If you still can't use your alarm after you have replaced the battery try this.
disconnect the mains power and the battery,
leave the power off for a few seconds
then reconnect ,your alarm should come back to life again.
enter your code to switch it off and press reset.
if your code doesn't work try the factory code 0123
( if you have to use this code then your alarm will need to be reprogrammed)
john from stoke, May 2006