What the hell beeped?

We were awakened last night when something beeped three times. Got up, looked around, didn’t see anything obvious, so we went back to sleep. Again, three beeps about ten minutes later. This time, we got up, turned on all the lights and checked things. Nothing. So here is what it wasn’t:

Smoke alarms: all are hard-wired. If the backup batteries get low, they will persistently chirp one time until you either remove the battery or replace it.

CO detector: is in the bedroom and is very loud. Wasn’t that.

Refrigerator: will start beeping if the door is left open for a long time. Door was closed and internal temps were correct.

Home security alarm: no error messages on the screen, which will happen if anything goes wrong, from a dead detector battery to other faults.

Discharged phone battery: nope, doesn’t make that noise when going dead.

Temporary power glitch: the toaster oven will beep three times when power comes on after a momentary loss. But the settings also reset, which didn’t happen. Also, all the clocks are showing correct time.

Noise from outside the house: nope. It’s been so hot that all the windows were closed so the AC could keep things cool.

I’m completely flummoxed here. Nothing has beeped since that second time. Any ideas?

It wasn’t any kind of weather/medical alert via your cell phone? I have alerts turned on and, occasionally, I’ll get an unexpected and unrecognizable sound because of it.

Computer self-updating?

Any new electronics in the house? That would include appliances (small or large) and medical apparatus (which nowadays is often electronic for reasons lost to me).

If it’s my house, the annoying beeps in the middle of the night are from my weather station, which for some reason has an alarm on it. About every 2-3 years, someone jostles the “alarm on” button, and the default time is sometime in the middle of the night. I’m woken up by the damn thing beeping and it always takes me a while to figure out that’s what it is.

So my advice: look around your house for things-that-have-alarms-that-you-don’t-use and see if someone jostled them by mistake.

Whenever I hear some kind of random beep and can’t quickly find it, I just assume it was a device (ie tablet) in the house somewhere getting a notification. Other than my phone and computer there are three tablets (a Nexus and a Kindle Fire and a Kindle Reader). Any of them (not sure about the reader) can make the occasional beep and it’s easier to just assume it was one of them than to actually try and figure it out.

An old pager in a closet finally losing battery power.

No new electronics.

All computers shut down for the night.

No smart phones, so no alerts of any sort.

Kindles are charged.

I just noted that we got an email from ADT telling us that our alarm system appears to be operating just fine. Now I’m wondering if they sent some sort of line signal to it. But why would they do that in the middle of the night?

I have gone through this twice, it was the smoke detectors failing. No loss of power, batteries still read new on a meter. Kidde replaces all 5 in my house free of charge, all were still under warranty. The old detectors were only a few years old, they were installed new just prior to my wife and I buying the house.

Do you have any UPSes? Maybe your power went out briefly - just enough to trigger the UPS, but not long enough for any other devices, including your toaster oven.

Someone left their mug of hot water in the microwave?

My new(ish) microwave stops beeping after some period of time when you forget you’ve nuked something. Best feature ever!

Hot weather requiring the AC running all the time is an indication there may have been power disruptions. Brief enough to affect some electronics, especially if the AC was drawing heavily to keep the compressor going while voltage dropped.

ETA: The above assumes it wasn’t ghosts, the most likely reason for all such odd phenomena.

For me, it was the wired smoke detector going bad at 3am in the morning. The one that was about thirty feet up in our vaulted ceiling, and we didn’t have a ladder that could reach it at the time.

I had to go buy a really tall ladder first thing in the morning just so I could shut the damn thing off. Just because it’s a wired smoke detector doesn’t mean that it’ll last forever- ours were only about five years old, but all started to go bad about the same time despite being on the house wiring. The truly annoying thing about them is that the beeps are only about once every thirty seconds, and damn near impossible to locate.

I’ve started replacing all of our smoke detectors with Nest smoke detectors, because those will clearly tell me which ones are having issues. I’ll never use standard detectors again.

My dishwasher will beep when the door has been closed, but the “resume” button not pressed if in the middle of a cycle.

You said “we”, so I assume more than one person heard the same thing. If that is the royal “we”, could it have been in your head? I sometimes wake when I hear a phone or doorbell ring (once), and I’m pretty sure it didn’t, but was a mental, dream, construction.

Yeah, this (except fortunately for me I don’t have vaulted ceilings). Three beeps means the alarm itself is going bad and needs to be replaced. Why they always go bad at 2am is a question for the ages.

My generous thought is so you’re home to hear it. If it beeped during the day, everyone might be at work. My less than generous thought is that they’re sadistic bastards.

I started a thread on a BEEP a while ago. It was the Verizon FIOS battery. I didn’t know the FIOS had a battery until then. BEEEEEEP.

Came to mention the same Verizon FIOS battery.

It drove me nuts until I found it. A quick order on Amazon and I had a new battery to swap in.

Yeah, both of us. Nothing royal about me other than being a PITA.

No UPS equipment.

I’d have thought power interruption except as noted above.

The smoke detectors don’t beep, they chirp loudly and only once per episode.

I’m going to go with ADT doing some weird shit in the middle of the night. I know that they do ping your system from time to time to see if it’s functional, but have never heard beeping before.