beeping smoke alarm at nite--why is this?

[Jean S. Barto]

Hi folks--

I have a smoke alarm in my house that beeps at night, in the middle of the night. When this starts, it beeps about 8 or 10 times, then stops, and then starts doing this again about 5 to 10 minutes later. It started doing this

2 nights ago. Both nights I ended up cutting off the power into my house so I could get a good night's sleep.

This only happens at night, and does not happen during the day.

I opened up the smoke alarm this morning, and found that it is the kind that is wired directly into the house wiring--it does not have a separate battery of any kind, nor a place for one that I can see.

Could power spikes/fluctuations in the middle of the night cause the smoke alarm to go off? That's the only thing I can think of.

Lastly, my house is still standing, and I don't smell any burning in my house. The smoke alarm is located on the second floor of my house, in the hallway, opposite my master bedroom--so it is far away from anything in the house that could have any residual *burning* smell, such as the oven/stove in my kitchen.

Thanks in advance for your help. Hopefully I won't have to cut the power into my house every nite to keep this from happening in the future.

Jean in VA

[m Ransley]

Maybe a dirt on the sensor and a change in humidity at night, try blowing or vacume it clean.

Battery backup? maybe its low cycle is coincindently at night .

Defective unit , cause ?

A dead relative trying to contact you and keep you from sleeping, or warn you.

Having a battery only back up is always good measure.

[John W. Wells]

Opposite your bedroom, you say?

Surely you've heard this old saw:

He: "Do you smoke after sex?" She: "Dunno--I never looked."

;-)

Well, if it starts beeping annoyingly during the day, your method will sure certainly your electrical bill!

Seriously (and knowing nothing about such technology), if there's no battery that could be run down, I'd just replace the alarm.

And lastly, it's a rare day that I find someone on Usenet that knows when and how to use a dash--I think I love you! :-)

~John W. Wells

[SQLit]

Try cleaning it with canned air, like what they use to blow out computers. Do not use isopropyl alcohol on the sensor, isopropyl has water in it. An dry Q-tip would work, pretend it is your eye, gently. In higher humidity times the eye can get fooled. What does your a/c filter look like? Floaties in the air might cause this. Then again it could be broken and time for an new one.

[John Grabowski]

Smoke detectors are only good for ten years. If it is old replace it. If not, try cleaning as others have suggested. If that doesn't work replace it.

John Grabowski

[Joseph Meehan]

My guess is the battery is going. It is usually cooler at night and the battery is putting out just a little less power and that is triggering the low battery beeps.

[xrongor]

what battery?

randy

[Charles Spitzer]

some systems have a wet or gel cell battery in another place that powers alarms in case the power goes out.

[Jean S. Barto]

Like I mentioned in my first post, I can't see a battery of any kind in the unit anywhere--I think it is wired directly into the wiring in the wall. If there *is* a battery in it, I can't see it.

I wasn't aware that smoke alarms *wear out* and need to be replaced periodically. I thought only the batteries (if it has one) required replacing.

Thanks again,

Jean in VA

[Joseph Meehan]

Most if not all do have a battery, even when they are connected to the main.

It would seem they do. In any case if it is really old, I would recommend replacing it anyway. The newer ones are better. BTW if it does not have a battery backup, then replacing it would give you a chance to replace it with one that does have a battery backup. Fires often accompany a power loss.

[Colbyt]

Jean,

If you only have the one unit and there is no battery compartment visible at the BACK of the unit then yours does not have a battery back-up, is most likely ready for replacement and you should consider replacing with a battery back-up style unit. Of course the replacing can be done with no help IF you can find the exact same unit. You would just unplug the old and plug in the new.

The symptoms you describe are typical for a unit that has a weak battery and replacing all the batteries at the same time typically solves the problem. It is also typical for a unit that has experienced a dust build-up and the compressed air clean out may work.

I have never seen the unit described by another poster which has a remote battery. My experience is mostly with the Firex brand. There unit has 3 wires. White, black and yellow to allow the multiple units to be inter-connected. I would think that a remote battery unit would need at least two more low voltage wires to power the back-up feature.

Colbyt

[George E. Cawthon]

Could be a lot of things. If you know the type, it can help. Also, consider what is different at night. As an example, the alarm installed in my house at construction over 28 years ago is the light at an angle type. In normal conditions, the light never gets to the sensor since it can't travel around a corner. Smoke will cause the light to disperse and some of it is reflected to the sensor. Unfortunately, tiny spiders ocassionaly find a home and construct webs which can blow and deflect the light to the sensor. That's one possibility, and if so, you can clean the passages, or just really blow the heck out of it with a vacuum. A burned out lamp will also cause a noise but it won't be just at night. A failing lamp may also set it off. Lots of other possibilities. The simplest solution is to replace it with a battery operated unit.

[Ron Hardin]

If you sleep with the windows open, a temperature inversion can keep small amounts of smoke near the ground, and it drifts in and the smoke detector detects smoke even though you don't.

Get one with a snooze alarm.

[Retiredff]

'Wear out' might not be the correct term, but they do lose their effectivness. I'm not sure how long ago (hasn't been long), a 10-year life span was placed on smoke detectors. It is recommended that they be replaced at that time.

Several years ago, manufactures started making low voltage-type detectors. If yours is more then a few years old, then you can not just buy a replacement and plug it in (provided the plugs are the same. There is no standardization). If you do, you will burn up the new one.

Your best bet would to look at yours and find the manufactures name, then find out what they have that is compatable. I do know that FireX makes a direct replacement for there older units. And, to be on the safe side, please get one that has a battery back-up, and use a 10-year battery in it.

Larry (also in VA)

[indago]

040812 1750 - George E. Cawthon posted:

Everybody is in the house sleeping at night, exhaling carbon dioxide fumes and setting off the sensitive alarm system.

[MrAoD]

I wouldn't advise that. Cutting the circuit, yeah, but not the whole house. Or perhaps I misunderstand?

At least 7 years old IMO. Virginia code went from battery to hardwire to hardwire with a backup battery about 7 years ago.

Smoke detector sensors do go bad.

Battery compartment's pretty obvious so I'm guessing your house is between 10 and 20 years old?

You only got one smoke alarm? Code calls for one per floor, and hardwired systems are usually interconnected - if one goes off in the basement and you're upstairs sawing wood the upstairs one is suppose to echo.

If you have more than one alarm check the others - they might have battery backups, but I doubt that's it.

Dude, she said no battery in the thing. 9V hookup is kind of hard to miss.

I'm guessing the unit's bad (or one of the units if there is more than one and interconnected)

We rented a beach house in Hatteras, 3 levels, from the top level down the alarms were 1, 2, and 2. We had the same problem, double-tap beep, nothing for about 3 minutes, then another double-tap, lather rinse repeat. I wound up pulling the power leads to the beeper (they were snap-in connections) and called the realty company the next day.

Jean, just go ahead replace the units if you don't find a bad battery somewhere in the (hypothetical) others. They're old and only semi-reliable, the sensors go bad over time. If that doesn't fix it call an electrician or a handyman if you know a good one.

Can't be too safe.

Marc, who changes the batteries every equinox.

[JerryMouse]

Smoke detectors use a teeny bit of radioactive material (Americium) to ionize the air flowing over a sensor. Americium decays over time an becomes less energetic. The half-life of Americium-241 is approximately 430 years, so, if your house is about that old....

[George Wenzel]

Given how cheap they are to buy, it makes sense to replace smoke detectors periodically (every 10 years is the usual recommendation) - especially if the existing one is getting wonky.

Regards,

George Wenzel

[George E. Cawthon]

Yeah but! Smoke alarms don't detect carbon dioxide.

[George E. Cawthon]

Not all smoke detectors. My 120V model uses a light in a small passageway. Smoke entering the system reflects the light to a sensor. There really is nothing except the bulb to wear out.