Hi everyone! I need some help finding a smoke detector that has mounting holes exactly 3.5 inches apart. My ceiling has holes sized that way, and I'm struggling to find a detector that fits. If anyone has suggestions or knows where I can find one, I would really appreciate it!
4 Answers
Most smoke detectors come with slotted holes on their mounts, which allows them to fit a variety of box sizes. You might be overthinking it a bit!
I had some First Safety detectors that died early, and their customer service replaced them for free. I tried just sliding them onto the existing mount, but they didn't fit, so I replaced the entire mount. Only one screw is needed to hold the bracket, so it wasn't too difficult to swap out!
Hardwired smoke detectors are generally designed to fit those mounting boxes. If you choose that route, you should be good!
That's weird, I was advised to stick with battery types instead of hardwired ones. Is there a reason for that?
If you're not planning on using a hardwired detector, I recommend covering your current box with a round cover plate. Then, you can install any smoke detector you prefer in a different location.

I did find a Kidde model, but unfortunately, the holes were only 3 inches apart.