cancel
Showing results for 
Search instead for 
Did you mean: 

House Alarm

Community Veteran
Posts: 7,923
Thanks: 599
Fixes: 8
Registered: 02-08-2007

House Alarm

The other day when a new electricity meter was fitted the house alarm went off when the supply was reconnected and the guy said this was due to the battery, which needed changing.
Anyone know anything about house alarms ?
If we ever have a power cut (not uncommon around here) several house alarms go off but in our case the alarm goes off when the power goes back on, so do I need a new battery (which are not exactly cheap)
5 REPLIES
oldgeezer
Grafter
Posts: 206
Registered: 02-02-2010

Re: House Alarm

Most house alarms use two batteries,  a small 12 volt sealed lead acid in the control box (usually about 2 A/h), and a little 7.2/8.4  volt ni-cad battery in the alarm box outside on the wall. If the alarm goes off during a power cut it's probably the battery in the internal control box. They last about 5 years on average.
They cost around £10/15 trade but make sure that you get one of the right physical size and rating. When you remove the box front the anti-tamper alarm will sound but you should be able to cancel that with the keypad. Just isolate the mains supply before you remove the cover and observe polarity when connecting the battery. If you're not sure get an electrician to do it for you.
oldgeezer.
Community Veteran
Posts: 14,469
Registered: 30-07-2007

Re: House Alarm

One other reason for replacing the battery after 5 years is the fact that if it has actually failed, it can get hot and potentially become a fire hazard. Try placing your hand on the main control box where the batter is and see if it feels hot. If it does it could be the battery.
Note: most house alarm systems have a maintenance code which you need to enter after setting off the tamper in the control box to stop the alarm sounding - sometimes the normal set code does not do this.
Community Veteran
Posts: 6,735
Thanks: 12
Registered: 02-02-2008

Re: House Alarm

Quote from: gleneagles
1.The other day when a new electricity meter was fitted the house alarm went off when the supply was reconnected and the guy said this was due to the battery, which needed changing.
2.Anyone know anything about house alarms ?
3.If we ever have a power cut (not uncommon around here) several house alarms go off


OK...
2. Yes
1. It could be, but there are other reasons, it needs investigating.
3. That's because they've not been maintained and probably need new batteries
I'd get someone competent/professional to service your alarm, assuming it's not been done for several years. That would probably include a new battery in the control unit AND in the external bell.
Community Veteran
Posts: 7,923
Thanks: 599
Fixes: 8
Registered: 02-08-2007

Re: House Alarm

Thanks for the info. It has been over 5 years since the last battery change so will replace it myself.
There is a fuse in line with the alarm but I will play it safe and switch the main power supply off.
The main CPC depot is only a few miles away so can check the actual battery number in their catalogue before buying  another one.
Community Veteran
Posts: 5,322
Thanks: 467
Fixes: 1
Registered: 21-03-2011

Re: House Alarm

Keep your lead acid battery cool. It seriously shortens their life if they live in a hot place.
Now Zen, but a +Net residue.