i have to change a transformer on one of the spotlights in my kitchen but when i turn the power off at the mains fuse board my house alarm goes off. I have done this in the past (as recently as 3 months ago) and the house alarm has never gone off before. when the alrm goes off the remote keypad bleeps when i enter the numbers of mycode but will not switch off. i have to turn the mains power back on before it will accept my code and switch the alarm off. When the alarm switches off the tamper light shows up. Any ideas what the problem is please and is there an easy fix to resolve it or do i need to get a professional out? Thanks in advance.

Mike., October 2009

Good morning my alarm went off when l turned my electric off, l tried a new battery still didn,t work, then l noticed there is 4 clear 4 amp fusses so l checked them and one had blown causing the alarm to go off when l turned my electric off or when l had a power cut, put a new new fuss in happy days all sorted

Andy Fisher, March 2011

I have the same problem when the mains is turned off the alarm is triggered, i have changed the battery and when iturn the mains off the same happens, it appears that there is a problem with the panel taking power from the battery, is there a fuse i need to change.

KK, July 2010

try a new battery this is a must the idea being when the mains power is turned of the battery takes over and no alarm (makes sense )

Mike T, November 2009

Hi Mike- answer is that I am here writing this! Never done it before- so just pulled the battery out a bit and pulled the connectors off- they are plastic coated - if you don't trust that just pull them off by the wire- it's no problem and at worse- even if you did it might be a 12v battery tingle- not a 240v mains belt. The beauty is that you don't need to turn the mains off so the alarm won't trip and annoy the neighbours.

jimmyfed, October 2009

thanks jimmyfed, may sound a stupid question but do i need to turn the power off while i remove the old battery an replace it with a new one? i don't wan tot get a belt from the mains.

mike, October 2009

Mike- just cured the same problem. What happens is that the internal alarm battery drains down- mine did after a power cut- when you turn the mains off the alarm senses that there is no battery power and sounds off as it thinks it is a tamper attack. Solution-new 12v 2.1ah rechargeable battery- about £8.00 from an electrical supplier or £28.00 from Maplin. You change by removing front cover from alarm panel- if it triggers enter your alarm code to stop it. Next just pull off the red and black spade connectors from the battery-you can go shopping for a new one. The alarm won't go off - it's just a back up battery. Simply reattatch the spade connectors and replace the front. Job done for 8 quid.

jimmyfed, October 2009

Hi acorn thanks for the quick response. Is it an easy task to change the battery over? Also as i assume the mains power has to be off to change the battery so the alarm will be going off, any idea how long it should take to change the battery over?

mike, October 2009

You need a new battery

acorn, October 2009