Smoke alarms went off right after lightning struck?

Hey guys.

So it was somewhat past 1 in the morning, there is a severe thunderstorm happening, and I’m on my phone browsing Reddit and stuff. All of a sudden, lightning blasts to the house basketball hoop right beside my room, causing a crater with large gunshot-like noises, and the smoke alarms in my house (older BRK ionization alarms) start beeping for about 10 seconds before shutting off. My theory is the vibration of the impact set the horns off.

So now I’m wondering: has there been something other than smoke that set your smoke alarms off; something like this or no?

One time, in my childhood home, some earwig or bug ended up in the alarm itself, which set off all 7 kidde alarms. I still have the one that was initially alarmed.

I remember two instances of my home’s smoke detectors activating without smoke.

The first instance was back between 2004-2013, where our family had a really sensitive First Alert smoke detector. It was a ceiling-mount model, probably from the 80s or 90s, located just outside the kitchen area in a short hall connecting the basement steps to the garage. The smoke detector would sound every time my family was cooking food with a strong odor (not necessarily from smoke), although it was more likely due to steam from the cooking getting too close to the detector itself.

The second instance was between 2013-2017, when our family was living in a two-story condo. All the smoke detectors in our home were hardwired to each other, so whenever one detector sounded, all of them would trigger. The smoke detector in the master bedroom was prone to getting set off if the ceiling fan, which was left running almost all the time to circulate air, was switched off. I believe the fan’s blades accumulated dust over time, and didn’t get cleaned as often as they should have. Consequently, the dust from those blades would drift over to the detector and set it off.

Do any of the smoke alarms have a heat element in them? I suspect that maybe the vibration shorted the two contacts within the element, thus activating the system.

Never happened to me. Closest would be when lightning at my elementary school struck and caused the alarms to go off. It wasn’t a bad thunderstorm and the lightning moved away but it was down-pouring HEAVILY at the time. I was in 3rd grade.

Brace yourselves… this is a very long post.

Funny you should bring this up, as that a few weeks ago, one of the First Alert SA67Ds in my house started going off randomly. It’s not the one that had been replaced by the Kidde/Code One smoke alarm (the one in my room) almost a year ago at the time of posting this. Instead, it was the one in the basement of my house (yes, the very same room where some of my FA tests involving horns and/or horn/strobes, except it was installed near the top stair).

Here’s what happened. One night, I was in the middle of editing a video (or at least I was trying to), then all of a sudden, the smoke alarm in the basement was going off. I’ve noticed that I heard what sounded like an old smoke alarm going off. At first I thought it was coming from the TV (yes, I know that’s a bad thing to assume), but then I realized that it was coming from the basement (see sidenote), so I rushed to the family room (that’s where the door leading to the basement is located) to see if there was any smoke or fire. It didn’t seem like any (neither my mom and I didn’t bother turning on the basement light at that moment). It eventually did stop beeping on its own (my mom was trying to find a way to silence it, but since that smoke alarm doesn’t have a “hush” feature, there was no way to do it other than to remove the battery).

Ultimately, my mom had removed the battery from the smoke alarm, and then took the unit off the wall (which, at the time, I thought that wasn’t such a good idea).

From that scarring moment, I was genuinely worried, since laundry was being done before the smoke alarm went off. I was so worried that I ended up taking my shoes to my room before I went to sleep that night (in case a fire broke out in the basement, which, fortunately, didn’t happen). I’ve never heard it go off prior to this (at least for when it was in the basement 'cause I believe that it may have been swapped for another smoke alarm in the house at some point).

The following week (since that night happened to be my dad’s last night of his business trip the week before), the battery was re-inserted in the smoke alarm and then the alarm itself was reinstalled. But about 10 seconds later, the smoke alarm started going off again. Then I realized that there was a problem with the smoke alarm itself.

Shortly after that, the unit was once again taken off the wall, except this time, the battery wasn’t removed. But just days later, it started going off again, despite not being mounted back on to the basement wall near the top stair. So, my dad had to remove the battery and ultimately had to buy new smoke alarms from the store. The new smoke alarms he bought were a pack of two First Alert smoke alarms (I believe these are SA304s since they looked like the SA304 that I had acquired back in either 2009 or 2010). At the time of writing this, the alarms aren’t out of its packaging yet, but I really hope they get put to use soon (the copyright date on the package is from 2018).


Earlier this morning, I had asked my dad what was wrong with that smoke alarm. Based on what he had told me, it had something to do with the sensor (he wasn’t sure of the exact cause, but it’s probably a rough guess).

This is most likely why you need to replace your smoke alarms once every ten years! If your smoke alarm starts beeping (not chirping) and there doesn’t appear to be any presence of smoke or fire, check the back of the unit. If there is no date stamp on the back, chances are, they’re more than ten years old. But if there is a date stamp and it’s at least ten years old (or even if it’s getting close to being ten years old), definitely replace it.


How was I able to tell that the smoke alarm in the basement was going off? My house has a total of four smoke alarms: three of them are in three separate bedrooms respectively, and they are close to each other; and the other smoke alarm was the one in the basement, and the family room is not immediately next to my bedroom.

I think this has something to do with charges in the air and the way it affects ionization detectors. I do remember seeing a video on YouTube a long time ago where lightning struck close by and the smoke alarms in the house sounded for a short time.

Doesn’t happen with lightning, but sometimes when I’m doing inspections, I’ll find smoke alarms without batteries, & As soon as I put a fresh one in, the thing starts going off and won’t stop.

I assume these smoke alarms aren’t tied to any alarm system?