Carbon Monoxide Detectors: Ultimate Guide

Carbon monoxide (CO) is a potentially hazardous gas found in the home. Known as the “silent killer,” CO gas is colorless, odorless, tasteless and non-irritating, but it can result in unconsciousness, brain damage or death. As a result, more than 400 people die of accidental carbon monoxide poisoning each year, a steeper fatality rate than any other kind of poisoning.

When the weather cools down, you insulate your home for the winter and trust in heating appliances to remain warm. These situations are when the risk of carbon monoxide exposure is highest. Fortunately you can defend your family from a gas leak in different ways. One of the most effective methods is to add CO detectors throughout your home. Use this guide to help you understand where carbon monoxide can appear from and how to take full advantage of your CO alarms.

What causes carbon monoxide in a house?

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

  • Clogged clothes dryer vent
  • Broken down water heater
  • Furnace or boiler with a cracked heat exchanger
  • Closed fireplace flue with a lit fire
  • Improperly 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 detect carbon monoxide?

No, smoke detectors do not detect carbon monoxide. In fact, they sound an alarm when they sense a certain concentration of smoke produced by a fire. Installing functional smoke detectors reduces the risk of dying in a house fire by about 55 percent.

Smoke detectors come in two main forms—ionization detectors and photoelectric detectors. Ionization detection functions well with fast-growing fires that emit large flames, while photoelectric detectors are more suited for smoldering, smoky fires. A few smoke detectors come with both types of alarms in a solitary unit to increase the chance of sensing a fire, regardless of how it burns.

Clearly, smoke detectors and CO alarms are both beneficial home safety devices. If you inspect the ceiling and notice an alarm of some kind, you won't always recognize whether it’s a smoke detector or a carbon monoxide alarm. The visual contrast is determined by the brand and model you want. Here are some factors to consider:

  • Quality devices are visibly labeled. If not, look 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 at the earliest opportunity.
  • Plug-in devices that use power from an outlet are typically carbon monoxide alarms94. The device is supposed to be labeled so.
  • Some alarms are really two-in-one, offering protection against both smoke and carbon monoxide with a different indicator light for each. That being said, it can be difficult to tell without a label on the front, so reviewing the manufacturing details on the back is smart.

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

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

  • Add carbon monoxide detectors around sleeping areas: CO gas poisoning is most prevalent at night when furnaces have to run more often to keep your home comfortable. As a result, every bedroom should have a carbon monoxide alarm installed around 15 feet of the door. If multiple bedroom doors are less than 30 feet apart, a single alarm is adequate.
  • Add detectors on all floors:
    Dense carbon monoxide gas can become trapped on a single floor of your home, so try to have at least one CO detector on every level.
  • Have detectors within 10 feet of an attached garage door: A lot of people accidentally leave their cars on in the garage, resulting in dangerous carbon monoxide gas, even when the large garage door is completely open. A CO detector right 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 appropriate height: Carbon monoxide is a similar density as air, but it’s commonly carried along with the hot air released by combustion appliances. Having detectors close to the ceiling is a good way to catch this rising air. Models that include digital readouts are best located at eye level to make sure they're easy to read.
  • Add detectors around 15 feet from combustion appliances: Certain fuel-burning machines produce a tiny, non-toxic amount of carbon monoxide as they first start running. This breaks up quickly, but when a CO detector is nearby, it might trigger false alarms.
  • Install detectors away from high heat and humidity: Carbon monoxide detectors have certain 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 alarm?

Depending on the design, the manufacturer will sometimes suggest 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 annually or when the alarm starts chirping, whichever happens first. Then, replace the CO detector outright after 10 years or in line with the manufacturer’s instructions.

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 procedure:

  • Press and hold the Test button. It will sometimes need 5 to 20 seconds for the alarm to go off.
  • Loud beeping signifies the detector is operating correctly.
  • Release the Test button and wait for two short beeps, a flash or both. If the device goes on beeping when you let go of the button, press and hold it again for five seconds to quiet it.

Replace 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 have to reset your unit after the alarm goes off, after a test or after replacing the batteries. Certain models automatically reset themselves in under 10 minutes of these events, while other alarms require a manual reset. The instruction manual should 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 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 help from the manufacturer, or install a new detector.

What should I do if a carbon monoxide alarm starts?

Listen to these steps to protect your home and family:

  • Do not dismiss the alarm. You might not be able to identify hazardous levels of carbon monoxide until it’s too late, so expect the alarm is functioning properly when it starts.
  • Evacuate all people and pets as quickly 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 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 source might still be generating carbon monoxide.
  • When emergency responders arrive, they will go into your home, assess carbon monoxide levels, look for the source of the CO leak and establish if it’s safe to go back inside. Depending on the cause, you may need to arrange repair services to prevent the problem from reappearing.

Get Support from Service Experts Heating & Air Conditioning

With the proper precautions, there’s no need to worry about carbon monoxide poisoning in your home. In addition to installing CO alarms, it’s worthwhile to maintain your fuel-burning appliances, namely as winter arrives.

The team at Service Experts Heating & Air Conditioning is qualified to inspect, clean, diagnose and repair malfunctions with furnaces, boilers, water heaters and other combustion appliances. We know what signs indicate a likely carbon monoxide leak— such as 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.