I have recently moved to a new house and the existing electric shower
has a pipe that appears to have some sort of overflow pipe coming from
the power box. This now has water coming through it and connects to
nothing so has caused a leak in the ceiling. However I have directed
it to an over flow pipe so that for the mean time it pours outside if
the shower is in use. I could direct it into the main hot water tank,
but is this OK to do so? Is it mean't to have water coming out
everytime the shower is in use? Is there a proper way to deal with the
water other than the above.

The shower is a Triton T200RE that has a flush fitting control panel
and a separate power box fitted within the roof space.