I've got hard-wired smoke alarms in my house, installed by my building
contractor when the house was built four years ago. For reasons I'm not
certain of, there are two different type/brand alarms in place.
The alarms have started beeping, presumably because the back-up batteries
need changing. Problems, however:
1. Two of the alarms (of the same type/brand) beep three times in
succession, a couple of times a day. But I can't get them off the ceiling!
I've tried everything I've ever known or could learn about smoke alarms to
get them to unlatch, so I could change the batteries, but to no avail.
There is no marking anywhere I can find on the outside of the alarm to give
me either instruction for opening or even the brand name. I've twisted,
turned, pried, and prodded them and cannot get them loose from the ceiling
without pulling down the drywall.
2. Another of the alarms (different type/brand) comes off the ceiling
easily using standard techniques. However, as it turns out, this one
doesn't need to come off the ceiling for battery changes, as the battery
compartment opens from the accessible bottom/down side. I changed the
battery with ease. Several times. It won't stop giving me the weak-battery
warning, no matter how carefully or how many times I replace the battery.
If there's something I'm doing wrong, short of replacing the whole alarm,
I'd like to know what it is.
I've put pictures of both type alarms (from various angles) on the following
binary newsgroups on Usenet, under the same subject line as this message:
alt.binaries.pictures.misc and free.binaries.misc. The beige-ish photos are
of the alarm in example number 2 above, and the grey-ish photos are of the
unremovable alarms in example number 1 above. Can anyone identify these
(especially the grey-ish photos) or tell me how they are supposed to be
opened or removed from the ceiling? And can anyone suggest why changing the
batteries in the alarm in the beige-ish photos doesn't stop the beeping?
(And yes, I'm certain of the polarity. It's clearly marked on the alarm.)
Most smoke alarms contain tiny amounts of
radioactive elements that sooner or later stop
functioning as designed -- which may cause the
beep signal, to prompt you to replace the unit.
A single mains-connected smoke alarm in our
house died about seven years after installation.
We replaced it by a battery-powered unit since
power outages were then common where we live.
I not sure I can help you with getting the ones off the ceiling but I
have had a go around with nonstop beeping ones.
I run into this before with the FireX Smoke/CO detectors.
As it turns out when changing the batteries you need to also unplug
the unit from the back or kill the circuit breaker supplying it while
the battery is out and leave it off for about one minute.
This allows it to reset.
Hope that helps.
2 different types are required here in MA. Ones that go within 20' of
bath or kitchen, ionic I think they are called. Bedrooms and other living
areas that are not within that 20' get another kind, photo-electric.
On the standard "pro" contrator grade ones for both types there is this
little small plastic pin that goes in to the base, right at the ceiling
level. This pin stops the detector from twisting which is how you remove it.
Pull the pin, twist a bit, should drop down with your wires attached. Change
the battery and put them back up.
buffalo ny: when in doubt, throw it out, applies to all my safety
devices. unless they have changed it again, you will be throwing out
your CO detectors every five years. you will be replacing your smoke
detectors [with a frequently updated newer model number] as the old
ones fail or under the latest recommendation under wikipedia research
at 10 years.
also read thoroughly the manufacturer's fine print. remember dust and
humidity and spiders are the natural enemies of these smoke
also, candle fires start 20,000 fires a year is a statistic i had not
read in awhile. [we didn't allow them for our kids when they were
growing up. and they are not permitted in our rental apartments, since
it led to a tenant's candle by the window curtain bedroom apartment
fire in 1974 in a house i later bought.]
i started at:
and follow the bottom links including:
here is just one page quoted:
"NFPA urges replacing home smoke alarms after 10 years
Quincy, MA, October 23, 2001-Replacing batteries in home smoke alarms
will be a common ritual this weekend for many people as daylight
savings time ends. But if smoke alarms in your home are more than 10
years old, NFPA (National Fire Protection Association) recommends
replacing them, as well.
Why? According to NFPA, aging smoke alarms don't operate as
efficiently and often are the source for nuisance alarms. Older smoke
alarms are estimated to have a 30% probability of failure within the
first 10 years. Newer smoke alarms do better, but should be replaced
after 10 years. Unless you know that the smoke alarms are new,
replacing them when moving into a new residence is also recommended by
Smoke alarms, when properly installed, give an early audible warning
needed to safely escape from fire. That's critical because 85% of all
fire deaths occur in the home, and the majority occur at night when
most people are sleeping. Last year, NFPA documented 3,420 home fire
Fully 94% of U.S. homes had at least one smoke alarm as of 1997,
according to NFPA, but as of 1998, 40% of the home fires reported to
U.S. fire departments and 52% of home fire deaths still occurred in
the small share of homes with no smoke alarms. Half of the deaths from
fires in homes equipped with smoke alarms resulted from fires in which
the smoke alarm did not sound--usually when batteries were dead,
disconnected or missing.
"Simple steps like maintaining smoke alarms and replacing older ones
help diminish the possibility of fire deaths in the home," says John
R. Hall, Jr., NFPA's assistant vice president for fire analysis and
research. "Smoke alarms in the home are largely responsible for the
decreasing number of home fire deaths over the last decades."
NFPA offers the following smoke alarm safety tips:
* Install new batteries in all alarms once a year or when the
alarm chirps to warn that the battery is dying.
* Test units at least monthly. Test the units using the test
button or an approved smoke substitute.
* Clean the units, in accordance with the manufacturers'
* Do not use an open-flame device for testing because of the
danger the flame poses.
* Smoke alarms should be placed outside each sleeping area and on
each level of the home, including the basement.
* In new homes, smoke alarms are required in all sleeping rooms,
according to the National Fire Alarm Code.
* Alarms should be mounted on the wall 4-12 inches from the
ceiling; ceiling-mounted alarms should be positioned 4 inches away
from the nearest wall. On a vaulted ceiling, be sure to mount the
alarm at the highest point of the ceiling.
As electronic devices, alarms are subject to random failures. Product,
installation, and maintenance standards are used to assure products
work as designed despite this. Part of the technical basis for the
first alarm product standard was an assessment of expected failure
rate, estimated at four per million hours of operation or one every 30
years. Early field studies of alarm reliability, notably by Canada's
Ontario Housing Corporation, confirmed the essential accuracy of this
estimate, restated as a 3% failure rate per year. This means a very
small fraction of home smoke alarms will fail almost immediately, and
3% will fail by the end of the first year. After 30 years, nearly all
the alarms will have failed, most years earlier.
How soon should you replace your alarm? This is a value judgment. Only
3% of alarms are likely to fail in the first year, and annual
replacement would be very expensive, so that doesn't make sense. At 15
years, the chances are better than 50/50 that your alarm has failed,
and that seems too big a risk to take. Manufacturers' warranties for
the early alarms typically ran out in 3-5 years. So, in ten years
there is roughly a 30% probability of failure before replacement. This
seemed to balance safety and cost in a way that made sense to the
responsible technical committees.
If a 30% failure probability still seems too high, remember that
replacement on a schedule is only a backup for replacement based on
testing. A national study found home smoke alarms, when they fail,
tend to fail totally, as opposed to hard-to-detect creeping failure,
such as a loss of sensitivity.1 Regular monthly testing will help
discover alarm failure as well as a dead or missing battery. You can
replace your alarm when it needs replacing.
The same study showed all the inoperable alarms tested in 1992 were at
least 5 years old and predated a 1987 change in product standards that
reduced sensitivity to reduce nuisance alarms. Changes in alarm chip
design, among other improvements, make it likely that electronic
failure now occurs at a rate much less than 4 times per million hours
Replacing alarms after 10 years protects against the accumulated
chance of failure, but monthly testing is still your first, best means
of making sure alarms work. Today's alarms are even less vulnerable
than the original alarms. Regular maintenance of the more
sophisticated systems used in larger buildings can keep them working
very reliably for many decades.
1 Julie I. Shapiro, Smoke Detector Operability Survey, Washington:
U.S. Consumer Product Safety Commission, October 1994 revised.
NFPA (National Fire Protection Association)
1 Batterymarch Park, Quincy, MA 02169-7471 USA
Telephone: +1 617 770-3000 Fax: +1 617 770-0700 "
1. Push, then twist.
2. What's it look like on the other side of the drywall ceiling?
3. Perhaps the alarms are reflecting the condition of the CENTRAL battery?
You said they were hard-wired, maybe there's a large, universal, battery
I found the solution to the one where I changed the battery but the beeping
wouldn't stop. I took the battery out, disconnected the wiring from the
ceiling, and was about to heave it out the window when the beeping
continued, despite the fact that there was now no power of any kind
available to the alarm. But when I carried the alarm outside the room, the
beeping stayed inside. The solution to my problem arose when I discovered a
C02 alarm plugged into the wall behind the bed. I changed ITS battery and
the beeping stopped.
Two weeks I've lived with that beeping. Some days I suspect I may NOT be
smarter than everybody else.
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