide detector may start beeping erratically if your device is worn out, expired, or broken. Rising CO levels do not stimulate the beeps in the surrounding; instead, the damaged parts or faulty sensors may cause the beeping.
If you troubleshoot and suspect this is the cause of the beeping, consider replacing the whole system for optimum protection.
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Fire In the House
Your carbon monoxide can go off because of a fire in the house. Homeowners are advised to integrate all sensors and connect them with the grid for a constant provision of electricity. This is a safer option because all the detectors in the house will go off once one notices that the CO levels are rising.
The detectors going off will signal that something is wrong and begin troubleshooting immediately. Identify the alarm’s source or immediately empty the premises. Get everyone out of the home until emergency help arrives.
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Sudden Changes In the Room Temperature
Temperature fluctuations within the location of your CO detector could also cause it to go off and stop. The sudden temperature changes could be a result: of a sudden hot wind blowing into your air conditioner, a compact home that’s poorly ventilated, the kitchen heat, change in the temperature of your appliance and thermostat temperature.
Such factors demand you choose a location to install your carbon monoxide detector. Ideally, you are advised to install it away from regular CO emission plates, failure to which will result in false alarms, which may drive you nuts.
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Improper Installation or Maintenance
Improper carbon monoxide detector installation could also trigger it to go off unnecessarily. For instance, you could have located it close to furnaces, the kitchen, a hot shower bathroom, or any other appliance that emits CO gas.
Consider hiring a qualified technician to calibrate your carbon monoxide detector to avoid such mistakes properly.
- False Alarm as a Result of Dust In the Sensors’ Chamber
How frustrating is it to discover that your household’s CO alarm that has caused panic is false? Your CO alarm sound could cause unimaginable stress and panic.
Avoid this by practicing frequent maintenance of your CO detector. One way of doing this is ensuring that you do not install your detector in areas frequented by dust and humidity. These are the biggest triggers of the device.
- Error Codes from Previous Instances got Triggered
Your carbon monoxide detector can go off because of the log records of previous triggers. The sensor is designed to maintain the logs, which sometimes may cause problems.
The CO detector can go off when changing the batteries. It will go off and blink three times before stopping due to previous instances.
Resolve such situations by pressing the sensors about 5-10 times, which will contain the erratic beeping.
- Improper Insertion of the Battery
If you improperly insert the batteries, your smoke detector can release high-pitched and annoying beeps. It could continue to beep for a while until you respond to it.
Resolve this problem by detaching the batteries from the device by pulling the tabs. This way, the CO detector will not be powered, hence will silence.
However, the device will still warn you about the need to insert new batteries. Another way of solving such an issue is to remove the pull tab and close the batteries’ cover appropriately to ensure they fit perfectly. This will prevent unnecessary beeping of the detector.
- Wrong Type of Carbon Monoxide Detector
Your CO detector could also beep if it is incompatible with the type of premises you are in. For instance, CO detectors installed in a caravan, tent, boat, or living quarters of a horsebox must have a kitemark BS EN50291-2.
If the alarm is tested as BS EN50291-2, it can only be used in home environments. Using it in other surroundings, such as camping or caravanning, might beep due to the incompatibility.
- Presence of a Heavy Tobacco Smoker In a Room
If a person is smoking tobacco in a poorly ventilated room, the smoke could also trigger your CO detector. This happens on rare occasions.
- The Location of Your Home
The location of your premise highly affects how your carbon monoxide detector functions. For instance, homes closely located on jam-packed roads experience higher levels of CO within the areas, especially when the windows are open. This is because traffic fumes may penetrate the house, triggering the CO alarm.
- The Type of Battery Chargers
Lead acid battery chargers usually produce hydrogen gas while charging. This gas can set off the carbon monoxide detector.
Additionally, freshly screeded floors produce gas that sets off your CO detector.
NOTE: CO gas is extremely dangerous. The gas will silently sneak into your house without warning. It will build up in closed spaces, leading to a potential health risk or a fatal outcome like death.
The unnecessary beeping of the detector is not so bad after all. Consider it as a guardian angel who has given you a new chance to live😊.
What To Do When Carbon Monoxide Alarm Goes Off and Then Stops?
Does it get any scarier? Knowing that there is a harmful gas leaking in your house that could potentially send you and your loved ones to an early grave? This must be what it feels like once you hear the carbon monoxide detector going off. While the beeping can be pretty alarming, there is enough time to act accordingly instead of panicking. The alarm’s sound is an indicator that allows you to take prompt action.
The mayo clinic reports that CO is a deadly gas, even if inhaled in small amounts. Therefore, you must pay attention to the insistent sounds.
Below is a discussion of the things you need to do once your CO detector goes off and then stops:
- Move to an Outdoor area with Fresh Air.
The first action you are expected to take is to vacate the premise where CO could be coming from and rest around an area with fresh air. Don’t forget your loved ones and pets as well.
If you cannot leave the premise, open up all the windows and doors. While this may not stop the carbon monoxide poisoning, it slows down the process. By opening up the windows and doors, you will be ventilating the space, diluting the CO concentration within the environment.
- Dial 911
The affected area’s residents should immediately dial 911 (this is the standard emergency number). Tell them that your carbon monoxide detector has gone off so that they send you emergency help in the shortest time possible.
- Avoid Going Back into the House Even After the Alarm Stops.
You may be tempted to go back in after the alarm stops sounding because, if it’s silent, it means there is no more CO gas in the air, right? Please don’t fall into this temptation.
You may open the doors and windows so that the CO in the surroundings dissipates. However, it is still dangerous because you are unsure if the machine that triggered the alarm has stopped producing the poisonous gas. The gas could build up again when you are still in the house.
NOTE: Once emergency help arrives, the responders will examine the source of the gas leaking into your home. It could be anything from a gas-powered appliance such as a stove, furnace, or water heater.
Once they note the source of the problem, the responders will turn it off and ventilate the space using high-powered fans. This will help remove the poisonous gas, replace the fresh air and reseal the area. They will also run a test to ensure that they have found the only emission of CO. If the carbon monoxide readings are back to normal, you will be allowed back into the house.
Carbon monoxide gas is described as a silent killer since the human senses can hardly detect it. However, according to Healthline, you should watch out for symptoms such as headache, nausea, and vomiting, as they could indicate that you are experiencing carbon monoxide poisoning. Other symptoms include dizziness, fatigue or weakness, loss of consciousness (passing out), lightheadedness, blurry visions, sleepiness, loss of muscle control, increased heart rate, chest tightening, confusion, and disorientation.
If you suspect anyone within your household (or even yourself) has CO poisoning, go to the nearest emergency room.
NOTE: Even though the emergency responders may have cleared the CO presence in your home, you will still have to take more safety measures. This includes calling in a qualified and licensed technician to fix the problem’s source permanently. Failure to do so increases the risk of a reoccurrence once you turn the device back on.
As we have discussed earlier, sometimes your carbon monoxide detector could go off because it is a false alarm. Unfortunately, this is not a relief. The false alarm could be life-threatening because it would, over time, dull your response to the emergency. Consider installing new batteries or replacing the alarm system once it goes off.
Now that we know what to do once we hear our carbon monoxide detector goes off, let us also know where this gas comes from. It will help us in taking necessary precautions for our safety.
Where Does Carbon Monoxide Come From?
Carbon monoxide gas is released whenever carbon monoxide fuels like a natural gas burn. The CO is produced as a by-product of incomplete combustion. Fuels such as wood or propane are considered low-carbon fuels since they produce lower levels of carbon monoxide into the air when compared with natural gas.
Why is it vital to know the amount of CO levels? We measure the carbon monoxide levels in parts per million (ppm). Different natural gas, machines, or fuels produce different CO levels. For instance, starting your car engine can produce approximately 80,000 ppm in the first few minutes. The National Fire Protection Association (NFPA) asserts that air levels of 400 ppm can reflect on your body through severe headaches and sickness within an hour or less.
You may question why you don’t get sick while in your car, yet the engine produces high CO levels. This is because whenever you start your car outside, the harmful CO molecules have room to disperse and are diluted with the fresh air within your surroundings.
Side Note: Avoid starting your car in an enclosed space, such as in your garage with the door closed. This will breed an environment for CO build-up, which may be poisonous if not detected on time.
Your house appliances such as gas ranges, boilers, water heaters, ovens, grills, dryers, furnaces, and wood-burning stoves burn fuel which can also cause CO build-up within your home.
This explains why the state’s safety organizations have established standard rules on the amount of CO your appliances can emit. For instance, stoves are not allowed to emit more than 800 ppm of CO.
Also, if you leave your appliance on for too long, they emit tiny amounts of CO into the atmosphere till it reaches dangerous levels. The appliances can also emit CO gas if they are poorly installed.
Instructions About Carbon Monoxide Detector
Doubtlessly, carbon monoxide is a crucial life-saving device that would protect you from exposure to CO, one of the deadliest gas ever. You’d want to follow the recommended instructions to the latter for optimum protection.
The National Fire Protection Association (NFPA) recommends installing a CO detector in every room in your house. It also gives directions on the specific locations of the CO detector in your house. Accordingly, you are advised against locating your carbon monoxide detector in such places as the garage, kitchen, dusty or dirty, humid or greasy areas. Also, avoid installing them in areas under direct sunshine exposure, extreme temperatures, crawl spaces, unfinished attics, and an uninsulated ceiling. These locations may trigger unnecessary beeping, which may be nerve-wracking.
Also, avoid installing the CO detector close to appliances that constantly emit CO gas. Doing so will result in the device constantly going off. Installing the CO detector in the bathroom is a no-brainer. The humidity inside the bathroom will trigger the CO sensors. The same applies to installing it inside the kitchen.
Therefore NFPA recommends installing your CO detector in sleeping areas and areas where you spend most of the time, like the living room.
Reminder: Don’t forget to install your CO detector near the stairs, in the basement, and on every level of the house. Since you can link all the devices, it will ensure that when one alarm goes off, it will signal and trigger the rest, thus alerting you that something is wrong.
The life span of a CO detector is estimated to be between 5 to seven years. Therefore, using your device after this period will make you vulnerable as the sensors may malfunction. Also, consider replacing the batteries after every one or two months.
How Long Will a Carbon Monoxide Alarm Go Off For?
The time pattern of the beeping sound of the carbon monoxide detector signifies different issues. For instance, if your device’s battery is low, it will produce a shirt chirp after every minute.
If there are dangerous CO levels within the environment, then the CO detector will beep four or five times in a row after every four seconds. Understanding these patterns is essential as it prevents you from mistaking dangerous CO levels for a low battery in your device.
Does a Carbon Monoxide Detector Go off Continuously?
A carbon monoxide detector will not always go off unless there’s a risk of increased CO levels or fires. This is the whole point of having an alarm, isn’t it? They should sound only when necessary and alert you in critical situations.
What Level Triggers a Carbon Monoxide Detector?
The response time for your carbon monoxide alarm will vary depending on the level of CO concentration in the air. For instance, an alarm will sound after three and a half hours of continuous CO exposure on a 50 ppm level. It will sound within eight minutes if the CO exposure level is 400 PPM.
The carbon monoxide exposures usually range in the following levels:
- Low level: 50 PPM and under
- Middle level: ranges between 51 PPM and 100 PPM
- High level: Greater than 101 PPM if no one notices any symptoms.
- Dangerous level: this is anything higher than 101 PPM if one experiences the symptoms of carbon monoxide poisoning.
Different levels of exposure will set off your alarm after different time frames.
40 PPM will sound your alarm after a 10-hour exposure
50 PPM will ring the alarm after an eight-hour exposure
70 PPM levels will set off the alarm after 1 to four hours.
150 PPM levels will have your alarm ringing after 10 to 15 minutes
A 400 PPM level will sound your alarm within four to fifteen minutes.
Important Reminder! Leave your home immediately once you start experiencing symptoms of carbon monoxide poisoning, and call 911 soon as the CO alarm sounds.
The Occupational Safety and Health Administration (OSHA) allows a maximum of 50 PPM concentration of CO exposure for healthy adults in any 8 hours.
At 200 PPM level, you will start experiencing slight headaches, fatigue, dizziness, and nausea for about two to three hours.
At 400 PPM CO level, you will experience frontal headaches within an hour or two. It can become fatal after three hours.
At 800 PPM exposure, there will be dizziness, nausea, and convulsions within 45 minutes. One may also pass out within two hours. In this amount, potential death will occur within two to three hours of CO exposure.
At 1600 PPM, you will experience headaches, dizziness, and nausea within a 20-minute exposure, and death will occur within an hour.
What Does a Dying Carbon Monoxide Detector Sound Like?
We’ve mentioned the possible cause for the beeping of your carbon monoxide detector, and one of them is a complete life span. You can check your device’s manufacture and expiry date to determine whether your detector is reaching its end of life. Alternatively, you can assess the different types of beeps and chirps to inform you of the problem with your device.
If the alarm beeps five times after every minute, it signifies that your CO detector is dying and needs to be replaced ASAP.
If it beeps four times and then pauses, this is an EMERGENCY as it signifies the presence of carbon monoxide within the area. Immediately move to an area with fresher air and call 911.
One beep after every minute indicates that the device has a low battery that needs replacement.
Installing a carbon monoxide detector is the safest way to protect yourself and your family from CO poisoning, especially during winter. It’s a period when most people want to stay indoors and close the doors and windows while they turn on the heating appliances to keep them warm.
Final Thoughts
Installing a carbon monoxide detector is an applaudable safety measure. It will protect you by sounding an alarm soon as they sense a certain amount of CO over time. However, the sound could cause panic and distress, which usually signifies a life-threatening situation. So, what does it mean when
Carbon Monoxide Detector Went Off Before Stopping?
The carbon Monoxide detector will go off and then stop once they detect CO build-up in the surrounding. Sometimes they will beep as a false alarm due to factors such as temperature fluctuations, dust, battery death, or when the device is reaching its end.
Ensure that you troubleshoot and determine the cause of the beeping and act promptly.
I hope this article was insightful! What else would you like to know about Carbon Monoxide Detectors? Please inform us in the comment section.