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, however it can cause unconsciousness, brain damage or death. Because of this, 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 down, you insulate your home for the winter and rely on heating appliances to remain warm. These situations are when the risk of carbon monoxide inhalation is highest. Thankfully you can defend your family from carbon monoxide in different ways. One of the most effective methods is to put in CO detectors throughout your home. Try this guide to better 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. Therefore, this gas is produced anytime a fuel source is ignited, like natural gas, propane, oil, charcoal, gasoline, woo, and more. Frequent causes of carbon monoxide in a house include:

  • Overloaded clothes dryer vent
  • Faulty water heater
  • Furnace or boiler with a damaged heat exchanger
  • Closed fireplace flue with a lit fire
  • Improperly vented gas or wood stove
  • Vehicle running 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. In fact, they begin an alarm when they detect a certain concentration of smoke produced by a fire. Having reliable smoke detectors decreases the risk of dying in a house fire by about 55 percent.

Smoke detectors are available in two main modes—ionization detectors and photoelectric detectors. Ionization detection functions well with fast-growing fires that generate large flames, while photoelectric detection is more effective with smoldering, smoky fires. The newest smoke detectors include both forms of alarms in one unit to increase the chance of responding to 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 notice an alarm of some kind, you may not know whether it’s a smoke detector or a carbon monoxide alarm. The visual discrepancy is based on the brand and model you prefer. Here are a few factors to remember:

  • Most devices are visibly labeled. If not, look for a brand and model number on the back of the detector and locate it online. You should also find a manufacture date. If the device is older than 10 years, replace it as soon as possible.
  • Plug-in devices that use power from an outlet are typically carbon monoxide will be labeled as such.
  • Some alarms will be two-in-one, sensing both smoke and carbon monoxide with a separate 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 your best bet.

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

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

  • Install carbon monoxide detectors near sleeping areas: CO gas exposure is most likely at night when furnaces have to run constantly to keep your home comfortable. As a result, all bedrooms should have a carbon monoxide alarm installed around 15 feet of the door. If two bedroom doors are less than 30 feet apart, a single alarm is enough.
  • Add detectors on every floor: Dense carbon monoxide gas can become caught on a single floor of your home, so try to have at least one CO detector on each floor.
  • Have detectors within 10 feet of the internal garage door: Many people unsafely leave their cars running in the garage, leading to dangerous carbon monoxide gas, even while the large garage door is completely open. A CO sensor immediately inside the door—and in the room up above the garage—alerts you of elevated carbon monoxide levels entering your home.
  • Install detectors at the correct height: Carbon monoxide is a similar density as air, but it’s commonly pushed up by the hot air released by combustion appliances. Putting in detectors near the ceiling is a good way to catch this rising air. Models with digital readouts are best installed at eye level to make them easier to read.
  • Add detectors around 15 feet from combustion appliances: A few fuel-burning machines produce a tiny, harmless amount of carbon monoxide as they first start running. This disperses quickly, but when a CO detector is positioned too close, it may lead to false alarms.
  • Have 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 strong sunlight, around air vents, or close to heat-generating appliances.

How do I test/troubleshoot a carbon monoxide detector?

Depending on the model, the manufacturer might suggest testing once a month and resetting to sustain proper functionality. Also, replace the batteries in battery-powered units twice a year. For hardwired units, replace the backup battery every year or when the alarm is chirping, whichever comes first. Then, replace the CO detector entirely every 10 years or according to the manufacturer’s guidelines.

How to test your carbon monoxide alarm

All it takes is a minute to test your CO sensor. Check the instruction manual for directions individual to your unit, understanding that testing follows this general procedure:

  • Press and hold the Test button. It will sometimes take 5 to 20 seconds for the alarm to start.
  • Loud beeping indicates the detector is functioning correctly.
  • Release the Test button and wait for two fast beeps, a flash or both. If the device keeps beeping when you release the button, press and hold it again for five seconds to stop it.

Swap out the batteries if the unit fails to perform as expected for the test. If replacement batteries don’t help, replace the detector entirely.

How to reset your carbon monoxide alarm

You only have to reset your unit when the alarm goes off, after a test or after changing the batteries. Certain models automatically reset themselves within 10 minutes of these events, while other alarms need a manual reset. The instruction manual should note which function is applicable.

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 notice a beep or see a flash, start the reset again or replace the batteries. If nothing happens, troubleshoot your carbon monoxide alarm with help from the manufacturer, or replace the detector.

What do I do if a carbon monoxide alarm starts?

Use these steps to protect your home and family:

  • Do not ignore the alarm. You won’t always be able to detect hazardous levels of carbon monoxide until it’s too late, so assume the alarm is functioning properly when it goes off.
  • Evacuate all people and pets as quickly as possible. If you’re able to, open windows and doors on your way out to attempt to dilute the concentration of CO gas.
  • Call 911 or your local fire department and explain that the carbon monoxide alarm has started.
  • It’s wrong to think it’s safe to reenter your home when the alarm is no longer beeping. Opening windows and doors may help air it out, but the root cause could still be producing carbon monoxide.
  • When emergency responders come, they will go into your home, measure carbon monoxide levels, check 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 schedule repair services to keep the problem from recurring.

Get Support from Service Experts Heating, Air Conditioning & Plumbing

With the appropriate precautions, there’s no need to be afraid of carbon monoxide inhalation in your home. In addition to installing CO alarms, it’s important to maintain your fuel-burning appliances, namely as winter gets underway.

The team at Service Experts Heating, Air Conditioning & Plumbing is ready to inspect, clean, diagnose and repair malfunctions with furnaces, boilers, water heaters and other combustion appliances. We understand what signs suggest a possible carbon monoxide leak— like increased 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 & Plumbing for more information.

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