Many companies featured on Money advertise with us. Opinions are our own, but compensation and
in-depth research may determine where and how companies appear. Learn more about how we make money.

Published: Apr 29, 2024 6 min read

More than 400 people die and an additional 100,000 go to the emergency room in the U.S. each year for accidental carbon monoxide poisoning, according to the Cleveland Clinic. Scarily, many things in our homes can produce the deadly gas.

Keep reading to learn more about carbon monoxide, including what can cause it to build up in your home and how to prevent it.

Table of contents

Ads by Money. We may be compensated if you click this ad.AdAds by Money disclaimer
Smart home security every second with ADT
ADT helps protect your home and family 24/7 with professional monitoring and smart solutions. Select your state and get a free quote today.
HawaiiAlaskaFloridaSouth CarolinaGeorgiaAlabamaNorth CarolinaTennesseeRIRhode IslandCTConnecticutMAMassachusettsMaineNHNew HampshireVTVermontNew YorkNJNew JerseyDEDelawareMDMarylandWest VirginiaOhioMichiganArizonaNevadaUtahColoradoNew MexicoSouth DakotaIowaIndianaIllinoisMinnesotaWisconsinMissouriLouisianaVirginiaDCWashington DCIdahoCaliforniaNorth DakotaWashingtonOregonMontanaWyomingNebraskaKansasOklahomaPennsylvaniaKentuckyMississippiArkansasTexas
Get Started

What is carbon monoxide?

Carbon monoxide (or CO) is a colorless and odorless gas that is undetectable to humans. Only a few minutes of exposure to dangerous levels of CO could lead to death or severe health consequences.

According to the Centers for Disease Control and Prevention (CDC), carbon monoxide poisoning symptoms often appear similar to flu symptoms, including the following:

  • Headache
  • Dizziness
  • Weakness
  • Upset stomach
  • Vomiting
  • Chest pain
  • Confusion

You could still be exposed to unsafe levels of carbon monoxide without experiencing the above symptoms. Knowing what can cause CO poisoning and how to prevent it is essential.

How does carbon monoxide build up in a house?

Carbon monoxide can build up in your house when a fuel-burning appliance or system malfunctions causing a leak, isn’t used correctly or isn’t properly vented outside your home. Enclosed spaces (such as your home) can cause high levels of carbon monoxide to build up quickly. The gas is produced when there’s insufficient oxygen, leading to the incomplete burning (or combustion) of carbon.

The systems, appliances, tools and other machines in your home or garage that burn natural gas, propane, oil, kerosene, charcoal, wood and coal can produce carbon monoxide in their exhaust. Common sources of carbon monoxide include the following:

  • Gas stoves
  • Gas, propane, kerosene or charcoal grills and camp stoves
  • Non-electric space heaters
  • Heating systems (furnaces, boilers and water heaters)
  • Clothes dryers
  • Vehicle engines (all gas-powered cars and boats)
  • Gas-powered tools
  • Generators
  • Fireplaces and wood stoves
  • Other machines that use gas-powered engines

What to do if your carbon monoxide detector goes off

If your carbon monoxide detector goes off, it’s important to exit your house to get fresh air immediately. Call 911 once you’re outside.

Look for symptoms of carbon monoxide poisoning in you and your family, including dizziness, lightheadedness and nausea. For more assistance, call poison control at 1-800-222-1222.

How to prevent carbon monoxide poisoning in your home

Carbon monoxide is a silent killer — you can breathe it in without even knowing until it’s too late. Since you can’t detect the gas yourself, installing carbon monoxide detectors in your home is crucial. They can save your life.

The U.S. Environmental Protection Agency (EPA) suggests having a detector on every floor of your home. Be sure to follow the installation instructions provided by the detector’s manufacturer. This includes cleaning and testing your detectors as recommended and promptly replacing dead batteries.

For complete home security, incorporate CO detectors into one of the best home security systems.

Beyond installing detectors, there are best practices you can follow when using appliances, tools and other machines to prevent carbon monoxide poisoning.

Fuel-burning systems, appliances and tools

1. Hire an HVAC technician to service your heating system every year.

2. Hire a qualified technician to service your appliances every year.

3. Don’t use your gas range to heat your house.

4. Don’t use outdoor appliances and machines — such as generators, grills, tools and more — inside your home or garage.

5. Make sure your wood-burning stove or fireplace is properly ventilated with the flue open. Have these serviced every year.

6. When using a generator, keep it outside and 20 feet away from your house.

7. Always follow guidelines from an appliance or tool’s manufacturer.


1. Don’t run your car while it’s in your garage, even if you open the garage door.

2. Have your car regularly inspected as required by your state. Additionally, keep up with any necessary maintenance and repairs.

3. Keep up with regular boat maintenance.

4. Never swim under a boat’s swim platform or deck area near the engine.

Ads by Money. We may be compensated if you click this ad.AdAds by Money disclaimer
Keep your home safer round the clock with ADT
ADT offers top home security that could potentially help save you money on insurance* and energy costs. Get a quote now and protect what matters most.
Get Started
*Homeowner's Insurance Savings: Some insurance companies offer discounts on homeowner's insurance. Please consult your insurance company.

Causes of carbon monoxide in a house FAQs

What is the most common cause of carbon monoxide in a home?

Some of the most common causes of carbon monoxide in a home include fuel-burning appliances, heaters and cars in attached garages.

How long does it take to get carbon monoxide poisoning?

Once exposed to the fumes, the time it takes to get carbon monoxide poisoning depends on how much is ingested. According to the Cleveland Clinic, poisoning can take less than five minutes with a high concentration of carbon monoxide and up to one to two hours with a low concentration.

What causes carbon monoxide poisoning?

Carbon monoxide poisoning happens when you breathe in carbon monoxide, which is a colorless, odorless and tasteless gas. When inhaled, carbon monoxide binds to hemoglobin in your blood. As a result, your body’s organs do not receive oxygen properly. In high concentrations, poisoning can happen in a matter of minutes after inhaling carbon monoxide and can lead to death.

Summary of Money’s guide to the causes of carbon monoxide in a house

Carbon monoxide is a very dangerous gas that can build up in your home. Certain machines like gas appliances, grills, space heaters, heating systems, tools, generators, fireplaces and more can produce carbon monoxide if they malfunction or don’t have proper ventilation.

Taking precautions, such as properly maintaining and using fuel-burning machines, can prevent this deadly gas from building up in your home and poisoning you. Most importantly, always ensure you have working CO detectors on each floor of your home.