Testing a Carbon Monoxide Detector or Smoke Detector
Smoke detector testing and carbon monoxide detector testing procedures vary from model to model. Different models have different test sound patterns and, if equipped, light patterns. Some smart-compatible smoke and carbon monoxide detectors allow testing through an app on your phone or tablet.
We have general steps for manually testing a standard smoke or carbon monoxide detector. Follow the steps in the manual for your specific model so you know exactly how to check the smoke detectors or carbon monoxide detectors in your home. Can’t find your smoke or carbon monoxide detector manual? Note the model number on the device and check the manufacturer’s website.
How Often Should You Test a Smoke Detector or CO Detector?
Test all smoke detectors and carbon monoxide detectors weekly, including:
How Can You Test a Carbon Monoxide Detector or Smoke Alarm?
- Let other residents of the home know you’ll be testing the smoke detector or carbon monoxide detector. Have someone in the home as far away from the device as possible to ensure they can hear the alarm.
- Check your manual for the sound or light test pattern for your device.
- Locate the test button on the device. On most devices, TEST, TEST/SILENCE, etc. is imprinted on or near the button. If you’re not certain of the button location, check your manual.
- Press the test button for five to 10 seconds or until the alarm horn sounds. There should be a series of alarm sounds or the alarm might sound only while you press the button. If the device includes an alarm light, it should flash.
- A smoke or carbon monoxide alarm is very loud, so you shouldn’t be close to the device any longer than necessary. If the alarm horn pattern continues after you release the button, step away from the alarm. If you’re on a ladder, climb down carefully.
- Confirm that the sound and light pattern matches the expected pattern for your device.
- Repeat the process for all the devices in your home.
Testing Interconnected Smoke and Carbon Monoxide Detectors
If you have interconnected smoke and carbon monoxide detectors, test each individual device. In addition to verifying that each individual unit activates, make sure that all units activate when one does.
What to Do if a Smoke or CO Detector Doesn’t Activate
Here’s what to do if your smoke or carbon monoxide detector doesn’t test as expected:
- If the alarm horn or alarm light doesn’t activate on a device with disposable batteries, install new batteries. If the alarm doesn’t activate with correctly installed fresh batteries, replace the device immediately and install new batteries. Dispose of the old device properly.
- If the alarm horn or alarm light doesn’t activate on a hardwired device, plug-in device or a device with a built-in battery, replace the device immediately and install fresh back-up batteries, as necessary.
Check your manual for specific details on detectors that don’t pass testing.
Other Smoke and Carbon Monoxide Detector Maintenance
As you’re testing a smoke or carbon monoxide detector, there are a few other things you should do:
- Vacuum the device exterior using an attachment with a soft brush, as necessary.
- While many devices alert you when they reach the end of their lifespan, it’s a good idea to check the manual for the lifespan of each device and look for the manufacture date on the device. Replace any device that’s past the end-of-life point. Your manual may have a procedure for permanently deactivating the device. Dispose of the device properly. See our articles, Smoke Detector & Carbon Monoxide Alarm Buying Guide and How to Install a Smoke and Carbon Monoxide Alarm for tips on finding and installing replacements.
- If you haven’t replaced the batteries in your smoke or carbon monoxide detector in the past six months or you can’t remember if you have, replace them now according to the manufacturer’s specifications. Remember, hardwired and plug-in devices often have backup batteries that you need to replace.