Ball Valve Problems

If a cistern overfills and water runs from the overflow pipe, the inlet valve is not closing early enough and the water is rising higher than the intended level. A metal or plastic ball floating on the water is connected to a lever that works and controls the valve. If the rubber washer, which fits on to the valve, is worn, it will allow too much water to enter the cistern.

Remove the cover of the cistern. Flush the cistern, holding up the ball arm. If this completely stops water coming in, the washer is not worn enough to need replacing. Instead, adjust the valve by bending the ball arm. Be careful neither to strain the valve mechanism nor to damage the ball itself. It is possible to hold the bar in two hands and bend between them very gently. Allow the cistern to fill. Check that the water is reaching the marked level before the valve shuts off. If there is no marked level, water should come to within about 25 mm (1 in) of the bottom of the overflow pipe.

If holding up the ball arm does not completely shut off the water — even allowing just a very slight drip — bending the arm will not stop overflowing and the washer will have to be replaced. Turn off the water supply if possible, although it is possible to do the repair while water continues to flow, but you have to flush every time the cistern fills.

The ball arm pivots on a cotter pin (split pin). If its ends are spread, pinch them together, then pull the pin out with pliers from the other side. It may be possible to use the pin again, but if it is buckled and worn, use a new brass or stainless steel one. Pulling out the pin allows the arm to be removed, but before doing this, use its extending top to push out the piston that carries the washer, so its end can be gripped.

At the end of the brass piston the washer can be seen as a little pad enclosed by the metal. The metal joint may not be obvious, but the end with its hole is screwed to the main part. Unscrew this cap with pliers, but put cloth in the jaws so they will not mark the brass. Fit a new washer and re-assemble the parts. See that there are no waste parts of the old washer left in place. Use a cloth on a rod to wipe where the washer is attached to the nozzle. If the valve parts are dull and corroded, clean them with fine emery paper and metal polish, and apply a little petroleum jelly to the piston casing.

Put the parts back together and allow the cistern to fill. Check the water level when the valve closes. With a new washer it will probably not be high enough. Flush the cistern and bend the ball arm up slightly, then try again until the correct level is reached.

If you have a high cistern above a lavatory pan, do not stand on the lavatory seat nor on a board across the earthenware pan. The weight of an adult could break or crack the lavatory frame.

Ball valves are also used for controlling the inlets to water tanks, If water runs from the overflow pipe of a roof tank, it can be repaired in the way described for a cistern. Some ‘silent’ cisterns have the water controlled in a different way. If removing the top of a cistern shows a system very different from that described its repair is better left to a plumber.


It is important that water does not seep between the edges of a bath, shower or basin and the wall, where it could cause rotting. In the past, sealing was done with plaster and other materials that eventually became brittle and fell out. If this edge sealing has to be replaced, pick out all the old material and clean off the surfaces. Make sure they are dry and free from soap and grease.

The best sealant now is a silicone rubber preparation, available in colours to match basins and tiles, and supplied in a tube with an applicator nozzle, which can be cut to the width needed. Hold the tube at an angle and squeeze while pushing (not pulling), always following the manufacturer’s instructions. Smooth within five minutes and leave for 24 hours. Excess sealant can be wiped off with a tissue or cut away when it is dry.


If a lavatory seat and its cover are loose, examine the fixing screws and nuts at the back. The nuts underneath may be a wing type for hand tightening. There should be soft washers above and below with screws fitting through loosely into their holes. This is deliberate so as not to risk damaging the glazed earthenware pan. If washers have disintegrated, they should be replaced. Tap washers can be used.

In some installations the lower washers are conical to go into the holes and prevent excessive movement of the seat. Turn the wing nuts only hand tight. If there is a tendency to work loose after a short time, put spring locking washers under the nuts.

When sealing a sink or bath, use a rubber-based sealant which will remain elastic.

Although most seat units are similar sizes, if you do decide to fit a new one, measure the sizes of the holes in the pan and their distance apart, when you go to buy a new unit.

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