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, yet it can result in unconsciousness, brain damage or death. Because of this, more than 400 people die as a result of carbon monoxide exposure each year, a larger fatality rate than any other kind of poisoning.

When the weather gets colder, you insulate your home for the winter and count on heating appliances to keep warm. This is when the risk of carbon monoxide poisoning is highest. The good news is you can protect your family from carbon monoxide in a variety of ways. One of the most effective methods is to put in CO detectors in your home. Check out this guide to help you understand where carbon monoxide can appear from and how to reap the benefits of your CO alarms.

What generates carbon monoxide in a house?

Carbon monoxide is a byproduct of incomplete combustion. Therefore, this gas can appear anytime a fuel source burns, including natural gas, propane, oil, charcoal, gasoline, woo, and more. Prevalent causes of carbon monoxide in a house include:

  • Overloaded clothes dryer vent
  • Faulty water heater
  • Furnace or boiler with a cracked heat exchanger
  • Closed fireplace flue during an active fire
  • 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 begin an alarm when they sense a certain concentration of smoke caused by a fire. Having reliable smoke detectors lowers the risk of dying in a house fire by nearly 55 percent.

Smoke detectors are available in two primary forms—ionization detectors and photoelectric detectors. Ionization detection is ideal with fast-moving fires that emit large flames, while photoelectric detection is more applicable for smoldering, smoky fires. A few smoke detectors include both forms of alarms in a single unit to boost the chance of responding to a fire, no matter how it burns.

Clearly, smoke detectors and CO alarms are similarly important home safety devices. If you check 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 contrast is determined by the brand and model you have. Here are several factors to remember:

  • Some devices are visibly labeled. If not, try to find 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 10 years old, replace it at the earliest opportunity.
  • Plug-in devices that extract power through an outlet are generally carbon monoxide detectors94. The device is supposed to be labeled saying as much.
  • Some alarms are really two-in-one, sensing both smoke and carbon monoxide with a separate indicator light for each. That being said, it can be hard to tell without a label on the front, so checking the manufacturing details on the back is worthwhile.

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

The number of CO alarms you need depends on your home’s size, how many floors it has and bedroom arrangement. Use these guidelines to guarantee thorough coverage:

  • Install carbon monoxide detectors nearby sleeping areas: CO gas leaks are most common at night when furnaces have to run constantly to keep your home comfortable. Therefore, 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, just one detector is sufficient.
  • Put in detectors on every floor:
    Dense 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 all floors.
  • Have detectors within 10 feet of the internal garage door: Many people unsafely leave their cars idling in the garage, leading to dangerous carbon monoxide gas, even while the large garage door is completely open. A CO detector just inside the door—and in the room over the garage—alerts you of increased carbon monoxide levels within your home.
  • Put in detectors at the proper height: Carbon monoxide is a similar density as air, but it’s often carried along with the hot air created by combustion appliances. Having detectors close to the ceiling is best to catch this rising air. Models that come with digital readouts are best placed at eye level to make them easier to read.
  • Put in detectors around 15 feet from combustion appliances: Certain fuel-burning machines give off a tiny, harmless amount of carbon monoxide as they first start running. This disperses quickly, but in situations where a CO detector is installed right next to it, it may give off false alarms.
  • Install detectors away from excess heat and humidity: Carbon monoxide detectors have specific tolerances for heat and humidity. To limit false alarms, don't install them in bathrooms, in strong 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 will sometimes encourage monthly testing and resetting to sustain proper functionality. Also, change out the batteries in battery-powered units after 6 months. For hardwired units, replace the backup battery once a year or when the alarm begins chirping, whichever starts first. Then, replace the CO detector entirely every 10 years or in line with the manufacturer’s guidelines.

How to test your carbon monoxide alarm

You only need a minute to test your CO alarm. Check the instruction manual for directions unique to your unit, understanding that testing uses this general routine:

  • Press and hold the Test button. It may take 5 to 20 seconds for the alarm to go off.
  • Loud beeping signifies the detector is working correctly.
  • Let go of the Test button and wait for two short beeps, a flash or both. If the device keeps beeping when you let go of the button, press and hold it again for five seconds to quiet it.

Swap out the batteries if the unit won't work as expected during 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 running a test or after swapping the batteries. A few models automatically reset themselves within 10 minutes of these events, while other models need a manual reset. The instruction manual can note which function is applicable.

Carry out 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 notice a beep or observe a flash, start the reset again or replace the batteries. If that doesn't help either, troubleshoot your carbon monoxide alarm with assistance from the manufacturer, or install a new detector.

What can I do if a carbon monoxide alarm starts?

Listen to these steps to protect your home and family:

  • Do not disregard the alarm. You won't always be able to detect hazardous levels of carbon monoxide until it’s too late, so anticipate the alarm is functioning properly when it is triggered.
  • Evacuate all people and pets as quickly as possible. If you can, open windows and doors on your way out to attempt to thin out the concentration of CO gas.
  • Call 911 or the local fire department and inform them that the carbon monoxide alarm has started.
  • Don't assume it’s safe to reenter your home when the alarm is no longer beeping. Opening windows and doors can help air it out, but the root cause could still be producing carbon monoxide.
  • When emergency responders show up, they will go into your home, measure carbon monoxide levels, check for the source of the CO leak and determine if it’s safe to come back inside. Depending on the cause, you will sometimes need to arrange repair services to prevent the problem from recurring.

Seek Support from Service Experts Heating & Air Conditioning

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

The team at Service Experts Heating & Air Conditioning is happy to inspect, clean, diagnose and repair malfunctions with furnaces, boilers, water heaters and other combustion appliances. We know what signs indicate a possible carbon monoxide leak— like excess soot, rusted flue pipes and a yellow, flickering burner flame—along with the necessary repairs to avoid 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.