01 Sept 2026
Water is coming out of somewhere it should not, and you have just realised you do not know where your main stopcock is. Finding it is ten minutes of work on a calm afternoon rather than a frantic search across a wet floor. Here is where to look, and how to work the valve.
Three levels of shut-off, not one
Most homes have more than one place to stop water, and the right one depends on what is happening.
- The isolation valve at the fitting. A small valve on the pipe behind a tap, cistern, sink or water heater. It stops that one fitting and leaves the rest working.
- The main stopcock. One valve that shuts the whole unit off. This is what you reach for when water is escaping and you cannot tell where from.
- The supply side. The meter and whatever sits at the building or the boundary. In flats this is often not yours to touch.
Use the smallest one that solves the problem. If a tap is spraying, the isolation valve under it is enough.
HDB flats
In most flats the stopcock is in the kitchen, high up near the ceiling on the incoming pipe above or beside the sink. In many blocks it sits inside the kitchen service duct alongside the water meter, behind a panel you may never have opened.
Other layouts put it above the bathroom door or near the water heater. If you have an instant heater there will be a valve at the heater itself, and that is not the main stopcock even though it looks much the same.
Look for a lever or a small round wheel on a pipe entering the flat. If there is more than one valve, the main one is on the pipe everything else branches off.
Condominiums
Condos vary far more, because the layout follows the developer rather than a standard plan.
The usual places are the service duct or riser cupboard in the corridor outside your door, a utility or yard area inside the unit, under the kitchen sink where the supply comes in, or behind an access panel in a bathroom ceiling. In plenty of developments the meter and the main valve sit outside the unit entirely, in a riser that may be locked. Ask your managing agent where yours is, and whether residents can reach it, before you need to know.
Landed homes
In a landed property the main control is usually outside, near the water meter at the boundary: a small chamber set into the ground close to the gate or the front wall.
There is frequently a second valve where the supply enters the house, which is the more practical one day to day, plus separate valves for an outside tap or a storage tank. Older houses can have several, added by different people over the years, so trace the pipe rather than guessing.
How to actually turn it
Two shapes, two behaviours.
- A lever, quarter turn. Handle in line with the pipe means open. Handle across the pipe means closed.
- A round wheel or small tap handle. This is a gate valve. Turn it clockwise to close and expect several full turns before it seats.
Then confirm it worked: open the lowest tap and let it run until it stops. If it keeps running steadily the valve has not closed, so move to the isolation valves instead.
If it will not turn
Do not put a wrench on it and lean. A gate valve that has not moved in years can seize, and forcing it can shear the spindle or start it weeping at the packing nut, which turns one problem into two while the floor is still wet. If it will not move under firm hand pressure, stop and use the isolation valves instead.
This is the honest catch in the usual advice to exercise your valves yearly. Turning an old valve keeps it free, and turning a tired one can also be what starts it leaking. If yours has not moved in years, try it while someone who could replace it is in the home rather than alone at midnight.
Do this now, not later
- Find yours, photograph it, and show everyone else who lives there.
- Check that it turns, gently, then turn it back.
- Note the isolation valves under the sinks, at the toilets and at the heater.
- If you rent, tell your landlord if the valve is seized or missing.
Five minutes now is the difference between a wet patch and a flooded floor. There are more short answers on stopcocks and shut-offs on our FAQ page.
When to call a plumber
Call once the water is off and the fault needs fixing, or immediately if you cannot stop it. Our emergency plumbing line runs around the clock and we work islandwide, and if you are still hunting for the valve when you call, describe your kitchen and we will talk you through the likely spot. If the water came from under a sink, the culprit is often a braided hose, which our post on a burst flexible hose covers.