Daylight Savings Time this Weekend!
My wife & I were checking out our smoke alarms last weekend. A cake had spilled in the oven, onto the heating elements, and the kitchen became slightly smoky. But no alarm sounded. So we put in a new battery and tested the alarm - no sound. We tested the battery - it was still good. We tried the battery in another smoke alarm - no sound. At this point we were quite puzzled. What was going on? Then my wife figured it out - just pressing the test button was not enough, we had to press and hold the test button to trigger the alarm. Ah! Mystery solved.