Carbon Monoxide Detectors: Ultimate Guide

Carbon monoxide (CO) is a common risk found in the home. Nicknamed the “silent killer,” CO gas is colorless, odorless, tasteless and non-irritating, yet it can cause unconsciousness, brain damage or death. Consequently, more than 400 people die as a result of carbon monoxide exposure each year, a higher fatality rate than any other kind of poisoning.

When the weather cools off, you insulate your home for the winter and rely on heating appliances to stay warm. This is when the threat of carbon monoxide inhalation is highest. Fortunately you can safeguard your family from carbon monoxide in a variety of ways. One of the most efficient 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 reap the benefits of your CO detectors.

What causes carbon monoxide in a house?

Carbon monoxide is a byproduct of something burned. As a result, this gas is produced when a fuel source is burned, like natural gas, propane, oil, charcoal, gasoline, woo, and more. Common causes of carbon monoxide in a house include:

  • Overloaded clothes dryer vent
  • Malfunctioning water heater
  • Furnace or boiler with a broken heat exchanger
  • Closed fireplace flue during an active fire
  • Improperly vented gas or wood stove
  • Vehicle sitting in the garage
  • Portable generator, grill, power tool or lawn equipment being used in the garage

Do smoke detectors detect carbon monoxide?

No, smoke detectors do not detect carbon monoxide. In fact, they start an alarm when they detect a certain concentration of smoke generated by a fire. Having reliable smoke detectors reduces 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 functions well with fast-moving fires that produce large flames, while photoelectric detectors are more applicable for smoldering, smoky fires. A few smoke detectors incorporate both types of alarms in a single unit to maximize the chance of sensing a fire, regardless of how it burns.

Clearly, smoke detectors and CO alarms are equally important home safety devices. If you check 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 prefer. Here are a few factors to consider:

  • Quality devices are clearly labeled. If not, look for 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 more than a decade old, replace it at the earliest opportunity.
  • Plug-in devices that draw power from an outlet are almost always carbon monoxide sensors94. The device will be labeled as such.
  • Some alarms are two-in-one, detecting both smoke and carbon monoxide with an indicator light for each. That being said, it can be tough to tell with no label on the front, so checking the manufacturing details on the back is your best bet.

How many carbon monoxide detectors will I want in my home?

The number of CO alarms you require is determined by your home’s size, number of floors and the number of bedrooms. Follow these guidelines to ensure total coverage:

  • Place carbon monoxide detectors nearby sleeping areas: CO gas leaks are most prevalent at night when furnaces are running frequently to keep your home comfortable. As a result, each bedroom should have a carbon monoxide sensor installed about 15 feet of the door. If a couple of bedroom doors are less than 30 feet apart, one detector is sufficient.
  • Install detectors on every floor:
    Dangerous carbon monoxide gas can become trapped on a single floor of your home, so make sure you have at least one CO detector on all floors.
  • Install detectors within 10 feet of the internal garage door: A lot of people end up leaving their cars running in the garage, producing dangerous carbon monoxide gas, even when the large garage door is wide open. A CO alarm immediately inside the door—and in the room up above the garage—alerts you of heightened carbon monoxide levels entering your home.
  • Have detectors at the proper height: Carbon monoxide weighs about the same as air, but it’s commonly carried along with the hot air produced by combustion appliances. Putting in detectors near the ceiling is best to catch this rising air. Models with digital readouts are best located at eye level to keep them easy to read.
  • Add detectors around 15 feet from combustion appliances: Some fuel-burning machines emit a small, harmless amount of carbon monoxide at startup. This dissipates quickly, but when a CO detector is installed right next to it, it might trigger false alarms.
  • Install detectors away from high heat and humidity: Carbon monoxide detectors have specific tolerances for heat and humidity. To limit false alarms, don't install them in bathrooms, in harsh 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 might encourage testing once a month and resetting to maintain proper functionality. Also, change out the batteries in battery-powered units twice a year. For hardwired units, replace the backup battery annually or when the alarm is chirping, whichever happens first. Then, replace the CO detector entirely after 10 years or as outlined by the manufacturer’s guidelines.

How to test your carbon monoxide alarm

All it takes is a minute to test your CO sensor. Review the instruction manual for directions individual to your unit, understanding that testing practices this general routine:

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

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

How to reset your carbon monoxide alarm

You only have to reset your unit after the alarm goes off, after running a test or after swapping the batteries. Some models automatically reset themselves in under 10 minutes of these events, while other alarms need a manual reset. The instruction manual can note which function you should use.

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 get a beep or observe a flash, start the reset again or replace the batteries. If it’s still not working, troubleshoot your carbon monoxide alarm with help from the manufacturer, or install a new detector.

What do I do if a carbon monoxide alarm starts?

Listen to these steps to safeguard your home and family:

  • Do not disregard the alarm. You may not be able to notice hazardous levels of carbon monoxide until it’s too late, so assume the alarm is working correctly when it starts.
  • Evacuate all people and pets as soon as possible. If you're able to, open windows and doors on your way out to help dilute the concentration of CO gas.
  • Call 911 or a local fire department and explain that the carbon monoxide alarm has gone off.
  • Do not assume it’s safe to reenter your home when the alarm stops beeping. Opening windows and doors can help air it out, but the root cause might still be producing carbon monoxide.
  • When emergency responders come, they will search your home, measure carbon monoxide levels, try to find 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 stop the problem from returning.

Seek Support from Service Experts Heating & Air Conditioning

With the proper precautions, there’s no need to worry about carbon monoxide inhalation in your home. In addition to installing CO alarms, it’s important to maintain your fuel-burning appliances, particularly as winter gets underway.

The team at Service Experts Heating & Air Conditioning is qualified to inspect, clean, diagnose and repair issues with furnaces, boilers, water heaters and other combustion appliances. We recognize which signs could mean a potential carbon monoxide leak— like excess soot, rusted flue pipes and a yellow, flickering burner flame—along with the necessary repairs to prevent 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.