A stopcock usually leaks either from around the spindle, where the handle enters the valve body, or from the joints where it connects to the pipe. WaterSafe explains that water rising from the spindle often points to the gland nut, while water around the joints is usually caused by loose or worn nuts and seals.
Where the water appears is the most useful clue. It helps show which part needs attention and whether a repair is likely to be enough.
Leaks Around the Spindle
The spindle turns to open and close the valve. Around it sits a gland nut with packing or an O-ring that keeps water in. When this packing wears, dries out or is disturbed, water can seep up around the spindle.
These leaks often appear just after the stopcock has been turned, especially if it had not been used for a long time. Movement can unsettle old packing that had been sealing well while left alone.
A small adjustment of the gland nut, or renewing the packing, can sometimes stop this type of leak. Over-tightening can make the stopcock very stiff or damage it, so care is needed.
Leaks at the Pipe Joints
Most stopcocks connect to the pipe with compression joints. Each joint has a nut and an olive that grips the pipe. If a nut has loosened or the olive is damaged, water can weep from the joint.
Old or corroded pipework around the stopcock can also be a factor. If the pipe itself is pitted or thin, the joint may not seal well even after work on the nut.
Pipes that are knocked, or a stopcock that has been pulled while someone tried to turn it, can strain these joints too.
Leaks From the Valve Body
Water appearing from the body of the stopcock, rather than a joint or the spindle, may point to a crack or corrosion. This is less common but more serious, as it cannot usually be fixed with a seal.
In that situation, replacement may be the more practical option. Each case depends on the valve and pipe condition, so it should be assessed before deciding.
What to Do Now
Place a container or towel under the stopcock and keep the area dry. Check it regularly to see if the drip is getting worse.
Do not force the stopcock to test it, and avoid taking it apart while the water is on. If the leak grows and the indoor stopcock cannot be used safely, the outside stop tap may be an option if you can reach it and it turns freely.
If your stopcock is dripping, our Oxford stopcock repairs can find where the water is escaping and renew the packing, seals or joints involved. If the valve turns out to be beyond repair, you will know why before deciding on the next step.