What are the chances? (smoke alarms)

[Alex Franke]

Shortly after I got home tonight, I heard the smoke detector chirp, so I took it down to change the battery. In the middle of that process, I heard the upstairs smoke detector chirp. I figured I just heard the wrong one the first time, so I put the old battery back in the one I had open, and went upstairs to put the fresh battery in the other alarm.

In the middle of that one, I heard the downstairs alarm chirp again. Better safe than sorry, so I got another battery and changed them both. Problem fixed, but I'm completely puzzled.

Both of the old batteries came in at less than 8V, so they did need to be changed. They were different brands, and we install them as needed (rather than every time the time changes), so installation was staggered, too. I'm absolutely stunned that they both happened to die at virtually the same time...

Am I missing something?

[LinuxRandal]

Have you ever had something set them off, that could have drained both? (burning on the stove, soldering too close to them, etc)

[leehljp]

It was the humidity!



Hey, we have to blame it on something! This is the kind of thing that drives non-logic people crazy. Two unrelated events happening simultaneously cause misdiagnosis in science, medicine, computers, love . . . you name it. Shucks, this has happened to me so often that I have come to be prepared for 2 and 3 simultaneous events as I diagnose a problem. Experience and age does that to some people.

[Alex Franke]

Have you ever had something set them off, that could have drained both? (burning on the stove, soldering too close to them, etc)

The downstairs alarm has gone off a couple times due to some overly enthusiastic cooking, but we've never managed to set the upstairs on off like that.

It was the humidity!

...or the heat -- it's been getting pretty hot in these parts lately!

I like this one better than the alien theory I've been pondering

[Uncle Cracker]

I have eight of them in my home... They all are wired into a dedicated AC circuit, and each has a 9V battery backup. Somehow, they communicate with each other, as when one of them goes off, they all do. Unfortunately, this also means when the battery is weak in one of them, they all chirp, too. I just make it a habit to replace the batteries in all of them on New Year's Day (right after my hangover clears up...).

[final_t]

overly enthusiastic cooking

I am so using that next time, instead of our standby, "dinner's ready!"

Okay, fire alarms in all the usual places, now a show of hands for the actual fire extinguishers where you can use'em?

[shoottx]

Be glad it was batteries.

About 6 mos. ago a smoke alarm started chirping, it was centrally wired with a battery back up. Changed the battery, it tested bad, and thought the problem was fixed. Next night about 2:00 am the alarm starts chirping again. After messing around with the alarms for a couple of days, I started some research and found out the smoke detectors also have a life expectancy. We were into twice the time of thier life expectancy. So it was time to replace all of them. Of course after 15 years the original model had been discontinued, but the new model fit right on the old base. Wooo Hooo no painting or changing bases.

Check the life expectancy of your smoke detectors. They may have deteriorated and might not be as effect as necessary.

[cabinetman]

It's called "coincidence", which is a phenomenon not easily understood and certainly not provable.
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