How to Test a Hard-Wired Smoke Detector

When it comes to safety, the U.S. Fire Administration considers a smoke detector one of the most important items you can have in your home. If you have moved into a house with a hard-wired smoke detector, you may think that since it is part of the electrical system it will alert you if there is a fire. Without testing it, however, there is really no way to ensure that your smoke detector will work.

Testing your smoke detector with a candle can ensure that it is working properly.

Press the test button to activate your smoke detector. The test button is typically visible on the underside part of the casing. In some models, this button may be clear or illuminated. If working properly, the alarm should start immediately and continue to sound until you remove your finger.

Light a candle or incense stick. Hold a lit candle 12 to 18 inches below the smoke detector to determine if it is working properly. Make sure you do not hold the candle too close to the smoke detector since you may accidentally melt the casing or damage the smoke detector's internal parts.

Use an assistant to check the other smoke detectors in the house while you test the unit. Many hard-wired smoke detectors are designed so that when one goes off all of the others will go off as well. If yours is wired this way, an assistant can help you determine all units are operating properly.

Things You Will Need

  • Candle
  • Incense stick (optional)
  • Assistant


  • Smoke detectors usually have small openings or slatted grates, where the actual detector part of the device is located. While testing your smoke detector, make sure the grates are open and not blocked by hair or dust.
  • It is generally recommended that you check your smoke detector each month by pressing the test button and at least every three months using a burning material such as a candle to ensure that the smoke detector will actually work if there were a true fire.

About the Author

Based in Atlanta, Casey Kennedy has been writing online content since 2009. She specializes in writing about small business, careers, real estate, and ecommerce. She also enjoys writing about a variety of other subjects, including home improvement, gardening, and pet care. She attended the Academy of Art online, studying interior architecture and design while pursuing commercial flight training at Aviation Atlanta in Georgia.