Carbon Monoxide Detectors: Ultimate Guide

Carbon monoxide (CO) is one of the most hazardous gases found in the home. Dubbed 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 influence each year, a larger fatality rate than any other kind of poisoning.

When the weather cools down, you seal your home for the winter and count on heating appliances to keep warm. This is when the threat 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 successful methods is to add CO detectors throughout your home. Try this guide to help you understand where carbon monoxide comes from and how to make the most of your CO alarms.

What produces carbon monoxide in a house?

Carbon monoxide is a byproduct of something burned. Therefore, this gas can appear when a fuel source burns, such as natural gas, propane, oil, charcoal, gasoline, woo, and more. Common causes of carbon monoxide in a house include:

Overloaded clothes dryer vent
Broken down 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 sitting in the garage
Portable generator, grill, power tool or lawn equipment running in the garage

Do smoke detectors recognize carbon monoxide?

No, smoke detectors do not detect carbon monoxide. In fact, they start an alarm when they recognize a certain concentration of smoke generated by a fire. Possessing reliable smoke detectors decreases the risk of dying in a house fire by around 55 percent.

Smoke detectors are available in two basic forms—ionization detectors and photoelectric detectors. Ionization detection works best with fast-moving fires that generate large flames, while photoelectric detectors are more effective with smoldering, smoky fires. The newest smoke detectors incorporate both kinds of alarms in one unit to boost the chance of sensing a fire, no matter how it burns.

Unmistakably, smoke detectors and CO alarms are similarly important home safety devices. If you inspect the ceiling and see an alarm of some kind, you might not recognize whether it’s a smoke detector or a carbon monoxide alarm. The visual difference is based on the brand and model you prefer. Here are several factors to consider:

Most devices are visibly labeled. If not, check for a brand and model number on the back of the detector and find it online. You can 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 through an outlet are generally carbon monoxide detectors94. The device is supposed to be labeled saying as much.
Some alarms will be two-in-one, offering protection against both smoke and carbon monoxide with an indicator light for each. Nevertheless, it can be hard to tell without a label on the front, so reviewing the manufacturing details on the back is smart.

How many carbon monoxide detectors should I install in my home?

The number of CO alarms you should have is dependent on your home’s size, the number of stories and the number of bedrooms. Consider these guidelines to provide thorough coverage:

Install carbon monoxide detectors around sleeping areas: CO gas leaks are most common at night when furnaces are running constantly to keep your home heated. As a result, every bedroom should have a carbon monoxide detector installed around 15 feet of the door. If a couple of bedroom doors are less than 30 feet apart, a single alarm is sufficient.
Add detectors on every floor:
Dangerous carbon monoxide gas can become trapped on a single floor of your home, so do your best to have at least one CO detector on all floors.
Install detectors within 10 feet of your internal garage door: Many people unsafely leave their cars idling in the garage, resulting in dangerous carbon monoxide buildup, even while the large garage door is fully open. A CO sensor immediately inside the door—and in the room over the garage—alerts you of elevated carbon monoxide levels inside your home.
Have detectors at the proper height: Carbon monoxide weighs about the same as air, but it’s often carried upward in the hot air produced by combustion appliances. Installing detectors near the ceiling is best to catch this rising air. Models that include digital readouts are best placed at eye level to make them easier to read.
Install detectors about 15 feet from combustion appliances: Some fuel-burning machines give off a small, harmless amount of carbon monoxide when they start. This breaks up quickly, but if a CO detector is positioned too close, it may trigger false alarms.
Have detectors away from extreme 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 specific unit, the manufacturer may recommend testing once a month and resetting to ensure proper functionality. Also, swap out the batteries in battery-powered units twice a year. For hardwired units, replace the backup battery annually or when the alarm begins chirping, whichever comes first. Then, replace the CO detector entirely after 10 years or in line with the manufacturer’s recommendations.

How to test your carbon monoxide alarm

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

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 working correctly.
Let go of the Test button and wait for two quick beeps, a flash or both. If the device keeps beeping when you release the button, press and hold it again for five seconds to silence it.

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

How to reset your carbon monoxide alarm

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

Use 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 get a beep or see a flash, start the reset again or replace the batteries. If it’s still not working, troubleshoot your carbon monoxide alarm with support from the manufacturer, or get rid of the faulty detector.

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

Use these steps to take care of your home and family:

Do not ignore the alarm. You may not be able to detect hazardous levels of carbon monoxide until it’s too late, so expect the alarm is functioning correctly when it is triggered.
Evacuate all people and pets immediately. If you can, open windows and doors on your way out to attempt to weaken the concentration of CO gas.
Call 911 or your local fire department and inform them that the carbon monoxide alarm has gone off.
Don't assume it’s safe to reenter your home when the alarm stops beeping. Opening windows and doors might help air it out, but the root cause may still be creating carbon monoxide.
When emergency responders come, they will enter your home, assess carbon monoxide levels, try to find the source of the CO leak and determine if it’s safe to return. Depending on the cause, you may need to arrange repair services to keep the problem from recurring.

Find Support from Norrell Service Experts

With the appropriate precautions, there’s no need to be afraid of carbon monoxide exposure in your home. In addition to installing CO alarms, it’s worthwhile to maintain your fuel-burning appliances, especially as winter arrives.

The team at Norrell Service Experts is qualified to inspect, clean, diagnose and repair issues with furnaces, boilers, water heaters and other combustion appliances. We know what 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 resolve them.

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