How to Fit a Ball Valve in Your Cold Water Tank

To start, turn off the water at the mains.

Wear protective gloves, knee pads, goggles and a dust mask as fibreglass insulation can cause respiratory and skin irritation. You should also avoid disturbing the insulation as much as possible. Lay an MDF board (or similar) over your attic insulation so you can kneel down comfortably beside the cold water tank. Using an adjustable wrench, unscrew the feed pipe instantor fitting.

Pull the copper pipe away from the ball valve housing.

Undo the retaining nut outside the water tank and remove the ball valve by pulling the valve body from the water tank.

Insert the new ball valve assembly, checking to make sure that the ball is securely attached. Pass the threaded valve housing assembly through the hole in the water tank and tighten into place with the retaining nut.

Push the copper pipe, complete with its olive (the soft brass ring at the end of the pipe), into the valve body and tighten the instantor fitting firmly but carefully. It may be necessary to change the olive if it shows signs of damage. Dry the fitting thoroughly.

Turn the water back on again at the mains, and check the new joint for any leaks by holding a dry cloth directly underneath the newly tightened fitting. If the joint is tight and there is still some water escaping, you have a damaged or deformed olive and you will need to replace it.