The Overflow

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May 28, 2014
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The design of the overflow is quite simple, it is a normally redundant pipe that is fitted to a water storage system and will only come to life should the water level in the storage vessel rise above a pre-set safe level. Therefore the sight of water gushing from an outside overflow pipe could be quite serious. Now the reason for this could be that a valve that controls the water inlet of the appliance has jammed open or just failed completely. The controls for this type of inlet normally take the form of something called a float-operated, (or ball) valve. A Finsbury Plumber can replace faulty valves or pipework.

Potential Causes for Failure:
1). A faulty or worn washer can be one of the reasons for the failure. The washer could be heavily worn or have perished due to constant. There could be a large build up of scale around the area of the seal causing the sealing action of the washer to fail.

2). Ball floats can be subject leaks, filling with water. The water inside will affect the buoyancy action and stop the level but is very rare. If this occurs, then, buy a new float. Finsbury Plumbers are professional plumbers who can repair all pluming issues.

Replace a Defective Inlet Valve:

1). Firstly you will need to isolate your water supply. If you have a storage cistern, you can lower the water level by using the toilet flush or even opening the taps. When the cistern is dry you can then remove the old valve.

2). The usual way that this is done is by unscrewing the large union nut in the cistern, this will normally release the valve for servicing and inspection. The part that remains holds the valve in the cistern and onto which the water supply is connected. Simply undo the nut on the new valve. Re-fit the replacement valve. Which is quite straightforward. When you are finished you can adjust the water level as required.

The water level is usually marked ‘water level’ on the inside of the WC cistern. For a cold-water storage cistern it is usually 25mm below the overflow pipe connection

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