Looking for Advice

[PennyC]

Not sure if this appropriate, but I'm looking for some informed advice about problems I'm having with my smoke detectors. While doing house renovations, I had new ones put in (5 in total) hard wired with battery back up. I though I'd done the sensible thing. In the last two years these have set off for no reason three times - as you may imagine the noise is impossible, and loud enough to annoy my neighbours as well. The only effective way to stop it is to take out the electric circuit with the circuit breaker, then remove each one in turn from the ceilings (which my arthritis and fear of heights means I can't do myself, but no-one would find this a fun task at 3am anyway), and remove the batteries until the row stops. Firstly does anyone have any idea why this is happening? And is there any solution to the problem other than removing all the batteries and then using the circuit breaker as a switch until I can get an electrician in to replace whichever one has malfunctioned?  My electrician has not been able to come up with any other solution either.

Thanks in advance

PennyC

[Keith]

Penny firstly no problem in asking for advice and despite the problems you're having you certainly did the right thing in fitting the detectors you've described.

I'm probably only going to tell you something your electrician will have already told you though, that the most likely cause is a faulty detector which occasionally you will get and yes it generally happens at the most inconvenient time. Other possibilities are the backup battery going flat and rather than chirping as should normally happen, it sets the system off, a build up of dust or insects getting into the detectors. Giving the detectors a vacuum out form time to time and changing the batteries once a year may help.

[Carefree]

What I'd have said, dust/insects can and do set these off.  Get into the habit of sticking the vacuum pipe around the vents from time to time.

[Carl]

As mentioned above, you clearly have a faulty detector which if inter-connected will set them all off. Firstly you need to find out which detector it is which would only be achieved by taking it out of the system and seeing if the fault occurred. The problem is, by the time you have diagnosed this, your electrician is likely to have sorted it. 

Im no electrician, but he may have a quicker way to identify a faulty detector.

Im afraid there is no quick fix. I would be tempted as a temporary measure to replace a suspect detector with a battery one rather than take it completely out of the system and have none at all in that particular area.

[Messyshaw]

Could it be the positioning of the detectors. 5 detectors does seem quite a lot and I am intrigued to know where they are located and who installed them?.

The standard that domestic smoke detectors are installed to (especially hard wired units) is British standard 5839-6 2013. When it comes to locating the detectors there are 3 x levels of protection offered:

LD1 is detectors pretty much everywhere

LD2 is detectors in circulation spaces (hallways and stairs) plus high risk areas 

LD3 is just in circulation spaces

More info here.

I have a three storey house and have hard wired detection on each landing - three units in total - as in LD3 as above. I have a solid door on my kitchen which I close at night and generally (except on boiling hot nights) all bedroom and living room doors onto the staircase are closed. I am happy with that set up for my family

A friend has a three story townhouse with an integral garage taking up all of the ground floor. The door from the garage to his downstairs hallway and only escape route is solid but is not a fire door. He has a car, motorcycle and all sorts of rubbish he stored there. I suggested a LD2 with smoke detection in the garage as well as the circulation space

LD1 is generally used (but not exclusively)  in HMOs - houses converted into multiple bedsits and similar high risk environments

Lastly, if you have smoke detectors in or near your kitchen, you might want to reconsider. Heat detectors of domestic use are available in kitchens, and its always best practice to site smoke detection away from kitchens or bathrooms

Good luck

[PennyC]

Many thanks for the advice. Just for info I have one in the kitchen (on the basis that this is the likeliest place for a fire) one in the hallway ground floor, one on the first floor landing, one in my bedroom, and one in the office over my garage, which is far enough away from the rest that a fire would not be quickly detected. I've now had this happen three times (the system is less than 2 years installed, and the first time was within a year). One time the fault was in my bedroom, and one time in the hallway downstairs, the third occasion I am not sure. The house is professionally cleaned every week, so although I can't rule out dust (I can rule out the backup battery going down, at least the most recent time, as they were all working), efforts are certainly made to avoid it. I have to admit, however, that i've never in my life been a good closer of doors, nor do I think I am likely to be...

 

A fault is annoying, but if I could switch it off and get an electrician out I'd put up with that - but there is no way to get anyone out at 2am or at lunchtime on a saturday. I can't climb a ladder myself, and the house is uninhabitable, even with earplugs in, with them all going off. I need some system that will allow me to switch them off once I have checked that nothing is actually amiss. They are on a single circuit, so the circuit breaker does cut mains power to them - but the batteries allow them to go on for days. I know removing the back up batteries is not an ideal solution, but neither is having my hearing damaged by having to put up with the noise for many hours

[Cashybai]

I'm surprised that one is fitted in the kitchen, unless it's a rate of heat rather than a smoke detector, purely because cooking smoke will set them off time & time again. The kitchen is indeed a likely place for fire to start, but it can be eclipsed by other housekeeping factors such as overloaded sockets, dodgy phone chargers or the current white goods saga. With regards to how the faults were identified previously, can you confirm how it was determined which head was defective? Only to rule that out, Its a difficult one, as hardwired domestics don't necessarily come with a panel to allow a remote reset. Could you use an extending pole or similar to push the offending alarm reset/silence button?

[PennyC]

The only way we could identify the offending one was to flip the circuit breaker then remove them in turn. The offending one continues to howl on its internal battery, but the others don't. And although I poked at everything available with my walking stick (there seems only to be one button in the middle of it, and I think that is a test one) this had no effect at all. Nor did the poking of anything reachable from the top of a ladder by a kindly neighbour. Oddly, the only time i set off the kitchen one was genuine smoke from having forgotten to switch on the extractor fan, and it turned itself off once I did that and opened the door. The house is newly rewired ( so no overloaded sockets), and all the appliances are new. (< 2 years) One failed, but is now completely disconnected. The only charger I use is for recharging batteries, and that hence is used relatively infrequently.