Smoke detector shelf life

We all know that residential ionization smoke alarms are supposed to last 10 years. But many ion detectors out in the field were installed decades ago. Are there different guidelines for commercial detectors, or is it simply a case of “it’s not actually broke, so don’t fix it”?

Also, is the longevity any different for photoelectric detectors? One would think they’d last longer since there’s no radioactive material, but every source seems to say “10 years”, and this source even says 5:

I know that ionization smoke detectors do degrade (as the source breaks down and decays) but for optical smoke detectors, I still have a 70’s Ademco photoelectric/optical that still works to this day, and I do not really know if “Photoelec” smokes have a shelf life.

We have a few photoelectric smoke detectors over here that were installed when I was in elementary school. All we have to do is replace the batteries in them and they keep on working like the Energizer bunny.

My dorm supplied 2 photoelectrics when I moved in. I just change the batteries every now and then and BOOM! Protected!

(these were also installed in 2019)

I think that what Simplex 2903-9101 was referring to was older detectors that were installed years ago and not newer ones. Mine would be a good example because ours were installed probably around 2000.

[quote="Simplex 4051" post_id=86074 time=1580483510 user_id=18]

I think that what Simplex 2903-9101 was referring to was older detectors that were installed years ago and not newer ones. Mine would be a good example because ours were installed probably around 2000.

[/quote]

OH.

For commercial detectors, I write them down or recommend replacement when you cannot test the sensitivity on them. Smoke Detector Sensitivity has been looked at a lot more in recent years here, and the fire inspectors want them on the reports and any detectors replaced that cannot test for sensitvity (IE, the Edwards 6249C). For smoke alarms, I write them down or replace them if they are 10 years or older. As well, has become a thing for the fire department. The one condo we started servicing, all had smoke alarms from the 80s. Needless to say, before we could replace them, the fire department had a surprise inspection. & They went and replaced every single detector that was from the 80s or out of date.

I mean IMO I don’t think there is a shelf life, like the old extinguishers. They require replacement or recharging after 6 years, but they’re still good, I keep expired extinguishers around my house. But I just go by what I know from working in the field.

So basically smoke detectors never really stop working completely they just get less effective over time even if you do keep them well-maintained?

The sensors inside wear down over time. Even when it’s not going off it’s still working so if the detector is decades old my guess is it wouldn’t be as effective. Just like any device it breaks down over time although putting a fresh set of batteries in it would always help. My First Alert SA76RS which I got through this forum is one I actually trust more than the functioning detector I have in my apartment (Kidde). The SA76RS works perfectly when tested with candle smoke within just a few seconds and it is from 1977 (going by the serial number). I also trust the older ones over the ones of today. I wished they had have kept the old squealer horns over the piezos. Squealer horns made you jump 10 feet in the air when the sounded and no way I would ignore it. But of course piezos cost less to produce and to companies money is more important than safety. Kinda sad eh! Bye the way I love the sound of the RS, which was a childhood fear!

I guess when looking back on stuff like that, you tend to like the sound now even though you were afraid of it when you were younger. That is the case with me and fire alarms actually. :stuck_out_tongue: