D
Doggit
You just take the fuse out of the fused spur feeding the panel, the bell will go off (so warn the neighbors first) you then remove the 2 screws on the front, and remove the red lead to the battery. Then you just reverse the procedure. Now if you're feeling brave, you can change the battery whilst you've got the panel open - it's a 12v 2.3AH battery.
If it works, then you've have saved yourself the cost of the engineer, and you can feel chuffed with yourself.
If it works, then you've have saved yourself the cost of the engineer, and you can feel chuffed with yourself.