Late tonight, a mystery alarm went off for about 15-20 seconds. I was in my bedroom, and by the time I got to the source, it had stopped. My husband and I can’t figure out what it was. The sound was really loud, kind of like a braying noise, and it came in blasts of four. At first, I thought it was the CO2 monitor, but when I pressed it, it just gave off a loud chirp. So, it wasn’t that, and I’m not sure how that little monitor could make such a big sound.
For context, we have smoke alarms and a CO2 monitor. Our house uses natural gas heating and has solar panels. We also have Alexa devices and a Bose soundbar connected to Alexa. Any ideas?
Sometimes there can be a brief interruption in power when the utility company is working on the lines. It might not be long enough to reset the clocks, but it can be just enough to trigger some devices to alert when they turn back on. You can test this by flipping the fuses off and on for a second or two, and have your husband listen for the sound.
Another possibility is that your fire/CO2 alarms have backup batteries. They’ll make an annoying noise when the battery needs replacing. It starts off randomly and then increases in frequency. My alarms are all connected, so it’s always a fun game of ‘which battery is it’ when I only have a couple of fresh batteries left (I’ve got four or five of them around the house).