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 cause unconsciousness, brain damage or death. As a result, more than 400 people die of accidental carbon monoxide influence each year, a higher 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. These situations are when the risk of carbon monoxide poisoning is highest. The good news is you can protect your family from carbon monoxide in different ways. One of the most effective 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 produces carbon monoxide in a house? 

Carbon monoxide is a byproduct of incomplete combustion. Because of this, this gas can appear anytime a fuel source is burned, including natural gas, propane, oil, charcoal, gasoline, woo, and more. Frequent 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 running in the garage 

Do smoke detectors detect carbon monoxide? 

No, smoke detectors do not detect carbon monoxide. Alternatively, they sound an alarm when they sense a certain concentration of smoke produced by a fire. Having functional 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 fast-growing fires that produce large flames, while photoelectric detection is more effective with smoldering, smoky fires. Some newer smoke detectors incorporate both types of alarms in a single unit to increase the chance of sensing a fire, no matter how it burns. 

Clearly, smoke detectors and CO alarms are both important home safety devices. If you look up at the ceiling and see an alarm of some kind, you won’t always know 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 keep in mind: 

• Some devices are clearly labeled. If not, check for a brand and model number on the back of the detector and find it 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 through an outlet are generally carbon monoxide is supposed to be labeled as such. 
• Some alarms are two-in-one, detecting both smoke and carbon monoxide with an 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 your best bet. 

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

The number of CO alarms you should have depends on your home’s size, the number of stories and bedroom arrangement. Follow these guidelines to provide thorough coverage: 

• Install carbon monoxide detectors near sleeping areas: CO gas leaks are most common at night when furnaces have to run frequently to keep your home comfortable. Therefore, all bedrooms should have a carbon monoxide detector installed within 15 feet of the door. If two bedroom doors are less than 30 feet apart, a single alarm is adequate. 
• Put in detectors on every floor: 
  Dangerous carbon monoxide buildup can become trapped on a single floor of your home, so try to have at least one CO detector on all floors. 
• Install detectors within 10 feet of the internal garage door: A surprising number of people unsafely leave their cars idling in the garage, producing dangerous carbon monoxide buildup, even when the large garage door is wide open. A CO detector immediately inside the door—and in the room above the garage—alerts you of elevated carbon monoxide levels inside your home. 
• Install detectors at the proper height: Carbon monoxide weighs about the same as air, but it’s frequently carried along with the hot air produced by combustion appliances. Having detectors near the ceiling is best to catch this rising air. Models with digital readouts are best located at eye level to make them easier to read. 
• Put in detectors at least 15 feet from combustion appliances: Some fuel-burning machines give off a tiny, harmless amount of carbon monoxide at startup. This dissipates quickly, but when a CO detector is positioned too close, it could give off false alarms. 

• Install detectors away from high heat and humidity: Carbon monoxide detectors have specific tolerances for heat and humidity. To reduce 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 encourage monthly testing and resetting to maintain proper functionality. Also, replace the batteries in battery-powered units every six months. For hardwired units, replace the backup battery every 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 instructions. 

How to test your carbon monoxide alarm 

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

• Press and hold the Test button. It may take 5 to 20 seconds for the alarm to start. 
• Loud beeping indicates the detector is operating 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. 

Change the batteries if the unit isn’t performing 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 once the alarm goes off, after testing the device or after changing 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, start the reset again or replace the batteries. If it’s still not working, troubleshoot your carbon monoxide alarm with assistance from the manufacturer, or replace the detector. 

What do I do if a carbon monoxide alarm goes off? 

Use these steps to protect your home and family: 

• Do not dismiss the alarm. You won’t always be able to detect unsafe levels of carbon monoxide until it’s too late, so assume the alarm is functioning correctly when it goes off. 
• Evacuate all people and pets immediately. If you can, open windows and doors on your way out to help dilute the concentration of CO gas. 
• Call 911 or your local fire department and report that the carbon monoxide alarm has triggered. 

• 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 enter your home, assess 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 arrange repair services to prevent the problem from returning. 

Get Support from Stevenson Service Experts 

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

The team at Stevenson Service Experts is qualified to inspect, clean, diagnose and repair problems with furnaces, boilers, water heaters and other combustion appliances. We know what signs could mean a possible carbon monoxide leak— including excessive 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 Stevenson Service Experts for more information.