how can i stop overflow running continuous from attic water tank?

Carl is right turn mains off [or tank feed off if it's got it's own stopcock.] remove the end cap of the ball valve barell housing, but left out the following bit. You have to remove the split pin holding the ball arm in the valve housing before you can remove the valve barrellpull arm forwards slightly to pull barell out a bit. then drop the arm free of the barell slot and pul out the barell. Although it's difficult to see the washer end about 1/4 inch unscrews to reveal the full washer. The easiest is to take the barrell to the plumbing shop and get a replacement but get the plumbing shop to fit a new washer in the old barell just in case the new barell doesn't fit.

bob
August 2005

It sounds like the valve has had enough. Turn the water off at the incomming supply. If the ball-cock assembly is the old brass type with a screw cap on the end facing the ball, take the cap off and remove the bits noting the order. Take these bits to the local plumber or DIY store and smile nicely! Failling this, remove the whole assembly and take it to the shop. You will need two pairs of adjustable spanners and some white plumbers tape (PTFE) for re-assembly. Go-on, you can do it.

Carl
July 2005