A tap usually keeps dripping when it is turned off because the part that seals the water inside it, often a rubber washer or a ceramic cartridge, has worn or been damaged. Limescale, grit or wear on the seat that the washer presses against can also stop the tap closing fully.
A dripping spout is one of the most common tap faults, and it is often repairable. Knowing what type of tap you have can help explain which part is likely to be involved.
Worn Washers in Traditional Taps
Many older-style taps, where the handle turns several times, use a rubber washer. When you close the tap, the washer presses down onto a seat to stop the water. Over time, the washer can harden, split or wear thin, letting a small amount of water through.
A common sign is having to turn the tap off harder and harder to stop the drip. Overtightening can wear the washer faster and may damage other parts, so it is best avoided.
Worn Cartridges in Modern Taps
Many modern taps, including most lever and mixer taps, use a ceramic cartridge. Inside are discs that line up to let water through and turn away to stop it. If the discs are worn, chipped or have grit between them, the tap may drip even when the handle is fully off.
Cartridges vary between makes and models, so the right replacement usually depends on identifying the tap. Fitting the wrong cartridge may not stop the drip and could damage the tap.
Damaged Seats, Limescale and Debris
The seat is the surface inside the tap that the washer closes against. If it is worn or pitted, a new washer may not seal properly. Limescale or small particles carried in the water can also sit on the seat or in the cartridge and stop the tap closing fully.
A tap that drips only on the hot side, or only on the cold side of a mixer, can point to a fault in one part rather than the whole tap. This does not show exactly which part has failed, though.
What to Do About a Dripping Tap
Avoid forcing the handle tighter, as this can make the problem worse. If the drip is heavy and there is an isolating valve on the pipe under the sink, closing it, if it turns easily, can stop the drip until the tap is repaired.
A plumber can check whether a new washer or cartridge will fix it or whether the seat or tap body is damaged. Our page on leaking tap repair in Poole explains how dripping taps are assessed and repaired.
If a tap keeps dripping at your Poole home or business, a plumber can find the cause and explain the repair options.