A stopcock usually leaks because the packing around the spindle has worn, a joint on either side has loosened, or an inner washer or seal has failed. Most leaks start small, so the best thing to do is catch the drips, avoid forcing the valve and get it checked soon. Corrosion on older valves can also play a part.
Where a Stopcock Leak Usually Comes From
Your stopcock is the valve that controls the cold water coming into your home. It is often under the kitchen sink.
The most common leak point is around the spindle, just under the handle. Inside is a gland packing or seal that stops water escaping as the spindle turns. Over time this packing dries out or wears, and a slow weep may appear when the valve is moved.
Leaks can also come from the compression joints on each side of the valve. These joints can loosen with age, pipe movement or temperature changes. Inside the valve, a worn washer may mean it no longer shuts off fully, even when no water is dripping outside.
Older stopcocks can show green or white crusty deposits. This corrosion can be associated with slow leaks and may weaken the valve body over time.
Safe Steps to Take Straight Away
Put a towel around the valve and place a bowl or tray underneath to catch drips. Move anything that could be damaged. If water is near any sockets or electrics, keep clear and get an electrician to check them.
Try not to overtighten the gland nut or the joints. A small turn can sometimes help, but too much force can crack fittings or damage old pipework. Never use a long lever or hammer on a stiff handle.
If the stopcock itself is leaking badly and you cannot stop the water, the outside stop valve may be the next option. Thames Water says the outside stop valve should only be used in an emergency, and it is usually under a small cover on the path or pavement. If you cannot find it or it will not turn, call your water supplier or a plumber.
Signs the Leak Is Getting Worse
Keep an eye on the area for a day or two. Warning signs include drips that become a steady trickle, water pooling in the cupboard, or damp spreading into the floor or skirting board.
Other signs include a handle that has become very stiff or loose, or a valve that no longer shuts the water off properly. Any of these suggest the valve needs attention rather than more waiting.
When to Call a Plumber
A leaking stopcock is not something to ignore, because you rely on it in an emergency. A plumber can check whether the valve needs new packing, a tightened joint or a full replacement. Our page on stopcock repair and replacement in Swindon explains how this work is usually carried out.
If your stopcock has started to weep or drip, Emergency Plumber Swindon can take a look and talk you through the options. Give us a call on 01793 569521 and we will help you decide on the next step.