How To Detect Carbon Monoxide: Warning Signs And Prevention

Home » How To Test For Carbon Monoxide Without A Detector » How To Detect Carbon Monoxide: Warning Signs And Prevention

Maybe your like

Skip to ContentQuizzes
  • Home
  • Random
  • Browse Articles
  • Quizzes & Games
  • All QuizzesHot
  • Love Quizzes
  • Personality Quizzes
  • Fun Games
  • Dating Simulator
  • Learn Something New
  • Forums
  • Courses
  • Happiness Hub
  • Explore More
  • Support wikiHow
  • About wikiHow
  • Log in / Sign up
Terms of Use wikiHow is where trusted research and expert knowledge come together. Learn why people trust wikiHow How to Detect Carbon Monoxide without a Detector PDF download Download Article Explore this Article Sections 1 Signs of a Carbon Monoxide Leak 2 What are the symptoms of carbon monoxide poisoning? 3 Preventing Carbon Monoxide Buildup Other Sections Tips and Warnings Related Articles References Article Summary Co-authored by Hunter Rising

Last Updated: April 3, 2025 Fact Checked

PDF download Download Article X

This article was co-authored by wikiHow staff writer, Hunter Rising. Hunter Rising is a wikiHow Staff Writer based in Los Angeles. He has more than three years of experience writing for and working with wikiHow. Hunter holds a BFA in Entertainment Design from the University of Wisconsin - Stout and a Minor in English Writing. There are 14 references cited in this article, which can be found at the bottom of the page. This article has been fact-checked, ensuring the accuracy of any cited facts and confirming the authority of its sources. This article has been viewed 404,316 times. Learn more...

You may have heard of the risks of carbon monoxide (CO), but how can you check if it’s in your home? Carbon monoxide is an odorless and colorless poisonous gas that’s produced from burning gas or oil, and it can be deadly when it reaches unsafe levels. Even though CO might seem difficult to detect in your home, there are a lot of warning signs and preventative steps you can take to protect yourself. Keep reading for everything you need to know about the signs of carbon monoxide in your home, the symptoms of CO poisoning, and what you can do to prevent buildups.

Things You Should Know

  • 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.[1]
  • 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.
  • Watch out for flu-like symptoms that occur specifically around gas appliances. This can be a sign of carbon monoxide poisoning.[2]

Steps

Section 1 of 3:

Signs of a Carbon Monoxide Leak

PDF download Download Article
  1. Step 1 Black or yellow stains around gas boilers, stoves, or fireplaces. 1 Black or yellow stains around gas boilers, stoves, or fireplaces. Sooty stains or marks around your appliances mean there’s a loose connection and carbon monoxide could be leaking into your home.[3]
    • You may also notice black soot marks on front covers or panels on a gas fireplace.[4]
  2. Step 2 Smoke buildup when you use your fireplace. 2 Smoke buildup when you use your fireplace. If something is blocking your chimney when you burn a fire, the smoke won’t be able to vent out of your home properly. Since smoke can increase the levels of CO in your home, it can become hazardous if you leave the fire to burn.[5]
    • Even when you aren’t burning a fire, a clean chimney will have an upward draft you can feel when you open the flue. If you can’t feel a draft, it’s another warning sign that CO levels could build up.
    Advertisement
  3. Step 3 Yellow flames on gas appliances. 3 Yellow flames on gas appliances. When you use a gas appliance, you’ll normally see blue flames which means all the gas is burning properly. If you see yellow or orange flames, or if burners aren’t fully igniting, it means there’s an issue with the gas and carbon monoxide could build up.[6]
  4. Step 4 Pilot lights blowing out frequently. 4 Pilot lights blowing out frequently. Pilot lights are small flames on furnaces, gas stoves, and water heaters that are always burning to help prevent gas leaks in your home. If you notice that your pilot light doesn’t stay lit or it flickers, it could mean CO has built up in the air around it.
    • If the pilot light flame is blue, it could also be a sign that it’s not burning gas properly and CO is accumulating in the air.
  5. Step 5 Condensation buildup on windows near gas appliances. 5 Condensation buildup on windows near gas appliances. If you notice water droplets on the insides of the windows in a room with a gas appliance, it could mean that it’s not venting outside properly and CO is building up in your home.[7]
    6. Advertisement
Section 2 of 3:

What are the symptoms of carbon monoxide poisoning?

PDF download Download Article
  1. Step 1 Mild CO poisoning has symptoms similar to the flu or food poisoning. 1 Mild CO poisoning has symptoms similar to the flu or food poisoning. When carbon monoxide levels are 50 parts per million (ppm), you’ll start to experience flu-like symptoms.[8] You can tell if you have CO poisoning instead of the flu if you don’t have a fever when you have symptoms. If you feel any of the following symptoms, get to fresh air immediately and contact your doctor so they can treat your CO poisoning.[9]
    • Tension headache
    • Dizziness or vertigo
    • Fatigue or tiredness
    • Confusion
    • Difficulty breathing or shortness of breath
    • Chest pains
    • Stomach pains, nausea, or vomiting
    • Loss of consciousness
  2. Step 2 Multiple people in your household will experience the same symptoms. 2 Multiple people in your household will experience the same symptoms. You’ll notice everyone else you live with, including pets, getting sick around the same time if there’s carbon monoxide accumulating inside. If the symptoms were caused by the flu, one person would get sick before spreading it to someone else.[10]
    • People who spend more time indoors will be the most affected by the symptoms of CO poisoning.
  3. Step 3 Your symptoms will go away when you’re not near a CO leak. 3 Your symptoms will go away when you’re not near a CO leak. Since the carbon monoxide only builds up in enclosed spaces, you might notice your symptoms disappear when you’re not at home. Once you come back, the same symptoms will return.[11]
    4. Advertisement
Section 3 of 3:

Preventing Carbon Monoxide Buildup

PDF download Download Article
  1. Step 1 Install carbon monoxide detectors throughout your home. 1 Install carbon monoxide detectors throughout your home. Choose carbon monoxide detectors that are battery-powered or have a battery backup in case of a power outage, and get at least 1 for each story of your home.[12] Since CO is slightly lighter than air, install the detectors 5 ft (1.5 m) above the floor and within 10 feet (3.0 m) of any bedroom so you can hear the alarm.[13]
    • Put the CO detector at least 15 feet (4.6 m) away from your kitchen or any other cooking appliances.
    • Check or replace the batteries twice a year. After 5–7 years, replace the entire detector unit.[14]
    • When an alarm goes off, quickly leave and get to fresh air and check if you’re experiencing symptoms. Contact emergency services or your utility company to find the source of the leak or what caused the alarm to go off.[15]
    • It usually takes 60–90 minutes for CO detectors to go off when carbon monoxide levels are above 50 ppm. If there are extreme or deadly levels above 330 ppm, then the detector will go off within 2–3 minutes of exposure.[16]
  2. Step 2 Have gas- or oil-burning appliances inspected annually. 2 Have gas- or oil-burning appliances inspected annually. Hire a qualified appliance technician to look at all of your appliances that could potentially leak carbon monoxide, such as your oven, furnace, ventilation system, or water heater. They’ll be able to address any leaks or problems so that you stay safe when you use your appliances.[17]
  3. Step 3 Clean your fireplace and chimney each year. 3 Clean your fireplace and chimney each year. Since soot can build up inside and prevent proper ventilation, take the time to clean your chimney. If you don’t feel comfortable cleaning your chimney by yourself, hire a professional service to come to clean it out for you to ensure the job gets done correctly.[18]
    • Whenever you use your fireplace, make sure you open the flue and wait to close it until the ashes feel cool so smoke can escape.
  4. Step 4 Open your garage door before you start your vehicle. 4 Open your garage door before you start your vehicle. Your vehicle’s exhaust also creates carbon monoxide and it can build up to dangerous levels in your garage. Keep your garage door open to let air flow through and back your car out into the driveway if you leave it idling so there’s no chance of CO accumulating inside.[19]
  5. Step 5 Use gas appliances for their intended purposes only. 5 Use gas appliances for their intended purposes only. Avoid using a gas stove, oven, or dryer to heat a room since it increases the risk of CO exposure and buildup.[20]
  6. Step 6 Avoid using unvented gas appliances in enclosed spaces. 6 Avoid using unvented gas appliances in enclosed spaces. Camping stoves and generators burn gas for power, but they don’t have exhaust vents to guide carbon monoxide outside. Only use these appliances outdoors or in a well-ventilated space with open windows so the carbon monoxide can properly dissipate without building up.[21]
    • Never use an unvented gas appliance anywhere where someone is sleeping.
    • Avoid using unvented gas appliances for longer than 4 hours at a time.[22]
    7. Advertisement

Expert Q&A

Search Add New Question Ask a Question 200 characters left Include your email address to get a message when this question is answered. Submit Advertisement

Tips

  • Average CO levels in your home if you have a gas stove are usually 5–15 ppm. If you don’t have a gas stove, then the range is around 0.5–5 ppm.[23] You’ll notice symptoms of CO poisoning if levels are 70 ppm or higher.[24] Thanks Helpful 0 Not Helpful 0
Submit a Tip All tip submissions are carefully reviewed before being published Name Please provide your name and last initial Submit Thanks for submitting a tip for review! Advertisement

Warnings

  • Infants and people with chronic heart disease, anemia, and respiratory problems are more at risk of CO poisoning.[25] Thanks Helpful 0 Not Helpful 0
  • If you suspect a CO leak in your home, avoid trying to find the source of it on your own so you don’t get CO poisoning. Contact emergency services and let them find the leak.[26] Thanks Helpful 1 Not Helpful 0
Advertisement

You Might Also Like

Detect a Gas LeakHow to Determine if You Have a Gas Leak: Safety Tips & Signs Turn Off Carbon Monoxide AlarmHow to Stop a Carbon Monoxide Alarm & What to Do When It Goes Off For Real Safely Turn off the Pilot Lights on Your Gas StoveHow toSafely Turn off the Pilot Lights on Your Gas Stove Carbon Monoxide Detector BeepingCarbon Monoxide Detector Beeping? Emergencies vs. False Alarms Test a Carbon Monoxide DetectorHow to Test Your Carbon Monoxide Detector (Easy Steps) Test the Air Quality in Your HomeHow toTest the Air Quality in Your Home Reset Carbon Monoxide AlarmHow to Reset and Test a Carbon Monoxide Detector Tell if a Smoke Detector Detects Carbon Monoxide3 Ways to Tell the Difference Between a Smoke and Carbon Monoxide Detector Kidde Carbon Monoxide Detector BeepingWhat to Do If Your Kidde Carbon Monoxide Detector is Beeping Use a Gas StoveHow toUse a Gas Stove Test a ThermocoupleHow toTest a Thermocouple Furnace Wont Turn onWhat to Do If Your Furnace Won't Kick On, According to an Expert Turn Off a Pilot LightHow toTurn Off a Pilot Light Fire Alarm Beeping 3 TimesCommon Reasons Why a Fire Alarm Sounds 3 Times Advertisement

References

  1. ↑ https://www2.hse.ie/conditions/carbon-monoxide-poisoning/
  2. ↑ https://www.cdc.gov/carbon-monoxide/about/index.html
  3. ↑ https://www2.hse.ie/conditions/carbon-monoxide-poisoning/
  4. ↑ https://www.nhs.uk/conditions/carbon-monoxide-poisoning/
  5. ↑ https://www.health.state.mn.us/communities/environment/air/toxins/index.html
  6. ↑ https://www.london-fire.gov.uk/safety/the-home/carbon-monoxide-safety/
  7. ↑ https://www.health.state.mn.us/communities/environment/air/toxins/index.html
  8. ↑ https://www.cpsc.gov/Safety-Education/Safety-Education-Centers/Carbon-Monoxide-Information-Center/Carbon-Monoxide-Questions-and-Answers
  9. ↑ https://www.nhs.uk/conditions/carbon-monoxide-poisoning/
More References (17)
  1. ↑ https://www.health.state.mn.us/communities/environment/air/toxins/index.html
  2. ↑ https://doh.wa.gov/community-and-environment/contaminants/carbon-monoxide
  3. ↑ https://www.cdc.gov/carbon-monoxide/about/index.html
  4. ↑ https://www.epa.gov/indoor-air-quality-iaq/where-should-i-place-carbon-monoxide-detector
  5. ↑ https://www.cdc.gov/carbon-monoxide/about/index.html
  6. ↑ https://www.health.state.mn.us/communities/environment/air/toxins/index.html
  7. ↑ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3649163/
  8. ↑ https://www.cdc.gov/carbon-monoxide/about/index.html
  9. ↑ https://www.epa.gov/indoor-air-quality-iaq/carbon-monoxides-impact-indoor-air-quality
  10. ↑ https://myhealth.alberta.ca/Health/pages/conditions.aspx?hwid=hw193731
  11. ↑ https://my.clevelandclinic.org/health/diseases/15663-carbon-monoxide-poisoning
  12. ↑ https://www.cpsc.gov/Safety-Education/Safety-Education-Centers/Carbon-Monoxide-Information-Center/Carbon-Monoxide-Questions-and-Answers
  13. ↑ https://www.hopkinsmedicine.org/health/conditions-and-diseases/carbon-monoxide-poisoning
  14. ↑ https://www.epa.gov/indoor-air-quality-iaq/carbon-monoxides-impact-indoor-air-quality
  15. ↑ https://www.cpsc.gov/Safety-Education/Safety-Education-Centers/Carbon-Monoxide-Information-Center/Carbon-Monoxide-Questions-and-Answers
  16. ↑ https://doh.wa.gov/community-and-environment/contaminants/carbon-monoxide
  17. ↑ https://www.cpsc.gov/Safety-Education/Safety-Education-Centers/Carbon-Monoxide-Information-Center/Carbon-Monoxide-Questions-and-Answers

About This Article

Hunter Rising Co-authored by: Hunter Rising wikiHow Staff Writer This article was co-authored by wikiHow staff writer, Hunter Rising. Hunter Rising is a wikiHow Staff Writer based in Los Angeles. He has more than three years of experience writing for and working with wikiHow. Hunter holds a BFA in Entertainment Design from the University of Wisconsin - Stout and a Minor in English Writing. This article has been viewed 404,316 times. 26 votes - 88% Co-authors: 23 Updated: April 3, 2025 Views: 404,316 Categories: Featured Articles | Environmental Health Article SummaryX

One of the best ways to detect carbon monoxide is to install a CO detector close to the ceiling on every level of your home. If you don’t have a CO detector, it’s important to know the health symptoms of carbon monoxide poisoning, which include headache, muscle weakness, dizziness, nausea, shortness of breath, confusion, blurred vision, and loss of consciousness. In order to prevent CO accumulation, keep your vents clear of dust and debris, clean your fireplace and chimney, and make sure that ovens are working. To learn how to read your CO detector display, keep reading! Did this summary help you?YesNo

In other languages Spanish Russian Italian French Indonesian Japanese
  • Print
  • Send fan mail to authors
Thanks to all authors for creating a page that has been read 404,316 times.

Reader Success Stories

  • Antoinette Adams

    Antoinette Adams

    Feb 15, 2017

    "This article answered all my questions that I was concerned about regarding carbon monoxide poisoning. (From a very..." more
More reader stories Hide reader stories Share your story If you buy through links on our site, we may earn a commission.

Did this article help you?

Yes No Advertisement If you buy through links on our site, we may earn a commission.Cookies make wikiHow better. By continuing to use our site, you agree to our cookie policy. Hunter Rising Co-authored by: Hunter Rising wikiHow Staff Writer Co-authors: 23 Updated: April 3, 2025 Views: 404,316 88% of readers found this article helpful. 26 votes - 88% Click a star to add your vote 88% of people told us that this article helped them. Antoinette Adams

Antoinette Adams

Feb 15, 2017

"This article answered all my questions that I was concerned about regarding carbon monoxide poisoning. (From a very..." more Virginia Collins

Virginia Collins

Jan 25, 2022

"My gas furnace is old, I am a senior citizen and I can't afford to replace it. Reading the signs of carbon..." more Anonymous

Anonymous

Apr 11, 2017

"This information really helped me learn how to detect CO in a home and the symptoms of CO poisoning. Thank you,..." more Anonymous

Anonymous

Nov 13, 2016

"Learned the signs to look for accumulation of soot and having the heater serviced." Sandra Hinds

Sandra Hinds

Feb 28, 2018

"This was helpful in knowing the warning signs of carbon monoxide poisoning." Share yours! More success stories Hide success stories

Quizzes & Games

Am I Being Gaslighted QuizAm I Being Gaslighted QuizTake QuizOCD TestOCD TestTake QuizDepression TestDepression TestTake QuizBrain Fog TestBrain Fog TestTake QuizDo I Need Glasses QuizDo I Need Glasses QuizTake QuizWhy Am I So Bloated QuizWhy Am I So Bloated QuizTake Quiz

You Might Also Like

Detect a Gas LeakHow to Determine if You Have a Gas Leak: Safety Tips & SignsTurn Off Carbon Monoxide AlarmHow to Stop a Carbon Monoxide Alarm & What to Do When It Goes Off For RealSafely Turn off the Pilot Lights on Your Gas StoveHow toSafely Turn off the Pilot Lights on Your Gas StoveCarbon Monoxide Detector BeepingCarbon Monoxide Detector Beeping? Emergencies vs. False Alarms

Featured Articles

Text Yourself: Fake Text Messages, Reminders, and MoreHow to Text Yourself: Fake Text Messages, Reminders, and MoreAccurate Omegaverse Quiz: 100% GuaranteeAccurate Omegaverse Quiz: 100% GuaranteeThe Hardest & Most Difficult Riddles for AdultsThe Hardest & Most Difficult Riddles for Adults Be More Spontaneous and Enjoy Life to the FullestHow to Be More Spontaneous and Enjoy Life to the FullestImprove Your PersonalityHow toImprove Your PersonalitySigns You Were Meant For Greatness (Quiz)Signs You Were Meant For Greatness (Quiz)

Trending Articles

How Sexual Am I QuizHow Sexual Am I QuizHow Much Do I Mog QuizHow Much Do I Mog QuizWho Is Secretly Crushing On Me Right Now QuizWho Is Secretly Crushing On Me Right Now QuizAccurate IQ Checker Quiz: How Smart Am I?Accurate IQ Checker Quiz: How Smart Am I?Will I Ever Find Love QuizWill I Ever Find Love QuizCan We Guess How Tall You Are QuizCan We Guess How Tall You Are Quiz

Featured Articles

210+ Shower Thoughts: Funny, Deep, Weird & Mind-Blowing210+ Shower Thoughts: Funny, Deep, Weird & Mind-Blowing Meet Gay People Without a Dating AppHow to Meet Gay People Without a Dating AppCute, Thoughtful & Romantic Messages to Wish Her a Good Day at WorkCute, Thoughtful & Romantic Messages to Wish Her a Good Day at WorkWhat Movie Should I Stream QuizWhat Movie Should I Stream QuizWhat Does the Term "Femboy" Mean?What Does the Term "Femboy" Mean?40+ Fun & Exciting Group Game Ideas to Play with 20+ People40+ Fun & Exciting Group Game Ideas to Play with 20+ People

Featured Articles

11 Things to Do If You’re Connected to Wi-Fi But Have No Internet11 Things to Do If You’re Connected to Wi-Fi But Have No InternetThe Ultimate List of Funny Nicknames for Your CoworkersThe Ultimate List of Funny Nicknames for Your CoworkersWhich Five Nights at Freddy's Character Am I QuizWhich Five Nights at Freddy's Character Am I QuizBest Haircuts for Men with Round Faces (& How to Style Them)Best Haircuts for Men with Round Faces (& How to Style Them)What Is the Chubby Body Type? Plus, How It Compares to Other Body TypesWhat Is the Chubby Body Type? Plus, How It Compares to Other Body TypesDo I Have an Innocent Face QuizDo I Have an Innocent Face Quiz

Watch Articles

Marinate Chicken: 4 Recipes and a Step-By-Step GuideHow to Marinate Chicken: 4 Recipes and a Step-By-Step GuideClean Shower TileHow toClean Shower TileDo Oblique CrunchesHow toDo Oblique CrunchesSimple Ways to Riffle Shuffle and Bridge Playing CardsSimple Ways to Riffle Shuffle and Bridge Playing CardsMake Black CoffeeHow toMake Black CoffeePlant a Seed in a PotHow toPlant a Seed in a Pot

Trending Articles

Do I Attract the Male Gaze or the Female Gaze QuizDo I Attract the Male Gaze or the Female Gaze QuizHow Weird Am I QuizHow Weird Am I QuizFunny Numbers to Call When You’re Bored or Want to Prank SomeoneFunny Numbers to Call When You’re Bored or Want to Prank SomeoneThe 26 Different Types of Women in Psychology, Dating, & LiteratureThe 26 Different Types of Women in Psychology, Dating, & LiteratureMental Illness TestMental Illness TestWhat Type of Person Do I Attract QuizWhat Type of Person Do I Attract Quiz

Quizzes & Games

How Good Are My Survival Instincts QuizHow Good Are My Survival Instincts QuizTake QuizWhat's Your Red Flag QuizWhat's Your Red Flag QuizTake QuizCan You Spot The False Climate Claims QuizCan You Spot The False Climate Claims QuizTake QuizAre My Hormones Imbalanced QuizAre My Hormones Imbalanced QuizTake QuizIs My Relationship Toxic QuizIs My Relationship Toxic QuizTake QuizAm I In Love QuizAm I In Love QuizTake Quiz wikiHow
  • Categories
  • Health
  • Environmental Health
wikiHow Newsletter You're all set! Helpful how-tos delivered toyour inbox every week! Sign me up! By signing up you are agreeing to receive emails according to our privacy policy.
  • Home
  • About wikiHow
  • Experts
  • Jobs
  • Contact Us
  • Site Map
  • Terms of Use
  • Privacy Policy
  • Do Not Sell or Share My Info
  • Not Selling Info
  • Contribute

Follow Us

×

Don’t miss out! Sign up for

wikiHow’s newsletter

Subscribe You're all set! X --576

Tag » How To Test For Carbon Monoxide Without A Detector