To do any work on the water system in your house, you will need to empty the pipework first. You may not need may to empty the complete system, but at least the required section will need to be drained. Croydon Plumbers are experienced professionals.Locate and label stopcocks and valves.So that you are familiar with the various and important valves in your home, it would be as well to identify and familiarise yourself with the location and job of all the valves and stopcocks in your house. This will allow you to rapidly isolate them if required. Draining cold water.You can isolate the taps that get their supply from the mains directly with the stopcock on the riser. You can then open some the taps to drain the excess water.Draining the tank in the loft.Indirectly supplied items are serviced by water from the cistern in the attic. The water from this may be stopped by closing the valve from the cistern to the section you are concerned with. Alternatively, supply from the cistern can be stopped totally. To do this, place a length of wood over the tank and tie the ball valve up to it in the closed position. The tank can now be emptied by opening all the cold taps supplied from it. A Croydon Plumber is trained to carry out this type of work.Switching off the rising main.The same result is achieved by turning off the rising main and opening all the cold taps. This removes the necessity to tie up the ball valve but has the downside of also cutting off supply to the direct fed parts of the system as well.