Mains Smoke Alarm queries

Det Somerset

Hello, apologies in advance as these queries are probably quite vague or paranoid but I'd appreciate it if someone could point me in the right direction.

My bungalow was renovated last December and three mains connected smoke alarms were installed in the kitchen, hallway and living room. Two weeks ago my wife swept up a lot of dust in the hallway and the living room and later that night we accidentally left a candle burning in the living room and were awoken by the smoke alarms going off in the living room and hallway. They sounded for about 30 seconds before stopping. We blew out the candle thinking it was the cause but the same thing happened again at regular intervals for the rest of the night (maybe 4 or 5 times in total)

After researching the next day it seemed like it was possible it wasn't the candle and instead dust from the cleaning that took place earlier that day which seemed to make sense. I took both alarms down and opened them and didn't find any significant dust and one of them appeared to be a heat alarm only which wouldn't explain how dust could set it off (and it was in the hall while the candle was in the living room)

Then one of the alarms started going off again at (shorter 5 sec) intervals during the night after being quiet for over a week. This time we can't think of anything that would have set it off? That was two nights ago and last night was quiet. So my first query is do I have faulty alarms or is there some other possible explanation here?

My second question is could the alarms possibly be linked in a way other than radiolink? (ie via the mains?) I'm pretty sure they aren't radiolink as they look standard models but the facts that two went off simultaneously and when I had one disconnected the other chirped a bit, it just seems a bit weird. It is probably coincidence but the kitchen alarm (which otherwise has not gone off) has started chirping on occasion which I presume means the battery is low. But as the battery was changed in December I'm wondering if the noise is indicating something else?

All advice and opinions welcomed. TIA

mikeyjames9

the 9V radiolink alarms have a 'radiolink' sticker on the outside of alarm and a red 'house code' button inside the alarm


you would know if smoke alarms are interconnected by pressing and holding the 'test' button


mains alarms will have a green power indicator




too late but alarms should be covered obviously if there's work involving dust

Det Somerset

Thanks a lot MikeyJames9

In that case, deffo not radiolink but they are connected as the test rings on all three. I presume the connection is in the wiring?

Literally as I was typing, they have gone off again for about 10 seconds. I can't think of anything that could be causing it unless we have one dodgy alarm that is setting all three off.

My wife just swept the floors that time. It wasn't like there were clouds of dust or anything. Would that suggest it wasn't the dust causing it, and further suggest a dodgy unit?

meercat

Get the vacum cleaner at them with a skinny nozzle
Failing that replace the batteries

mikeyjames9

yes try the above

if replacing batteries use 'duracell ultra'


didn't spot where you said mains alarms and renovation
they're probably standard mains alarms with a wired interconnect(seeing as it's a bungalow) anyhow

EI do a mains radiolink setup too but it's unlikely you have it

looksee

We also have a 'paranoid' issue with mains alarms, but have not been able to produce the effect to order in the presence of an electrician. Randomly when a light switch is pressed, the alarm goes off for two beeps, never any more or less. One switch in particular has been doing this since the alarms were installed, but gradually, and very slowly, other switches seem to be picking up on it. It would happen maybe a couple of times a day, unless you want it to! Would love to be able to sort it.

Det Somerset

mikeyjames9 wrote: »

yes try the above

if replacing batteries use 'duracell ultra'


didn't spot where you said mains alarms and renovation
they're probably standard mains alarms with a wired interconnect(seeing as it's a bungalow) anyhow

Ok, now that I know they are linked, my layman's theory is that it's all related to the kitchen alarm which needs it's battery replaced. That theory fits because the low battery chirping and random alarms all started around the same time (within 24 hrs). Because we haven't changed the battery it's probably also sounding off on occasion which is setting the others off at the same time. My problem is the kitchen alarm was installed at the top of a vaulted ceiling and we have no way of reaching it safely. I'll have to hire someone to get up to it. My intention is to actually disconnect it from the mains and remove the battery before replacing it for cosmetic purposes before installing a standard battery alarm in a more accessible place in the kitchen.

In the meantime I've disconnected the other two from the mains so they are now just operating off battery. I guess if one of the alarms goes off again soon we'll know which one has the problem, but my money is on the kitchen one at the moment.

Thanks for all the advice guys. Probably basic information for you but it's cleared up a lot of confusion for me already.

Bpmull

Surly it's not the best idea to disconnect the two working smoke alarms as the battery's only last so long on them. If you end up leaving it a few weeks or forget about fixing the kitchen one. Then you will effectively have no working smoke alarms in the house. They are there for a reason. Also if you position a new smoke alarm low down in the kitchen it will probably go off when cooking hence why the other one is probably placed high so I'd personally just change the battery in the one that's their . A mains interconnected system is always going to be better than the battery ones. Just my views on it I'm not an Electricien or anything I just don't think disconnecting fire alarms is the best idea.

mikeyjames9

Bpmull wrote: »

Surly it's not the best idea to disconnect the two working smoke alarms as the battery's only last so long on them. If you end up leaving it a few weeks or forget about fixing the kitchen one. Then you will effectively have no working smoke alarms in the house. They are there for a reason. Also if you position a new smoke alarm low down in the kitchen it will probably go off when cooking hence why the other one is probably placed high so I'd personally just change the battery in the one that's their . A mains interconnected system is always going to be better than the battery ones. Just my views on it I'm not an Electricien or anything I just don't think disconnecting fire alarms is the best idea.

yes indeed ,i can't quite follow what the OP is at but he seems to be going about things the wrong way


probably creating problems that didn't exist in the first place

mikeyjames9

looksee wrote: »

We also have a 'paranoid' issue with mains alarms, but have not been able to produce the effect to order in the presence of an electrician. Randomly when a light switch is pressed, the alarm goes off for two beeps, never any more or less. One switch in particular has been doing this since the alarms were installed, but gradually, and very slowly, other switches seem to be picking up on it. It would happen maybe a couple of times a day, unless you want it to! Would love to be able to sort it.

check the switch that's causing the issue anyhow..tighten connections

are the alarms on an independent circuit (separate mcb) or a branch off the lighting circuit?

Det Somerset

Bpmull wrote: »

Surly it's not the best idea to disconnect the two working smoke alarms as the battery's only last so long on them. If you end up leaving it a few weeks or forget about fixing the kitchen one. Then you will effectively have no working smoke alarms in the house. They are there for a reason. Also if you position a new smoke alarm low down in the kitchen it will probably go off when cooking hence why the other one is probably placed high so I'd personally just change the battery in the one that's their . A mains interconnected system is always going to be better than the battery ones. Just my views on it I'm not an Electricien or anything I just don't think disconnecting fire alarms is the best idea.

I appreciate your opinion but I think you probably haven't understood what I'm trying to do.

Firstly our kitchen is huge and the new smoke alarm position won't be close to the cooking area or even that low. It will just be somewhat accessible by a standard ladder for when it needs to be reached. Currently it is impossible to reach and I can't be hiring someone every time the battery needs to be changed (This is the second time in a year) and the constant beeping is a serious annoyance.

Secondly while I appreciate your concerns about ending up with no smoke alarms, we need to sleep and having the alarm just outside our bedroom going off repeatedly in the night is something I had to put a stop to. In addition, this method may help determine which of the alarms is going off in the first place.

I have already been in contact with someone who is going to disable the kitchen alarm next week and as soon as that's done the others will be reconnected to the mains with new batteries inserted. It's possible even now you would still prefer to do things your own way, but this method suits me for the next few days.

Det Somerset

mikeyjames9 wrote: »

yes indeed ,i can't quite follow what the OP is at but he seems to be going about things the wrong way


probably creating problems that didn't exist in the first place

Have tried to explain the situation better to bpmull above, but if you still think it's the wrong approach, I would have to respectfully disagree.

ronan45

How does one test a smoke alarms smoke sensor as opposed to the test button that just tests the back up battery
and also which of these is a mains powered smoke alarm I need to replace mine as they are about 12 years old
http://www.woodiesdiy.com/action/searchsite/smoke%20alarm

mikeyjames9

ronan45 wrote: »

How does one test a smoke alarms smoke sensor as opposed to the test button that just tests the back up battery
and also which of these is a mains powered smoke alarm I need to replace mine as they are about 12 years old
http://www.woodiesdiy.com/action/searchsite/smoke%20alarm

canned smoke
http://ie.rs-online.com/web/p/fire-alarm-detector-test-kits/4945991/

go to the electrical wholesalers and they will give you the proper alarms

Bruthal

Det Somerset wrote: »

Have tried to explain the situation better to bpmull above, but if you still think it's the wrong approach, I would have to respectfully disagree.

You may disagree with a posters opinion that you are possibly creating more problems. But there's hardly much argument against simply replacing all batteries first, as opposed to altering the detector circuit as a means of testing theories, based on the fact you have difficulty reaching one detector to replace its battery.

Det Somerset

Bruthal wrote: »

You may disagree with a posters opinion that you are possibly creating more problems. But there's hardly much argument against simply replacing all batteries first, as opposed to altering the detector circuit as a means of testing theories, based on the fact you have difficulty reaching one detector to replace its battery.

I expect I'm showing my ignorance here, but I don't understand your point. As I couldn't reach one alarm I couldn't change all batteries 'first' unless I was willing to put up with continued sleep disruption. Neither my wife or I were prepared to do that so I had to take a different approach. In my mind, the only way to identify which one definitively was 'faulty' was to disconnect them from the mains so that the next time it went off, it was the only one doing so. I knew this would happen within a few days so it wasn't like I was disconnecting them and going to forget about it.

As it turns out, one of the disconnected (heat sensor) alarms started going off yesterday evening for no reason, so that appears to be the faulty one. I've now replaced the battery but left it off the mains until it proves reliable (a week should do it), the other one is back on the mains with new battery, and there is someone coming tomorrow to decommission the kitchen alarm and I'm fitting a new more accessible one at the weekend. Seems like that will be the end of it unless I have to replace the 'faulty' one, but at least I have identified it now.

Thanks again to those who helped explain the workings of the smoke alarms to me here. I may not have taken your preferred path to resolution but my own path would have been far more difficult to find without your advice.