How Do You Diagnose and Fix a Dripping Tap - Step by Step?

[Taker00]

Can we fix this between us? A leaky/dripping tap? or am I having to call out a plumber

[GhostRider]

A dripping tap is the most common plumbing repair homeowners face and one of the most achievable DIY fixes requiring no special skills or unusual tools. The approach differs slightly between the two main types of tap mechanism: the traditional rubber washer tap found in older UK homes and the more modern ceramic disc cartridge tap found in most post-1990s fittings.

Before starting any tap repair, the most important step is turning off the water supply. For a kitchen or bathroom basin tap this is usually done at the isolating valve, a slot-headed valve on the supply pipe under the sink, which you turn a quarter turn to close. If no isolating valve exists or it does not fully close, you will need to turn off the water at the main stopcock, usually under the kitchen sink or where the water supply enters the house. Open the tap fully after turning off supply to drain any remaining water in the pipe.

For a rubber washer tap, the drip almost always comes from a worn washer. Remove the tap handle, which is usually held by a screw under a decorative cap on top of the handle. Remove the packing nut beneath the handle, which may require a spanner, then lift out the headgear assembly. The rubber washer is at the bottom, held by a small screw. Replace it with a washer of the same size, reassemble in reverse order, turn the water back on and test.

For a ceramic disc cartridge tap, the cartridge itself needs replacing rather than a component within it. The cartridge is a sealed unit that slides in and out once the handle and retaining nut are removed. Take the old cartridge to a plumber's merchant to match it as cartridges are not universal. Some are hot side, some cold, some are quarter-turn, some are half-turn, and getting the wrong one produces a tap that does not function correctly even if it fits.

If the tap drips from around the base of the spout rather than from the spout itself, the issue is the O-ring seals on the body of the tap rather than the washer or cartridge.

[EventHorizon]

The isolating valve identification step being skipped is what turns a twenty-minute repair into a whole-house water-off situation. Worth knowing where every isolating valve and the main stopcock is before you need them rather than when you need them

[Stuart_67]

Taking the old washer or cartridge to the merchant rather than trying to match from a photo or description online is the step that prevents making a second trip. Plumbing parts have enough variation in size and specification that having the part to match against is much faster

[BradBytheway]

The O-ring drip at the base being a different problem from the spout drip is worth knowing because the fix is different. Many people replace the washer when the problem is an O-ring and the drip continues from the same place with a new washer

[HeartbreakKid92]

Penetrating oil applied to stiff packing nuts and left for thirty minutes before attempting to remove them saves stripped hexagons and broken heads. Old plumbing fittings can be extremely stiff and forcing them dry is how you create a bigger problem than a dripping tap

[WWEHarry78]

Most modern ceramic disc taps can be refurbished with a replacement cartridge for under twenty pounds and twenty minutes of work. The alternative is paying a plumber who will charge at least a hundred pounds for the same job. This is one of the clearest cost-benefit DIY cases

[CrimsonNova71]

Ceramic disc cartridges being handed, with hot and cold versions that look almost identical, is the detail that catches people out. If you fit a cold cartridge on the hot side the tap will produce cold water when turned to hot and the reverse. Confirming which side you are working on before ordering saves a second trip