Black and Decker BDS303 3-in-1 Finder

Hoping someone may be able to guide me in the use of this tool. I have just purchased this and the instructions seem somewhat contradicted by the results I am having.

I want to use this tool to defect electrical wires. According to the instructions this detection is automatically turned on for all settings and the LED should flash when a wire is found. However, my one beeps when I go near a socket but does not flash. When I move the detector in a straight line upwards it continuously beeps but does not flash. On other walls all it does is flash red as if the wall is covered in wires!

If anyone out there has one of these perhaps you can give me some much needed guidance.

Thanks.

Do you have foil backed plasterboards on your walls if so that could be your problem.

I thought that but there are walls where it doesnt flash red indicating no wires. The issue I have really is the fact that it beeps where I know there are wires rather than flashing an LED. Perhaps if someone who owns one can enlighten me?