Kidde smoke alarm interconnect problem

I was testing the smoke alarms at my Grandparents’ house today and most of the smoke alarms were fine but 2 of the 3 Kidde i2040A smoke alarms had the interconnect not working. This surprised me because I had just checked them a month earlier and they were all working fine. I did make sure that it was the detectors at fault and not the wiring. Is this a common problem?

What should I replace them with. I was thinking about replacing it with a First Alert 9120b for better reliability but I’m not sure if the interconnect would work with the other kidde smoke alarms in the house. Would this work? If not, what else would be a good, reliable, and cost effective option.

You will have to replace all the detectors as different brands can’t be interconnected together. I’d recommend the BRK/First Alert 3120B as it’s dual-sensor (ionization & photoelectric), which should be able to detect any type of fire that may start (better than the ionization-only i2040A & 9120B for sure).

1 Like

What Kidde model would you recommend as I’m trying to avoid replacing all of them.

I’d say BRK/First Alert is better reliability-wise given all the recalls Kidde’s had to issue over the years but when it comes to the latter I’d say the Pi2010 would be good as it’s also dual-sensor (the existing detectors will still be ionization-only though, thus limiting what they can detect).

1 Like

Thanks! I will probably do a Kidde PI2010 or a Kidde P12040.

Sure thing!

If you can’t afford dual-sensor photoelectric is definitely the next best type.

This could just be a dead battery. The interconnect circuit on a smoke detector is 9v, so if the battery is dead, it can’t output it. One way to check is if the green led is blinking slowly. If so, there’s a dead battery on the detector. Replace it, and see if it works. I’ve had a similar thing happen to the brk smoke detector in my basement

I replaced the batteries and tried testing them with a multimeter with the pins on the back. There was 0v coming out. They were also not accepting the input from working ones. I also have taken the battery out of these smoke alarms before and the interconnect still worked so I guess that doesn’t apply to all alarms.

Then you should replace them

Not sure if I’ve ever heard of the green LED indicating a dead or missing battery: most of the time a detector will chirp instead.

It chirps if the battery is low, but it does the led thing if it’s completely dead

Maybe some Kidde detectors but from what I’ve seen most detectors will chirp whether the battery is dead, low, or missing, as they apparently can’t tell the difference.

I did end up replacing them with Kidde P12040’s.

I had one with the same problem. But replaced it with a First Alert SC7010BV. Kidde is just junk.

We’ve got Kidde interconnected smokes. We’ve never experienced an interconnect problem with them, but we are on the second batch of them due to the original three failing one by one. Kidde is just junk due to failing products. At least they’re not as bad as Nest Protect.

And Thats why I’m replacing them with First Alert.