Water Overflowing

[Dunstable Dasher]

Most mornings I find the overflow pipe coming out of the roof from the attic running with water (not the one from the toilet cistern) if I run off some hot water it stops, can anyone tell me why it does this and how do i remedy the problem ?

 

[Lee-King]

Change the ballvalve

 

[BoxBasher]

It runs in the morning because it has the opportuniy to fill up during the night and overflow.

As lee-King says, check the ball-valve and replace if required.