Carbon Monoxide Detectors: Ultimate Guide

Carbon monoxide (CO) is one of the most hazardous gases found in the home. Known as the “silent killer,” CO gas is colorless, odorless, tasteless and non-irritating, but it can cause unconsciousness, brain damage or death. Because of this, more than 400 people die of accidental carbon monoxide exposure each year, a steeper fatality rate than any other type of poisoning. 

As the weather cools off, you close up your home for the winter and trust in heating appliances to stay warm. This is when the risk of carbon monoxide inhalation is highest. The good news is you can protect your family from carbon monoxide in several ways. One of the most efficient methods is to install CO detectors in your home. Use this guide to help you understand where carbon monoxide can appear from and how to make the most of your CO alarms. 

What generates carbon monoxide in a house? 

Carbon monoxide is a byproduct of incomplete combustion. As a result, this gas is generated whenever a fuel source is burned, including natural gas, propane, oil, charcoal, gasoline, woo, and more. Prevalent causes of carbon monoxide in a house include: 

  • Clogged clothes dryer vent 
  • Malfunctioning water heater 
  • Furnace or boiler with a cracked heat exchanger
  • Closed fireplace flue while a fire is lit 
  • Improperly vented gas or wood stove 
  • Vehicle idling in the garage 
  • Portable generator, grill, power tool or lawn equipment operating in the garage 

Do smoke detectors detect carbon monoxide? 

No, smoke detectors do not detect carbon monoxide. Instead, they sound an alarm when they sense a certain level of smoke generated by a fire. Having dependable smoke detectors reduces the risk of dying in a house fire by nearly 55 percent

Smoke detectors come in two primary modes—ionization detectors and photoelectric detectors. Ionization detection works best with quick-moving fires that produce large flames, while photoelectric models are more effective with smoldering, smoky fires. Some newer smoke detectors include both types of alarms in a single unit to increase the chance of sensing a fire, no matter how it burns. 

Unmistakably, smoke detectors and CO alarms are equally important home safety devices. If you look up at the ceiling and notice an alarm of some kind, you may not realize whether it’s a smoke detector or a carbon monoxide alarm. The visual difference depends on the brand and model you have. Here are several factors to keep in mind: 

  • Some devices are clearly labeled. If not, check for a brand and model number on the back of the detector and look it up online. You should also find a manufacture date. If the device is more than a decade old, replace it as soon as possible. 
  • Plug-in devices that draw power with an outlet are almost always carbon monoxide detectors be labeled as such. 
  • Some alarms are really two-in-one, detecting both smoke and carbon monoxide with a separate indicator light for each. Still, it can be hard to tell without a label on the front, so checking the manufacturing details on the back is worthwhile. 

How many carbon monoxide detectors do I need in my home? 

The number of CO alarms you need depends on your home’s size, how many floors it has and bedroom arrangement. Follow these guidelines to guarantee thorough coverage: 

  • Install carbon monoxide detectors near sleeping areas: CO gas poisoning is most common at night when furnaces are running more often to keep your home warm. Therefore, every bedroom should have a carbon monoxide alarm installed within 15 feet of the door. If two bedroom doors are less than 30 feet apart, one detector is adequate. 
  • Install detectors on all floors: 
    Dangerous carbon monoxide buildup can become trapped on a single floor of your home, so make sure you have at least one CO detector on each floor. 
  • Put in detectors within 10 feet of the internal garage door: Many people unsafely leave their cars idling in the garage, resulting in dangerous carbon monoxide buildup, even when the large garage door is wide open. A CO alarm immediately inside the door—and in the room above the garage—alerts you of elevated carbon monoxide levels entering your home. 
  • Put in detectors at the appropriate height: Carbon monoxide weighs about the same as air, but it’s commonly carried upward in the hot air created by combustion appliances. Installing detectors up against the ceiling is best to catch this rising air. Models with digital readouts are best placed at eye level to make sure they’re easy to read. 
  • Install detectors around 15 feet from combustion appliances: Some fuel-burning machines give off a tiny, harmless amount of carbon monoxide when they start. This dissipates quickly, but in situations where a CO detector is positioned too close, it could give off false alarms. 
  • Put in detectors away from high heat and humidity: Carbon monoxide detectors have specific tolerances for heat and humidity. To minimize false alarms, avoid installing them in bathrooms, in direct sunlight, near air vents, or close to heat-generating appliances. 

How do I test/troubleshoot a carbon monoxide detector? 

Depending on the model, the manufacturer may suggest monthly testing and resetting to sustain proper functionality. Also, replace the batteries in battery-powered units every six months. For hardwired units, replace the backup battery once a year or when the alarm starts chirping, whichever comes first. Then, replace the CO detector entirely every 10 years or according to the manufacturer’s guidelines. 

How to test your carbon monoxide alarm 

It only takes a minute to test your CO detector. Check the instruction manual for directions individual to your unit, knowing that testing follows this general procedure: 

  • Press and hold the Test button. It may take 5 to 20 seconds for the alarm to go off. 
  • Loud beeping means the detector is functioning correctly. 
  • Release the Test button and wait for two quick beeps, a flash or both. If the device continues beeping when you release the button, press and hold it again for five seconds to silence it. 

Swap out the batteries if the unit fails to perform as expected for the test. If replacement batteries don’t make a difference, replace the detector immediately. 

How to reset your carbon monoxide alarm 

You’re only required to reset your unit after the alarm goes off, after testing the device or after replacing the batteries. Some models automatically reset themselves within 10 minutes of these events, while others require a manual reset. The instruction manual will note which function applies. 

Follow these steps to reset your CO detector manually: 

  • Press and hold the Reset button for 5 to 10 seconds. 
  • Release the button and wait for a beep, a flash or both. 

If you don’t hear a beep or see a flash, try the reset again or replace the batteries. If it’s still not working, troubleshoot your carbon monoxide alarm with support from the manufacturer, or install a new detector. 

What do I do if a carbon monoxide alarm is triggered? 

Follow these steps to protect your home and family: 

  • Do not disregard the alarm. You may not be able to detect unsafe levels of carbon monoxide until it’s too late, so assume the alarm is working correctly when it is triggered. 
  • Evacuate all people and pets as quickly as possible. If you can, open windows and doors on your way out to try and dilute the concentration of CO gas. 
  • Call 911 or your local fire department and report that the carbon monoxide alarm has started. 
  • Do not assume it’s safe to reenter your home when the alarm stops beeping. Opening windows and doors may help air it out, but the source could still be producing carbon monoxide. 
  • When emergency responders arrive, they will go into your home, measure carbon monoxide levels, check for the source of the CO leak and determine if it’s safe to go back inside. Depending on the cause, you may need to schedule repair services to prevent the problem from recurring. 

Get Support from Chief/Bauer Service Experts 

With the proper precautions, there’s no need to fear carbon monoxide exposure in your home. Along with installing CO alarms, it’s worthwhile to maintain your fuel-burning appliances, especially as winter gets underway. 

The team at Chief/Bauer Service Experts is qualified to inspect, clean, diagnose and repair problems with furnaces, boilers, water heaters and other combustion appliances. We know what signs indicate a likely carbon monoxide leak— such as excessive soot, rusted flue pipes and a yellow, flickering burner flame—along with the necessary repairs to avoid them. 

Do you still have questions or concerns about CO exposure? Is it time to schedule annual heating services? Contact Chief/Bauer Service Experts for more information. 

Savings For You

See All Offers Here >

Free Indoor Air Quality Consultation

  • Written 100% Satisfaction Guarantee

© 2023 Service Experts, Service Experts Heating & Air Conditioning, and the Service Experts logo and design are registered trademarks of Service Experts LLC and used under license by SE Canada Inc. All Rights Reserved. *Not applicable to the Advantage Program. See your signed Advantage Program Agreement for full details and exclusions. 100% Satisfaction Guarantee is subject to certain restrictions and limitations as set forth in the applicable Terms and Conditions.