A recent call came from a house the fire department had just left. A 60 year old switch (pictured below) had overheated and begun to burn. The homeowner smelled something and called the fire department. If she had not been home, it could have been very bad.
She was perplexed because the smoke detector didn’t do its job. Pushing the test button sounded the horn but it had lost its ability to detect smoke a long time ago. Ten years is what manufacturers recommend for the life of a detector. They aren’t trying to sell more detectors, they’re trying to save lives!
Pushing the test button and hearing the horn on a 10+ year old detector only means the horn works. That is no guarantee it will detect smoke.
Newer detectors are available with a ten year battery. That means no yearly batteries to replace. After 10 years, simply buy a new detector. That is the safest investment for any home.