We recently received a smoke detector question from a customer. She had some hard-wired smoke detectors installed in 1996 and wondered about replacing them. Our answer is yes, she should replace them since they are 20 years old. We recommend replacement every 7-9 years just to be safe.
If you don’t know the age of yours, take them down and look at the back of the case. The manufacturer may have printed the date of manufacture on them. You might also find a label inside the battery door.
If you don’t find a date, look at the color of the plastic case on your smoke detectors. If they are yellow, chances are they are ready to replace them. Many plastic cases are made of polypropylene, impact styrene, and ABS. Those plastics had a tendency to discolor over time from oxidation. Many people think the yellowing is due to smoking, which might be true, but even non-smokers see the same color change over time. If your detectors have a grease or dirt buildup, that can account for some yellowing. However, if they aren’t dirty and are still yellow, that means they are old. This is a visible design feature from manufacturers that gives people a reason to replace them at an appropriate age.
There are two kinds of smoke alarms. The first uses ionization detection, which is faster for flames. The second uses photoelectric detection, and they are faster for smoke or smoldering fire. Because they are different, the best type is the combination which uses both technologies.
Changing smoke detectors is relatively fast, which makes the labor cost low. Also, you can buy new detectors for $20 or less, so the total replacement cost is very reasonable. When you compare that to the value of the lives of your family, updating your smoke detectors is a bargain.
Some homeowners can change their own smoke detectors by just unplugging the old and plugging in the new. However, if you need assistance with the wiring or in reaching them at a high location, give us a call. We’ll be glad to help with any electrical issues you have.
For additional information, visit the National Fire Protection Association.