On Apr 10, 2:44 pm, "DD" someone@somewhere wrote:
I checked the earth wire and found it had unwound itself from the mains
downpipe...Uhhhh!

Earthing wire must not be wrapped around anything. That wrapping is
bad for same reasons why sharp wire bends compromises protection.
Essential that an earthing wire from every protector be short ('less
than 10 feet'), direct, separated from other non-earthing wires, no
splices, etc. Each earthing connection should be separate until all
meet at the single point earth ground at the service entrance. A
water pipe ground is typically too far away; therefore insufficient.
A short and direct connection to one dedicated earthing electrode or a
common connection to an earthing 'system' defines protection.

BTW, above discussions were only about secondary protection. That
secondary protection 'system' is defined by its central and essential
component - the earthing electrode. Your primary protection system is
also defined by the one component that defines that 'system' and also
should be inspected:
http://www.tvtower.com/fpl.html