MTBF simply means mean time between failures. What are they saying?
the MTBF is 10 years? So what, do you throw away everything that goes
past the MTBF?
Anyway, my 120V unit is just fine at 28 years old. The only failure
part is likely to be the light bulb (1st one failed at about 15 years)
and the light detector which hasn't failed yet. Reguards.
No, but given that smoke detectors are safety devices, it's prudent to
replace them periodically, to minimize the chance of them not working
when they're required.
That may be, but the chances of a 28-year old smoke detector failing to
work properly in a fire are greater than the chances of a new detector
failing. Smoke detectors are the cheapest form of life insurance.
George Wenzel, B.A. (Criminology)
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.
George Wenzel, B.A. (Criminology)
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
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.
And if she builds a new house, that will be pertinent.
If indeed, it was taken down and out and inspected and not checked while
twisting it and standing tippy toe on a chair.
Mine are hardwired. When they beeped (ALWAYS at 3AM), I learned
that there WAS a battery. But I had to pull the wire off first.
At 3AM, I moved to the guest room and let it beep. Figured out
the wiring when I could focus my eyes.
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.
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.
I am real irritable when something or someone wakes me up. That thing
would have been tossed out on the lawn the first night, if not
smashed. Unless there is a dead backup battery, Replace it and get a
good nights sleep.
<SNIP story about it being an AC-powered rather than battery-powered,
I had this a few months ago (not night-specific but beeping only at
times), and after a week or two found another smoke detector with a
battery in it lying around somewhere and that was the culprit.
If you know for sure that you have zeroed in on the right detector, then
replace it - especially if it is more than 10 years old. (Detectors
showing no signs of anything wrong are usually good for 20 years, but I
have heard that they are not perfectly-as-good-as-new after 10.)
- Don Klipstein ( firstname.lastname@example.org)
The problem is that you don't know if they are losing their effectiveness or
not. It might look brand-new after 20 years, but when that time comes and it
is 'needed', it may not work. That is why there is now a recommended 10-year
life span on them. Don't risk it.
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