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Andrew Gabriel

In article ,
writes:
Hello All,
I have a mains powered - with 10-year lithium backup - interlinked
fire alarm system comprising of 3 off Optical Smoke alarms and 1 off
Heat alarm (for the kitchen)
I changed the 2 Ionisation alarms to optical on the advice of Kidde -
about 3 years ago after sporadic alarms occurred (usually in the early
hours of the morning) when there was no cooking/ironing/smoking or
anything triggering them. At this time the units were all about 3
years old. Kidde did not accept the units were faulty in any way but
did replace FOC.

Now, here I am a further 3 years on and one of the 'new' optical
alarms has started the same game. I have been able to determine which
unit is at fault (this time the alarm continues for a period of 20 to
90 seconds giving time to run around and see which one has triggered)
and have removed and disabled this unit. NB There have been no false
alarms during this 3 year period from toasting/cooking/ or from the
mysterious cause until 2 weeks ago and then had 3 alarms in this last
2 weeks

Does anyone else have this problem?

I had a Kidde optical battery alarm go off at 4am.
There was no one there at the time, but no sign of any fire
on returning, and none of the other 3 alarms (all ionising)
detected anything. It stopped after 35 seconds.

Although they are bog standard battery alarms, they are
actually all linked back to an alarm panel, so I have a
precise record of what happened. Never found the cause though.
It was about 6 weeks after testing them all with smoke detector
test spray (which reminds me, I haven't done that for over a
year now).

Should I expect the unit to need replacing at 3 yearly intervals? Each
alarm costs around £40 so this gets a fairly expensive hobby (OK, I
know its not much compared to saving your life but.....)

No.

Expected life is normally about 10 years, and that's mostly
about limiting dust build up in parts you can't clean. In a
more dusty location, maybe you should change more often.

--
Andrew Gabriel
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