Dripping tap? Find the leak and decide whether to repair it
A drip from the spout points to a different part than water at the handle, tap base, flexible hose, or sink trap. Identify the source before buying anything.
“The tap is leaking” can mean at least five different things: a drip from the spout, moisture around the handle, water at the tap base, a supply-hose leak below the sink, or a waste-pipe leak that only appears when water drains. Find the source before dismantling the tap.
PUB's leak guidance notes that even a dripping tap wastes water and recommends prompt repair; see its tips for finding leaks at home. The repair may be small, but the replacement part is not necessarily generic.
Find exactly where the water appears
| Leak location | Possible source | What to check |
|---|---|---|
| Spout drips while closed | Washer, cartridge, seals, grit, or valve seat | Tap type, brand, model, and exact replacement part |
| Handle or control leaks in use | Stem seal, O-ring, cartridge, or loose component | Where moisture starts as the handle moves |
| Water around tap base | Base seal, loose mounting, internal leak, or splashing | Dry the area and distinguish runoff from fresh seepage |
| Hose or valve below sink is wet | Flexible hose, connector, angle valve, or condensation | Corrosion, bulging, fraying, and the first wet point |
| Trap leaks only while draining | Waste joint, seal, crack, or blockage | Fill and drain a small amount while watching the joints |
To trace an under-sink leak, dry every surface, place clean tissue around separate joints, and run a small amount of water while watching from a safe position. A supply-side leak can continue when the tap is off; a waste-side leak generally appears when water leaves the basin.
Washer, cartridge, or something else?
Traditional screw-down taps commonly use a washer and valve seat. Quarter-turn taps and single-lever mixers commonly use ceramic or other cartridges. Two taps that look similar can have different cartridge dimensions, spline patterns, heights, hot/cold orientation, or seals.
Do not order a part from appearance alone. Find the brand and model, consult the manufacturer or supplier, and photograph the original part during disassembly. If the valve seat or tap body is damaged, replacing a washer or cartridge may not solve the leak.
Safe isolation before any repair
- Clear the cabinet and place a tray and towels below the fittings.
- Identify the angle valve or other isolation serving the tap. Mixer taps may have separate hot and cold supplies.
- Close the correct valve gently; do not force a seized handle.
- Open the tap and verify flow has stopped before dismantling anything.
- Plug the basin waste so screws and small parts cannot fall into it.
If isolation does not stop the flow, close the known unit main valve or call a plumber. Do not start with a live supply. A perished, bulging, or spraying hose should be treated as an urgent water-leak emergency.
A careful DIY repair sequence
Follow the manufacturer's instructions for the exact tap. In general, photograph each stage, protect the finish with a cloth, keep parts in order, and replace the specified washer, O-ring, seal, or cartridge with an exact compatible part. Clean mating surfaces without scratching them.
Reassemble by hand first so threads start correctly. Tighten only as the manufacturer specifies; over-tightening can distort seals, crack plastic nuts, damage ceramic parts, or strip threads. Reopen the supply slowly, purge air, and test the tap through its full range while checking above and below the sink.
Leave dry tissue around the repaired joints for several minutes, then check again later. A repair is not finished until the supply-side and waste-side joints remain dry.
When to stop and call a plumber
- The isolation valve is seized, leaking, or does not stop the flow.
- Connections are corroded, cracked, cross-threaded, or inaccessible.
- The tap has no identifiable replacement parts or instructions.
- A flexible hose is damaged, bulging, frayed, or spraying.
- The valve seat or tap body appears pitted or cracked.
- The leak persists after correct reassembly and testing.
PUB lists replacing taps, mixers, and flexible hoses among simple plumbing works. Work beyond the listed simple tasks may require a PUB Licensed Plumber, especially where regulated water-service or sanitary piping is altered.
Repair or replace?
Repair is attractive when the tap body is sound, the exact part is available, and access is straightforward. Replacement may be more sensible when the body is corroded or cracked, several parts are failing, compatible parts are unavailable, or repeated disassembly costs more than a reliable new fitting.
Send SparkFlow's leaking-tap repair service photos of the tap, handle, brand marking, leak location, and under-sink connections. If water appears only while the basin drains, our clogged-drain guide will help distinguish a waste-joint problem from the tap itself.
Frequently asked questions
- Why does my tap drip after I close it?
- A worn sealing part is common, but the exact part depends on the tap. Screw-down taps may use a washer and valve-seat arrangement; quarter-turn or mixer taps often use a model-specific cartridge. Grit, a damaged seat, incorrect assembly, or excessive pressure can also contribute.
- Can I repair a leaking tap myself in an HDB flat?
- PUB lists replacing taps, mixers, and flexible hoses among simple plumbing works, but you still need the right part and a reliable isolation valve. Stop if the valve is seized, fittings are corroded, the tap is inaccessible, or you cannot confirm a watertight reassembly.
- How do I isolate one tap?
- Many sinks have one or two angle valves below them, but layouts vary. Confirm which valve serves the tap, close it gently, then open the tap to verify the flow has stopped. Do not force a seized valve; use the unit's main shut-off or call a plumber instead.
- Why is there water under my sink?
- Dry the area and use tissue to trace fresh moisture. Possible sources include the tap base, inlet hoses, angle valves, connectors, sink seal, overflow, or waste trap. A spraying supply-side leak needs the water isolated promptly; a waste-side leak appears only when the sink drains.
- Should I replace the whole tap or only the cartridge?
- Repair makes sense when the exact part is available and the tap body, threads, seat, hoses, and finish are sound. Replacement may be more reliable when the body is corroded or cracked, parts are unavailable, several components are failing, or access makes repeated labour impractical.