Smoke alarms need replacing every 10 years as the sensors become less effective over time. If they have no expiry date printed inside, they are older than 10 years.
You can tell how old your smoke detector is – they have a date of manufacture printed on them. If they don’t have a date, it means they are more than 10 years old, from a period when the dates weren’t required, and you should definitely replace them.
- Do Smoke Alarms Have An Expiration Date? @ GetSafeAlarms.com
Excerpt: All smoke alarms have a recommended service life of 10 years. Replace your smoke alarms at this time or sooner if they are not functioning properly. Look for the manufactured date on the back or inside the alarm.
- Looking after your smoke alarm | Smoke Alarm and Detectors @ Fire Service
Excerpt: After 10 years it’s best to get a whole new alarm.