Alarm help??

Hellrazer

Looking for a small bit of help with a very annoying home alarm problem.

Every night I set the alarm and it sets fine according to the control panel.

Between 5.00 am and 5.15 am exactly every morning for the last week and a half the alarm has gone off indicating a trigger in "zone a" which is the upstairs windows in the house.

Im pulling my hair out with this one--theres no one awake at that time,no sign of any tampering with the windows(considering its the second floor windows--I doubt that theres someone trying to break in)

Has anyone got any ideas???
Im leaning towards a faulty window sensor but how do I troubleshoot something like that--theres 6 sensors it could be.

Thanks

Richie.

bertie1

Are you sure it isn't a bird at the window . I had it about the same time every morning at one stage , what every way the sun was shining on the window , it caught birds attention & they started pecking at it , they have gone since

fishdog

Can you split downstairs into 2 zones (front and back) to narrow down wher the problem is?? Keep narrownig it down until you are at just one window. If you could do this then at least you would know the exact location of the problem. Perhaps then you could use a different type of protection on that window.

Is there a mains circuit that switches on at this time (such as boiler) that may be inducing a current into the alam cable for that zone??

fred funk }{

Chances are its a faulty sensor. You'll need a multimeter to test them. Nearly all faults with alarms are down to bad connections somewhere, be it inside the sensors where the gold plate wears off the sensor head and corrosion sets in (most likely) or a damaged cable somewhere.
Sometimes when an alarm false alarms roughly at the same time it can be down to the 'bad connection' expanding and contracting as the house heats up and cools down. The Sun could be shining at a certain part of your house at that time thus heating up the 'bad connection' and expanding it.
If you have wooden windows these can 'crack' with the heating up-cooling down of the house too and that will set off the alarm but you would notice that not long after the alarm or windows first went in.

Hellrazer

fred funk }{ wrote: »

Chances are its a faulty sensor. You'll need a multimeter to test them. Nearly all faults with alarms are down to bad connections somewhere, be it inside the sensors where the gold plate wears off the sensor head and corrosion sets in (most likely) or a damaged cable somewhere.
Sometimes when an alarm false alarms roughly at the same time it can be down to the 'bad connection' expanding and contracting as the house heats up and cools down. The Sun could be shining at a certain part of your house at that time thus heating up the 'bad connection' and expanding it.
If you have wooden windows these can 'crack' with the heating up-cooling down of the house too and that will set off the alarm but you would notice that not long after the alarm or windows first went in.

I think myself that its a faulty sensor alright.Last night when I went to set it I was getting an open circuit in the same zone (upstairs windows)
After about an hour or so when the house was cooler it set normally but didnt go off this morning at its usual time

fred funk }{

Get yourself a cheap multimeter, Maplins used to sell them for a tenner. Post back when you do and i'll tell you how to test the sensors.

Hellrazer

fred funk }{ wrote: »

Get yourself a cheap multimeter, Maplins used to sell them for a tenner. Post back when you do and i'll tell you how to test the sensors.

Multimeters at the ready.
Noticed that on each window sensor theres 4 wires feeding each--I take it that its 2 for the "vibration" sensing parts and 2 for the "magnetic" part?

I was going to by pass them one by one over the next few days and see which one eliminates the problem-and then replace the faulty one.

fred funk }{

Hellrazer wrote: »

Multimeters at the ready.
Noticed that on each window sensor theres 4 wires feeding each--I take it that its 2 for the "vibration" sensing parts and 2 for the "magnetic" part?

Yes, that correct.
Depending on the type of sensor some have two wires from the sensor block and are pushed into another small terminal black block and some are wired directly on the head.

You will need to figure out which is for the sensor.
Put your multimeter on 200 ohms. Then push the two prongs from the meter onto the screws holding in the cables. You should get a low reading, about 1 ohm. Tap tap sensor gently and you'll see the reading change, it should then settle back to the same reading as before, do this about ten times with each sensor. If the reading does not return to the original reading you have a faulty one.
Faulty sensors should stay up by at least a few ohms. Even if you find a faulty one make sure you test them all because you could well have more than one.
And when buying your sensors get the very same type because it will make it much easier to change them.

Clear as mud

fred funk }{

How did you get on?

cd76

Hi,

I think I have a similar issue to hellrazer. My alarm has been going off at different times but each time its the same zone.

Should I try the same process with a multimeter. Or could it be buses going by and causing the viration. Has worked Ok for 8 years so I doubt its traffic. If I have to replace a vibration sensor where can I buy them.

thanks a lot

Hellrazer

@Fred Funk.

I owe you a few pints.I meant to post the results earlier!!!You were bang on.There was one sensor where the ohms were settling at 8-10 ohms after tapping it a few times--it was the one in the upstairs bathroom so I reckon there was maybe water getting into it since it looked corroded after I opened it up.I replaced it and havent had one false alarm since.

Once again thanks for the help.

Richie.

fred funk }{

Hellrazer wrote: »

@Fred Funk.

I owe you a few pints.I meant to post the results earlier!!!You were bang on.There was one sensor where the ohms were settling at 8-10 ohms after tapping it a few times--it was the one in the upstairs bathroom so I reckon there was maybe water getting into it since it looked corroded after I opened it up.I replaced it and havent had one false alarm since.

Once again thanks for the help.

Richie.

No probs, glad you found it because it can get interesting when the meter doesn't find anything