Beeping fire alarm. Should I be alarmed?

January 16, 2009 6:02 AM

Beeping fire alarm. Should I be alarmed?

Last night, my fire/smoke alarm started emitting high pitched beeps. Thought it was beeping because of low battery--ones in the old house did this. But when I took the cap off, remembered that it's the kind that's directly wired in.
So, what does it mean that it's beeping? It beeped couple of times last night, then couple of times again this morning. I've triggered the alarm by accident in the past while cooking, so I know what it sounds like when the alarm is full-on on, and this isn't it. It's just a signal beep.
Other information that possibly be related. Not sure if it's just a smoke detector or a smoke and carbon monoxide detector. It's been unusually cold here, so the gas furnace has been on constantly.
If it turns out it's broken and needs to be replaced, do I need an electrician, or where can I find directions for doing it on my own.
Thanks. As you can tell from the somewhat ramble, I'm at a loss here, so any suggestion/insight would be welcome.

posted by jujube to home & garden (20 answers total)

even hard wired ones have batterys
posted by patnok at 6:10 AM on January 16, 2009

Are you renting or do you own it? When we rented, we had wired-in detectors that still had some battery backup. It beeped for a day before we realized we should call someone...maintenance fixed it for us.
posted by cobaltnine at 6:11 AM on January 16, 2009

Yep, my hard wired ones have batteries and make the random beepy noise when the battery is low.
posted by thejanna at 6:11 AM on January 16, 2009

Hardwired smoke detectors usually have battery backups. Also, I had a carbon monoxide detector that beeped because some sort of cartridge/filter needed replacing.

Nothing to worry about. Replace the battery.
posted by bondcliff at 6:12 AM on January 16, 2009

There's almost certainly a battery somewhere--otherwise you could die in an inferno if the power goes out.
posted by adjockey at 6:22 AM on January 16, 2009

If you have a gas furnace and you're not sure if its a carbon monoxide detector or not, it might be worth stopping by Lowes or somewhere similar on the way home and picking up a C02 detector anyway. You can get detectors that plug into an outlet so it can go in any convenient spot in your home.
posted by 543DoublePlay at 6:27 AM on January 16, 2009

I'm dying to contribute to this thread, but all I can do is confirm that hard-wired detectors usually have a battery, too.
posted by These Premises Are Alarmed at 6:31 AM on January 16, 2009 [1 favorite]

Might be the battery, but maybe not -- both CO2 and Smoke detectors will beep when it's time to replace them. They do go bad! This will be a different beep than the low battery beep. They're cheap insurance, and the (unlikely, but not completely so) alternative of burning to death in a fire means it's worth it to swap out your detectors every 3-5 years. I think the life expectancy of a smoke detector is 10 years, but given the cost, why not buy yourself a little more insurance? Swap 'em out. It's $70 or less for a six-pack of detectors at the local home improvement center.
posted by Geckwoistmeinauto at 6:33 AM on January 16, 2009

I got curious and did some googling; looks like it takes a 9 volt (transistor) battery.

Premises, that was eponysterical.
posted by theora55 at 6:35 AM on January 16, 2009

Thanks everyone re: battery suggestion. When I took the top off last night though, I didn't see a battery. It was just electric wires coming out of the unit, connected to the electric wires coming out of the ceiling. Should I have taken the detector unit itself apart? I was afraid of trying to take it apart, because it didn't look like it was built so that it could be taken apart without breaking it.
Also, not a rental, so I would like to be able to do this on my own without having to call/pay for an electrician to come out.
Thanks.
posted by jujube at 6:48 AM on January 16, 2009

If your willing to spend the money, I'd shut off the power, remove the thing and cap the wires, and replace it with a battery powered one. Then also put a carbon monoxide detector near the furnace. But that's just me, but I'm still alive.
posted by hungrysquirrels at 7:03 AM on January 16, 2009

If your willing to spend the money, I'd shut off the power, remove the thing and cap the wires, and replace it with a battery powered one.

Seem like bad advice to me. Hard wired with redundant battery back up is better than just battery. nthing that hard wired smoke alarms have battery backups. Suggesting that jujube just did not see it.
posted by fixedgear at 7:11 AM on January 16, 2009

Dust will also do it sometimes. I've had it happen twice with older wired in alarms. Both times the only way to get it to shut up was to completely disconnect it and then dismantle it and, perhaps coincidentally, perhaps because I'm cursed, both times it happened at about 3:30 in the morning. One of them kept beeping even after it was disconnected from the house wiring and the backup battery was removed; I finally had to pitch it out the window into the woods. Yet the house was not on fire, either time. I know this because I walked around sniffing like a beagle for about two hours after the beeping incidents. Finally someone - maybe here, actually? - told me it was dust screwing up the sensors.

Toss it and go get a couple of new alarms. They're not super expensive and you can install them yourself.
posted by mygothlaundry at 7:41 AM on January 16, 2009

This happened to me once with a CO detector. It was beeping once every 2 minutes or so. We were able to look up the manual online by using the product number on the detector (maybe you can do this as well?). Turns out, the beep frequency was indicative of the problem--for example, if it beeps once every 5 minutes it needs a new battery. In our case, beeping once every 2 minutes (or whavever it was) meant that the sensor had gone bad. Basically, the whole thing just needed to be replaced. Not really the most satisfying answer, but it could explain why it's beeping without a battery.
posted by Jemstar at 8:04 AM on January 16, 2009

The battery compartment is often on the side of the unit, look for a drawer or door on the sides.
posted by kbibb at 8:12 AM on January 16, 2009 [1 favorite]

This might sound weird, but make sure it's actually coming from where you think it is -- we had this issue a few years ago and I swore it was coming from one particular smoke detector, we changed the battery and it kept beeping, then later on we found that it was the CO detector down the hall -- there was something about the sound itself or the acoustics that made it sound like it was coming from another place.
posted by mattholomew at 8:59 AM on January 16, 2009

Do take alarms seriously.
posted by Carol Anne at 9:47 AM on January 16, 2009

I had two hardwired detectors in my house that over the years had the wiring become loose and so would run mainly on the backup battery, emitting beeps as is usual when the battery died. When I repainted the hallways in my house I also replaced them both; it was very easy and now I know I have fully functional units. This article suggests that smoke alarms should be replaced every ten years, so you might want to take that into consideration as well.
posted by TedW at 12:26 PM on January 16, 2009

Those detectors don't last forever, and they're cheap and easy to replace. They come with pretty simple directions and you don't need an electrician to do the work. They're about as complicated as replacing an outlet. Even easier if it has a wiring harness, which would be a plastic connector between the device and the house wiring. Don't take a chance on a faulty detector not working as it should.
posted by orme at 9:06 PM on January 16, 2009

If your willing to spend the money, I'd shut off the power, remove the thing and cap the wires, and replace it with a battery powered one.
--
Seem like bad advice to me. Hard wired with redundant battery back up is better than just battery. nthing that hard wired smoke alarms have battery backups.

The suggestion comes from moving around a lot in rental units. Pretty much every hard-wired smoke detector I've seen has been bashed, sometimes dangerously with regards to loose wires, by people trying to get the thing to shut up. Whereas when only battery powered, if you burn your toast, simply remove the battery until the air clears and put it back in.

There's usually reminders in the media twice a year at the daylight saving time change to replace the battery in your smoke detectors. Don't ignore it, and you're fine. Better than a hard-wired one that doesn't work because it's been bashed.

Mods, sorry for the chatfilter. Delete if irrelevant to the question at hand.
posted by hungrysquirrels at 10:19 PM on January 16, 2009