How to Troubleshoot a Hard-Wired Home Smoke Detector

Dirty vents in the head cover of the hard-wired smoke detector can cause the alarm to sound repeatedly. Twist the head cover off the detector with a counterclockwise motion--a ladder may be needed in order to reach the detector. Wipe the edges and the inside of the head cover with a paper towel. Blow through the vents in the head cover with bursts of compressed air. Dip a cotton swab in distilled alcohol. Rub the moistened end of the cotton against the edges of the vent slats on the head cover. Blow out the vents with bursts of compressed air. Twist the head cover back on the detector with a clockwise motion.

If the detector's "ready" light no longer is illuminating every 30 seconds or so, the electrical line supplying power may not be functioning. Go to the fuse box and aim the beam of the flashlight at the fuses. Look for a darkened glass panel on a fuse, compared to the clear glass panel that is normal. Remove the fuse that has a darkened glass panel and replace it with a new compatible fuse. Return to the detector to find the "ready" light once again illuminating. If circuit breakers are used instead of fuses, play the flashlight across the circuit breakers until you come to the one that is pointing down, compared to the others that are all pointing up. Push the down-pointing circuit breaker up.

A "chirping" sound coming from the hard-wired home smoke detector indicates that the alarm has sounded and that the detector needs to be reset. Verify first that the alarm was a false alarm by checking the immediate area and then the rest of your home. Press the "Reset" or "Test/Silence" button on the side of the detector--the actual name may vary depending on the make of the detector. Release the button when the horn sounds. The horn will cease sounding after a few seconds have passed, with the detector now functioning normally.