Just do these simple things:
Check monthly – press the “Test” button
Vacuum monthly – dust, lint, pet dander can clog up the filter.
Change the battery – Every year or buy a 10 year battery.
Change the device every 10 years – when checking the battery, look to see if there is a date. If the date is 2003 or prior, go buy a new device.
You may still hear the noise if you hit the test button, but the sensor is probably bad.
Smoke alarms are not expensive and they do alert you if there is smoke in the house. Put one inside each sleeping room and one on each level. Don’t put it near the kitchen.
Stay safe – check your smoke alarms often. Not only is October Breast Cancer Awareness month, it is also Fire Prevention month.
Thank you for your time.