Identifying services

2, Water

Before you start doing any plumbing work you should identify the appropriate stopcocks to cut off that particular part of your water system.

There are two basic domestic water systems – indirect and direct..
The traditional water system is the indirect system. Cold water is supplied from the mains to the kitchen tap and to a storage tank in the loft which feeds the hot-water cylinder. The water is heated by a boiler or immersion heater.  The toilet and cold water tap in the bathroom also get their supply from the loft tank. Only the kitchen tap provides fresh drinking water.

The direct system supplies water from the mains – therefore no storage tank is required. Hot water is supplied by a combination boiler. All taps have high, mains pressure and provide drinking water. This system is more efficient and economical as water is only heated when needed. However, if you need to use more than one tap at the same time, you may find that only one of them flows hot water.

Locating stopcocks

First look for the water company’s stopcock. This is normally located in front of the property. Using a special long "key" you can shut off the water supply to the house.

There is also a main stopcock located in your house, most likely under the kitchen sink. It can be used to turn off the water supply. For most jobs it’s sufficient just to turn this off.

The storage tank in the loft also has its own stopcock, normally on the supply feed pipe to the tank. This allows you to isolate the supply to the bathroom but you can still have cold water in the kitchen.

If you want to repair taps, radiators, washing machines etc, you don’t always have to turn off the mains stopcock. If the water-pipes to taps & appliances have a valve on them, you can turn these off to isolate a particular device for repair or decoration.

The next article will tell you how to switch off and drain the water system.

Read more about identifying your gas & electricity supply.