Mains powered Smoke Alarms

[sleeper341]

Hi, I have installed 4 linked Mains powered smoke alarms in my house and they have been fine until yesterday. They have started letting out an intermittant 'beep' about every 55 seconds. I called the manafacturer who told me they had no idea why they would do this and suggested i cleaned them. I've done this yet they are still 'beeping'. Has anyone any idea why they might have started doing this?
The only thing i can think of is that I a few days ago I painted my ceilings up stairs (cheap white emulsion) and perhaps the fumes are causing this to happen although the smell of paint isn't that strong.

please help, its like chinese water torture 'beep............beep'!

 

[JonB]

Has it got a duff backup battery?

JonB

 

[sleeper341]

I don't think the battery back up is duff, I disconnected them and they still beep even without mains power which suggests to me the batteries are ok.

 

[andrew5235]

That probably means that the battery backup is duff as when the batteries get low they chirp every minute or so. This means that you get a reminder to change the battery before they run out completely.

Andrew

 

[sleeper341]

Thanks, I'll take one apart and see if they can be replaced. I think the units are sealed though, and there is no mention of the back up batteries in the instructions. You'd have thought the manafacturer would have told me that when i spoke to them!!

 

[felix]

The backup battery is normally a PP3 (standard 9 volt battery available in every street market on the planet) and you would see it when you fitted the alarms. Perhaps yours don't have battery backup.

Intermittent beeping is something ours do after you press the "silence" button. The idea is that you press this to shut the things up after a false alarm but they beep afterwards to remind you that they've been silenced. They stop beeping when the cause of the false alarm (usually steam from our kitchen) goes away.

 

[sleeper341]

I definately can't see a pp9, but as i said earlier they do beep even when disconnected from the mains so there must be some battery backup. I've had all my upstairs windows open today (i'm bloody freezing now) and they seemed to have shut up, so I guess my theory about the paint fumes might be correct. Thanks for your help guys.

 

[breezer]

i will still favour battery back up, as has been said you removed the mains and it still beeped, that is a battery, it may have gone flat by now which is why it has stopped.

i had to check a similar situation to yours, no battery says everyone, took down detector, after2mins really looking what do i find ? pp3 battery sort of oblong ish, but also flat

 

[JonB]

I "Googled" Smoke alarms and some have a rechargable Lithium battery fitted.

JonB

 

[sleeper341]

Ok checked inside and can't see a battery anywhere. I checked the product on Srewfix (where i bought them) and they are not fitted with a battery back up (there is a version that is, but not what i bought being a cheap skate!).

http://www.screwfix.com/app/sfd/cat/pro.jsp?id=10476&ts=14938

So i have no idea whats causing the beep except the possibility of the paint fumes. Its driving me nuts. I might call out the fire brigade to inspect them.

Do you think it matters that i haven't actually attached them to the ceiling yet (they are just hanging at the mo)?[/url]

 

[kendor]

interesting reading on ionisation detectors aswell as optical:
http://www.angliacampus.com/education/fire/secondar/smokedet.htm

 

[breezer]

I might call out the fire brigade to inspect them.

please tell me that is an atempt at humour

 

[ninebob]

please tell me that is an atempt at humour

Why not? The fire brigade have long been advocates (obviously) of smoke alarms, so I'm sure if they were able to get this person's set-up working properly, they would (and should) do so.

Something doesn't ring true here though. Sleeper has isolated the alarms from the mains and they still beep, yet he is convinced there is no battery backup.

To put simply:

1. Disconnected from mains
2. No backup DC power
3. A beeping noise

At least one of the above conditions MUST be false.

 

[breezer]

please tell me that is an atempt at humour

Why not? The fire brigade have long been advocates (obviously) of smoke alarms, so I'm sure if they were able to get this person's set-up working properly, they would (and should) do so.

Because they put out fires, rescue people etc, give advice. They are NOT the makers of any smoke alarm, electrciains, fire engineers.

That would be like asking your local CPO to fix your burglar alarm

In other words is nothing to do with them what smoke alarm you have and or if it works. first port of call is as you suggested or send it back.



I still say its got a battery, maybe a battery one was sent instead?

CPO being crime prevention officer

 

[sleeper341]

apparently the fire brigade will send out an inspector to test smoke alarms if you ask - they won't send the whole fire engine though, just a man in a car.

one of the 4 detectors (first on the chain) doesn't beep at all 2 of them seem to beep alternately every minute (middle 2) or so and one beeps more infrequently (last on the chain). its all very strange, i'm going to swap some of them about and see if they still beep in the same order - at least that will tell me if its the actual alarm at fault or if it is to do with where they are located.