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 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 poisoning is highest. The good news is you can defend your family from carbon monoxide in several ways. One of the most successful methods is to install CO detectors in your home. Use 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 incomplete combustion. Therefore, this gas is produced 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: 

• 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 start an alarm when they sense a certain level of smoke caused 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 forms—ionization detectors and photoelectric detectors. Ionization detection works best with fast-moving fires that produce large flames, while photoelectric models are more effective with smoldering, smoky fires. A few smoke detectors come with 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 equally important home safety devices. If you inspect the ceiling and see an alarm of some kind, you may not recognize whether it’s a smoke detector or a carbon monoxide alarm. The visual difference is determined by the brand and model you prefer. Here are a few factors to consider: 

• 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 10 years old, replace it as soon as possible. 
• Plug-in devices that draw power through an outlet are typically carbon monoxide is supposed to be labeled as such. 
• Some alarms will be 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 will I want in my home? 

The number of CO alarms you need is dependent on your home’s size, the number of stories and bedroom arrangement. Follow these guidelines to ensure thorough coverage: 

• Install carbon monoxide detectors near sleeping areas: CO gas leaks are most prevalent at night when furnaces must run more often to keep your home warm. Therefore, all bedrooms should have a carbon monoxide alarm installed within 15 feet of the door. If two bedroom doors are less than 30 feet apart, just one detector is sufficient. 
• Install detectors on every floor: 
  Dangerous carbon monoxide buildup can become trapped on a single floor of your home, so do your best to have at least one CO detector on every level. 
• Have 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. 
• Have detectors at the correct height: Carbon monoxide weighs about the same as air, but it’s often pushed up by 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 placed at eye level to make them easier 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 when a CO detector is positioned too close, it could give off false alarms. 

• Have detectors away from high heat and humidity: Carbon monoxide detectors have specific tolerances for heat and humidity. To limit 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 alarm? 

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

How to test your carbon monoxide alarm 

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

• Press and hold the Test button. It might take 5 to 20 seconds for the alarm to go off. 
• Loud beeping indicates the detector is working 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 during the test. If replacement batteries don’t make a difference, replace the detector immediately. 

How to reset your carbon monoxide alarm 

You only have to reset your unit when 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 help from the manufacturer, or get rid of the faulty detector. 

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

Use 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 expect the alarm is working correctly when it is triggered. 
• 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, evaluate 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 may need to arrange repair services to prevent the problem from recurring. 

Seek Support from Robinson Service Experts 

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

The team at Robinson 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 possible carbon monoxide leak— like excessive 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 Robinson Service Experts for more information.