Do smoke detectors and carbon monoxide detectors look the same?

Author: Zaria Gleichner  |  Last update: Friday, November 21, 2025

Carbon Monoxide Detectors Don't be confused! A carbon monoxide detector may look just like a smoke detector, but the two are different and they serve different purposes.

How to tell the difference between a carbon monoxide detector and a smoke detector?

Here's a simple guide: Smoke alarms alert you with three beeps in a row. Carbon monoxide alarms alert you with four beeps. A single chirp means the battery is low or the detector should be replaced.

What does a carbon monoxide detector look like?

Carbon monoxide detectors are typically small, round, and white. They typically have two holes for mounting screws, a center button to test the device, and a digital display that shows the carbon monoxide level in the home.

What does a smoke detector look like?

Smoke detectors/alarms are usually housed in plastic enclosures, typically shaped like a disk about 125 millimetres (5 in) in diameter and 25 millimetres (1 in) thick, but shape and size vary. Smoke can be detected either optically (photoelectric) or by physical process (ionization).

How to tell if carbon monoxide is leaking?

What Are Signs of Carbon Monoxide in Your Home?
  1. Yellow or orange flames coming out of your gas appliances instead of the usual blue flame.
  2. Dark and sooty staining on or around gas appliances.
  3. Pilot lights that frequently blow out.
  4. Increased condensation on windows.
  5. Solid fuel fires burn much slower than usual.

What Most Homeowners Don’t Know About Carbon Monoxide Detectors

What does a smoke detector sound like?

If your smoke alarm detects smoke, it will sound a very loud, 3-beep alarm pattern. Don't panic; stay calm. Follow your family escape plan. Get out of the house as quickly as possible.

What color are smoke detectors?

You will notice two different lights on your smoke alarm:
  • A steady green light shows the alarm is being powered.
  • A red light that flashes once a minute shows the alarm is working.

Is it better to have separate smoke and carbon monoxide detectors?

We recommend that you use a combination of detectors in your home for complete protection.

Do smoke detectors blink red?

Some smoke detectors blink red constantly, indicating they're working properly. If the light blinks red and chirps, your battery may be running low.

What are two warning signs of carbon monoxide poisoning?

The most common symptoms of CO poisoning are headache, dizziness, weakness, upset stomach, vomiting, chest pain, and confusion. CO symptoms are often described as “flu-like.” If you breathe in a lot of CO, it can make you pass out or kill you.

What color should your carbon monoxide detector be?

These simple detectors are pieces of cardboard with a small orange-colored circle in the middle. If there is a high-level of carbon monoxide in the vicinity, the circle changes color from orange to black.

Are there smoke detectors that also detect carbon monoxide?

Combination smoke & CO detectors provide 2-in-1 protection against both threats in one, convenient alarm.

What if the carbon monoxide alarm goes off but no fire?

False or nuisance alarms are when your smoke detector or CO alarm goes off, but there is no presence of smoke or carbon monoxide in your home. However, if your smoke or carbon monoxide detector sounds indicating an emergency and you are not certain it is a nuisance alarm, evacuate the home and call 9-1-1.

Should I be worried if my smoke alarm goes off for no reason?

Sometimes, smoke detectors will keep going off for no reason when they have reached the end of their life span. Fire alarms have a lifespan of about 10 years, after which they will need to be replaced. Smart smoke detectors can help eliminate some of the annoyances related to false alarms.

How long will a smoke detector chirp before it dies?

In addition, it can take days for a battery to completely drain, and the chirping will continue throughout that time. How long does it take a smoke alarm to stop chirping? An alarm will continue to chirp for at least seven days after its battery has died.

Does carbon monoxide rise or sink?

You should also place a detector in any room situated directly above your garage. The specific gravity of Carbon Monoxide is 0.9657 (with normal air being 1.0), this means that it will float up towards the ceiling because it is lighter than regular air.

What does 4 beeps mean on carbon monoxide?

What Does an Emergency Alarm Chirp Mean? This meaning is probably the most self-explanatory. When your carbon monoxide detector chirps 4 times in a row and pauses, this means it has detected unsafe levels of carbon monoxide. This means your entire household should evacuate immediately and seek fresh air.

Why did my fire alarm randomly go off in the middle of the night?

Why did my fire alarm randomly go off in the middle of the night? This is likely due to one of the common causes like low battery, dirt buildup, humidity, or insects interfering with the sensor. Test the alarm and clean it thoroughly to try and resolve the issue. Make sure batteries are fresh and secure.

Do smoke detectors always have a green light on?

How to Tell If Your Smoke Alarm is Working. Hardwired units will have a steady green LED light to show that it's receiving AC power. Battery-operated units will have a quick flash every 30-45 seconds. This does not necessarily mean the alarm is working.

Where to put a carbon monoxide detector?

Where should you place a carbon monoxide detector?
  1. Outside of each bedroom or sleeping area.
  2. Inside an attached garage.
  3. On every floor, including the basement.
  4. At least 10 feet from the garage door leading to your home. ...
  5. At least 15 feet away from gas-burning appliances, like fireplaces or stoves.

How do I identify my smoke detector?

You can do so by taking the smoke alarm down and look at the back for either “Photoelectric” or “Ionization,” or a symbol with the letter “P” or “I” on the back. Once you figure out which type you own, purchase the other type and install one next to each unit.

Why do I hear chirping in my house?

Intermittent beeps and chirps in your home may come from smoke or CO alarms that need your attention. Sometimes, other appliances in the home can cause a chirp as well. Here's what you should try if you can't find the source of the chirp. Check your smoke alarms.

Why is my house beeping every 30 seconds?

A set of four loud continuous beeps means carbon monoxide is present. A single chirp – repeating every 30 to 60 seconds – means your alarm battery is low and needs to be changed.

Previous article
Can a P-trap be too deep?
Next article
How long can an oven stay on?