Should my First Alert carbon monoxide detector be red?

Author: Bart Marks  |  Last update: Sunday, March 22, 2026

First Alert CO600 Plug-In Carbon Monoxide Detector A: That is the power light. It is normally solid red and flashes when there is a problem.

Why is my First Alert carbon monoxide light red?

On First Alert® carbon monoxide alarms, the red light flashes to show the Carbon Monoxide Alarm is properly receiving battery power.

Why is my carbon monoxide detector beeping with red light?

If it beeps four times and then is silent for 5 seconds before repeating, and the red LED is on steadily, then it's a carbon monoxide detection. If it beeps continuously and the red LED is flashing then it's a propane detection. You can mute it for 3 minutes by pressing the mute/test button.

Should a carbon monoxide detector be red?

First Alert CO600 Plug-In Carbon Monoxide Detector

A: That is the power light. It is normally solid red and flashes when there is a problem.

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.

FIRST ALERT BRK SC9120FF Hardwired Smoke and Carbon Monoxide CO Detector Review

Why is there no green light on my carbon monoxide detector?

If the red or green light on your CO detector is illuminated, that's a sign that the unit has power. If the light is off, replace the batteries and follow the reset steps.

How can I be sure my carbon monoxide detector is working?

How to test your carbon monoxide detectors to ensure they are working properly? To test your carbon monoxide detectors, press and hold the test button on the alarm. The detector will sound 4 beeps, a pause, then 4 beeps for 5-6 seconds. Refer to the user manual for your specific model.

What does a First Alert carbon monoxide alarm sound like?

Smoke alarms alert you with three beeps in a row. Carbon monoxide alarms alert you with four beeps.

What color should my First Alert carbon monoxide detector be?

On First Alert carbon monoxide alarms, the red light flashes to show the CO alarm is properly receiving battery power. If you do not see the red light flashing, change the batteries in the alarm immediately.

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.

Where is the best place to put a carbon monoxide detector?

The International Association of Fire Chiefs recommends a carbon monoxide detector on every floor of your home, including the basement. A detector should be located within 10 feet of each bedroom door and there should be one near or over any attached garage.

Why is there a red light on my smoke alarm?

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.

Why is carbon monoxide red?

It comes from high levels of carboxyhemoglobin in the blood. Unfortunately, it is often a postmortem examination that reveals such a bright red coloring. The level of carbon monoxide in the blood required to get the skin to that color is so high that it is nearly always fatal.

How to tell if a carbon monoxide detector is going off?

To warn of dangerous CO levels, most detectors will beep 4 or 5 times in a row about every 4 seconds. Do not mistake dangerous levels of poisonous gas for a detector with low battery!

How do I know if my First Alert smoke carbon monoxide detector is working?

It is important to test this unit every week to make sure it is working properly. Using the test button is the recommended way to test this Smoke/CO Alarm. You can test this Smoke/CO Alarm: Press and hold the Test/Silence button 3-5 seconds until unit starts to alarm.

Does the fire department charge to check for carbon monoxide?

In most areas, the fire department does not charge to respond to carbon monoxide alarms or to check for the presence of CO in a residence. However, policies can vary depending on the jurisdiction or specific fire department. It's always a good idea to contact your local fire department for specifics on their policies.

What can falsely set off a carbon monoxide detector?

Common causes of false alarms of carbon monoxide:
  • Close to cooking sources (10 feet minimum)
  • Close to sources of humidity (10-20 feet)
  • Near fireplaces.
  • Near water heaters.
  • Near furnaces.
  • Located in a poorly ventilated location like a garage, kitchen, or closet.

Should my carbon monoxide detector have a red light?

On many carbon monoxide alarms, the red light flashes to show the CO alarm is properly receiving battery power. For these alarms, when you do not see the red light flashing, change the batteries in the alarm immediately.

How do I make sure my carbon monoxide detector is working?

If you're wondering how you can check that your carbon monoxide detector works, the answer is simple: testing. You should test your CO detector monthly to ensure your family's safety. The test button is the best way to test it because it will tell if the alarm is still sounding.

What does solid red light on First Alert smoke detector mean?

Look for the detector that has a solid red LED light. That means it is the detector that is in alarm condition. Once you find it, remove that detector by unplugging the power to it and take the batteries out.

What to do if a carbon monoxide alarm goes off and then stops?

If you have a carbon monoxide detector chirping and then it stops, it's important to take the situation seriously, even if the alarm is no longer sounding. Even if the alarm has stopped, get everyone out of the home to a place with fresh air.

Who can test my home for carbon monoxide?

Some municipal fire departments and utility companies will come to your home and check for carbon monoxide for free or at reduced rates. The main tool used in these tests is an electronic portable toxic multi-gas monitor.

How to detect carbon monoxide with iPhone?

Go to the Home app on your iPhone or iPad. , then tap Home Settings. Tap Safety & Security. Tap Sound Recognition, then turn on Smoke & CO Alarm.

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