Draining the cold Water Storage Tank and Hot Water Cylinder

To drain the storage tank in the roof space, close the main stopcock on the rising main, and open all the taps in the bathroom. Bail out the residue of water at the bottom of the tank. South West London Plumbers can drain all systems for maintenance or repair.


Draining the hot water cylinder:

If the hot water cylinder springs a leak (or you wish to replace it), first turn off the immersion heater and boiler, and shut off the cold feed to the cylinder from the storage tank (or drain the cold water storage tank). Run hot water from the taps.


Locate a drain cock from which you can drain the water that remains in the cylinder. It is probably located near the base of the cylinder, where the cold feed from the storage tank enters. Attach a hose and run it to drain or sink that is lower than the cylinder. Turn the square headed spindle of the drain cock till you hear water flowing. A South West London Plumber is trained to work on all water storage systems.
Water can’t be drained if the washer is baked onto the draincock seating, so disconnect the vent pipe and insert a hosepipe to siphon the cylinder.


Should you want to replace the hot water cylinder, don’t disconnect its pipework until you have drained the cylinder completely. If the water is heated indirectly by a heat exchanger, there will be a coil of pipework inside the hot water cylinder that is full of water. This coil can be drained by the stopcock on the boiler after you have shut off the mains supply to the small feed and expansion tank in the roof space.