Why is my electric smoke detector chirping?

It’s completely wired in the wall, and there’s no battery compartment. You can’t take it out- if you try, it will go crazy. If I can’t change the battery, why is it chirping every couple of minutes?
P.S. Please answer before I have to go to sleep tonight.

There is a battery compartment, you just have to find it. Even ones plugged into a wall, meaning installed with the house have back-up battery compartments. Have a 9-volt handy, you’ll need it. Rest easy tonight.

p.s. is it circular? If so you’ll have to turn it counter clockwise [i think] and then when you see the wire going into the wall, unplug it by grasping both sides and pulling. You’ll see what I mean when you get it out.

Ah… ok. Thanks Phlosphr, I did it!
Note to self: Just because your 14-year-old is almost 6 feet tall does not mean he is capable of everything about the house. No battery compartment my butt.

If the detector is more than 5 years old, it might be unable to detect smoke quickly enough. Get a new one. They wear out, or something. You might grumble about the cost, but wait. Look in the eyes of your family. Now, is forty bucks too much?

You don’t have to believe me; ask a fire fighter.

Not all of them. My house has hardwired smoke detectors, and no battery backup in any of them.

I recently replaced all of them (3, 1 on each floor) for about $15 each. Though they claimed they were direct replacement, they did require me to remove the old mounting plate, and install a new one.

Mine too have no battery compartment.

In the interest of a good nights sleep, if you have more than one change them all.

I have 6 or 7 smoke detectors and if one goes a couple of the others almost certainly will within a very short time period. And in the middle of the night.

Ain’t this the truth? The one right outside our bedroom door started chirping right as we were trying to fall asleep (actually, my wife was trying - I had been asleep since the McKinley administration). After she woke me up, I was able to find the 9-volt, bleerily climb on a bar stool (dangerous), and replace the battery. About 3 days later, it started again - only this one was outside my daughter’s bedroom.

I went to the hardware store and bought enough to replace them all at the same time.

Actually, the NFPA applies a ten year lifespan to smoke detectors. When members of my department install detectors for homeowners, we write the install date on the back of the detector with a Sharpie. The other option is to purchase detectors with a 10 year lithium cell, and when they go bad, your ten year replacement plan is right there.

A note to Dopers who need to replace a hard-wired detector: make sure that the replacement you’ve purchased is compatible with the existing. Putting in an incompatible unit will not only result in failure to operate, it can damage the others. I recently had a customer try to save a few bucks and do it himself- I ended up replacing all 12 detectors in the four bedroom, mini-mansion.

As others mentioned, the detector could be out of calibration from being too dusty or the sensor drifting from being too old.

If it’s a photoelectric detector, some are made such that the baffle can be removed and the dust blown out. That would be a more expensive, hard-wired detector ordinarily.