just a quick one. Uncle has the above alarm in his house been in for 5 years or so and all has been working fine until he set it off the other day. apart from going off at the keypad none of the other sounders triggered. Going to have a look at it this weekend but was thinking that the bell fuse could of blown? Would you agree? Also will replace the battery as that's going to be on its way out now - could a flat battery blow the fuse?