Where to Find Your Stopcock Valves
How to Locate the Stopcock Valves in Your House
As a general rule, start at the easiest place and work back towards the main stopcock valve.
1. Bathroom appliances sometimes have stopcock valves for each supply pipe, or one set that shuts off all the bathroom water. Be prepared for them to be hidden behind the bath panel or any boxing-in that’s been used to conceal the pipes.
All hot water
2. If you can’t find any local stopcock valves, the ideal place to turn off all the hot water is at the cold feed to the hot water cylinder or heater. Look for a stopcock valve near the base, and check that the pipe it’s on feels cold.
All hot water and all cold water not mains fed
3. Often, stopcock valves are fitted to the feed pipes from the storage tank to the hot cylinder and bathroom cold taps.
Failing this, you can isolate all pipes that aren’t on the rising main by shutting off the supply to the tank and then draining it down by turning on all the cold taps. This will take some time, and can leave the system prone to airlocks, so only try it as a last resort.
If there is no stopcock valve on the supply pipe (the one feeding the ballvalve in the tank), tie up the ballvalve itself as shown.
Kitchen cold tap and appliances
4. There may be a stopcock valve somewhere in the kitchen to shut off the branch of the rising main that feeds the sink cold tap. Other kitchen appliances, such as a washing machine or dish washer, should have shut-off valves on both supply pipes. The same goes for other ground-floor appliances fed direct from the rising main, and also for outdoor taps.
5. The rising main stopcock valve shuts off all the water, and it’s rare for houses not to have one (though not impossible). Look for it where the main enters the house: under the stairs or behind the kitchen sink are the most common locations. In flats and maisonettes it will be on the first branch off the main supply to the rest of the building, probably near the sink or the water heater.
6. Sometimes, however, the main stopcock valve is found under the floorboards — often near the front door, or, if the kitchen has been extended, where the old sink was.
Search for a small section of floorboard that looks as if it has been cut and lifted in the past. Lever it up with a bolster chisel (at a pinch, use a garden spade).
7. Most houses also have a water authority stopcock valve which isolates the entirebefore it enters the building, so if all else fails you can try this. You’ll find it under an iron cover on the pavement, or in the garden near the road. The stopcock valve itself will be about lm (3ft) below the ground, and may be covered by layers of mud; dig this out by hand with a piece of coat hanger wire.
To turn the stopcock valve, you need a special key (available from plumber’s merchants) or a strong piece of wood with a V shaped notch cut in the end. Alternatively, the engineer’s department of your local water authority will do it for you, but give them a day’s notice.
Take it in turns
” If the stopcock you’re dealing with controls water under mains pressure, note on the label how many turns it takes to shut it off, and turn it on again by the same amount. Stopcock valves are often used to reduce the water flow slightly in areas where the mains pressure is high, in which case opening them fully could cause hammering in the pipework.
It’s also a good idea to follow the old plumber’s rule: ‘never assume a stopcock works until you’ve tried it’; often they don’t, and you need to try another one further down the line. ”