I have had a mains Parkside BMH 1100 SDS drill for a few years, its
been 100% reliable, soon after getting it (after the instruction were
lost) a red LED lit up leaving me guessing as to what it was for..

It has a usefull green LED for when it has power, then a red one. The
red one has rectangular solid line box symbol, followed by a second
rectangular box symbol made up of dots. It is double insulated and uses
a two core flex, but the symbol next to the red LED is not a double
insulated symbol. Anyone know what the red LED indicates, it comes on
as soon as power is applied to the drill?