Carbon Monoxide Detectors: Ultimate Guide

Carbon monoxide (CO) is one of the most hazardous gases found in the home. Nicknamed the “silent killer,” CO gas is colorless, odorless, tasteless and non-irritating, yet it can lead to unconsciousness, brain damage or death. As a result, more than 400 people die of accidental carbon monoxide poisoning each year, a higher fatality rate compared to other types of poisoning.

When the weather gets colder, you close up your home for the winter and trust in heating appliances to remain warm. This is when the danger of carbon monoxide poisoning is highest. The good news is you can protect your family from carbon monoxide in several ways. One of the most successful methods is to put in CO detectors throughout your home. Try this guide to better 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. Because of this, this gas is generated when a fuel source burns, including natural gas, propane, oil, charcoal, gasoline, woo, and more. Frequent causes of carbon monoxide in a house may be:

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

Do smoke detectors recognize carbon monoxide?

No, smoke detectors do not detect carbon monoxide. Instead, they sound an alarm when they sense a certain amount of smoke caused by a fire. Having functional smoke detectors lowers the risk of dying in a house fire by about 55 percent.

Smoke detectors are offered in two primary forms—ionization detectors and photoelectric detectors. Ionization detection works best with fast-growing fires that emit large flames, while photoelectric models are more suited for smoldering, smoky fires. Some newer smoke detectors incorporate both forms of alarms in a single unit to increase the chance of responding to a fire, despite how it burns.

Clearly, smoke detectors and CO alarms are similarly essential home safety devices. If you check the ceiling and notice an alarm of some kind, you may not recognize whether it’s a smoke detector or a carbon monoxide alarm. The visual difference depends on the brand and model you want. Here are some factors to remember:

  • Quality devices are clearly labeled. If not, try to find a brand and model number on the back of the detector and look it up online. You will also find a manufacture date. If the device is older than 10 years, replace it right away.
  • Plug-in devices that use power with an outlet are almost always carbon monoxide detectors94. The device should be labeled as such.
  • Some alarms are two-in-one, sensing both smoke and carbon monoxide with an indicator light for each. That being said, it can be difficult to tell if there's no label on the front, so checking the manufacturing details on the back is smart.

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

The number of CO alarms you need is determined by your home’s size, how many floors it has and the number of bedrooms. Use these guidelines to ensure thorough coverage:

  • Add carbon monoxide detectors nearby bedrooms: CO gas leaks are most likely at night when furnaces are running more often to keep your home warm. For that reason, all bedrooms should have a carbon monoxide sensor installed about 15 feet of the door. If multiple bedroom doors are less than 30 feet apart, a single alarm is sufficient.
  • Install detectors on every floor:
    Dense carbon monoxide buildup can become trapped on a single floor of your home, so try to have at least one CO detector on each floor.
  • Have detectors within 10 feet of an attached garage door: Many people unsafely leave their cars on in the garage, leading to dangerous carbon monoxide gas, even while the large garage door is fully open. A CO sensor just inside the door—and in the room up above the garage—alerts you of increased carbon monoxide levels within your home.
  • Have detectors at the correct height: Carbon monoxide weighs about the same as air, but it’s often carried upward in the hot air produced by combustion appliances. Putting in detectors close to the ceiling is a good way to catch this rising air. Models that include digital readouts are best placed at eye level to keep them easy to read.
  • Install detectors around 15 feet from combustion appliances: A few fuel-burning machines produce a small, harmless amount of carbon monoxide when they start. This dissipates quickly, but when a CO detector is positioned too close, it may give off false alarms.
  • Have detectors away from excess heat and humidity: Carbon monoxide detectors have specific tolerances for heat and humidity. To minimize false alarms, avoid installing them in bathrooms, in harsh sunlight, next to air vents, or close to heat-generating appliances.

How do I test/troubleshoot a carbon monoxide alarm?

Depending on the model, the manufacturer will sometimes recommend monthly testing and resetting to ensure proper functionality. Also, replace the batteries in battery-powered units after 6 months. For hardwired units, replace the backup battery every year or when the alarm starts chirping, whichever comes first. Then, replace the CO detector outright after 10 years or according to the manufacturer’s instructions.

How to test your carbon monoxide alarm

You only need a minute to test your CO sensor. Review the instruction manual for directions specific to your unit, with the knowledge that testing uses this general procedure:

  • Press and hold the Test button. It might take 5 to 20 seconds for the alarm to begin.
  • Loud beeping means the detector is working correctly.
  • Release the Test button and wait for two short beeps, a flash or both. If the device continues beeping when you let go of the button, press and hold it again for five seconds to silence it.

Swap out the batteries if the unit isn't performing as expected after the test. If replacement batteries don’t change anything, replace the detector entirely.

How to reset your carbon monoxide alarm

You only need to reset your unit once the alarm goes off, after testing the device or after replacing the batteries. A few models automatically reset themselves within 10 minutes of these events, while other alarms need a manual reset. The instruction manual should note which function is applicable.

Follow these steps to reset your CO detector manually:

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

If you don’t notice a beep or observe a flash, attempt the reset again or replace the batteries. If it’s still not working, troubleshoot your carbon monoxide alarm with support from the manufacturer, or replace the detector.

What do I do if a carbon monoxide alarm starts?

Listen to these steps to protect your home and family:

  • Do not dismiss the alarm. You might not be able to identify dangerous levels of carbon monoxide until it’s too late, so anticipate the alarm is functioning properly when it goes off.
  • Evacuate all people and pets immediately. If you can, open windows and doors on your way out to help thin out the concentration of CO gas.
  • Call 911 or a local fire department and inform them that the carbon monoxide alarm has started.
  • It's wrong to think it’s safe to reenter your home when the alarm is no longer beeping. Opening windows and doors may help air it out, but the root cause may still be generating carbon monoxide.
  • When emergency responders come, they will enter your home, measure carbon monoxide levels, check for the source of the CO leak and figure out if it’s safe to go back inside. Depending on the cause, you might need to arrange repair services to prevent the problem from recurring.

Find Support from Service Experts Heating & Air Conditioning

With the appropriate precautions, there’s no need to fear carbon monoxide inhalation in your home. Along with installing CO alarms, it’s worthwhile to maintain your fuel-burning appliances, namely as winter starts.

The team at Service Experts Heating & Air Conditioning is qualified to inspect, clean, diagnose and repair problems with furnaces, boilers, water heaters and other combustion appliances. We recognize which signs suggest a potential carbon monoxide leak— such as increased soot, rusted flue pipes and a yellow, flickering burner flame—along with the necessary repairs to resolve them.

Do you still have questions or concerns about CO exposure? Is it time to schedule annual heating services? Contact Service Experts Heating & Air Conditioning for more information.

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