Baffling puzzle for electrical experts

WatlingA5

Really weird... Was vacuuming on first floor (yes, I know it's Christmas Day, but needs must!) and as the Henry cleaner head (set up for carpets) passed over the metal doorstrip (brass-effect aluminium I think) the smoke alarm in the hallway below went off - just four beeps.

We worked out that the alarm is almost immediately below the strip. We experimented and switched off and unplugged the vac (a Henry) and passed the vac head over the area again... the mains-powered alarm went off, just a couple of beeps while the head was over the strip. The depth of the carpet means it's unlikely the metal carpet-sweep section actually touched the metal.

Next, we removed the head from the vac altogether and, just pushing the head back and forth by hand, moved it over the strip. Alarm sounded again; not every time and sometimes only after two or three sweeps.

Only thing we can think of is that the carpet (material unknown as it came with the house) is building up static between the metal of the cleaner head, the carpet and the brass strip, which somehow makes the alarm go off.

We definitely haven't smelled any smoke and this is not the day to call our friendly electrician (we want to keep him friendly!) so any info here would be most welcome.

In the meantime, enjoy your Christmas :beer:

Neil

ic

Is the smoke alarm hardwired? Sounds like a screw or nail for the metal strip has perhaps pushed against the wire - push the strip and it makes contact...

spannerzone

Probably the huge amount of static that a vacuum cleaner can create and if nylon content in the carpet it could exaggerate the problem. Nothing really to worry about if no smoke/flames

muckybutt

I'm inclined to say it is static build up in the local area from the vac use that's causing it.

WatlingA5

A belated thankyou for the helpful advice. We're not going to worry any more

TiddlyPom

Bet it kept you entertained for hours though!

WatlingA5

Was going to leave it at that smiley but forum insists on more words... :snow_grin

Happy new year!

WatlingA5

Just when you thought this one had gone away...

We had some work done recently which involved an electrician. We asked him about it and he too had never heard of it. But he pointed out the smoke alarm was a very old design and asked when it had been replaced. We bought the house (built in 1997) only last year so we had no idea.

He took the alarm down and pointed to the label which indicated it should have been replaced in 2007. So it seems it was the original and some eight years overdue .

We now have a new smoke alarm. We've still no idea what caused the beeping but the problem has gone away