Why does my outside tap drip after I turn it off?
A dripping garden tap is nearly always a perished washer or a scored seat, and both are fixable in half an hour with the tap still on the wall.
- Difficulty
- beginner
- Time
- 30 min
- Read
- 5 min
- Safety
- caution
Short answer
Isolate the tap at the service valve inside the wall, open it to release the pressure, unscrew the headgear and replace the washer. If it still drips, the seat is scored and needs re-seating or a seat insert. A drip from the spindle rather than the spout is the gland, which just needs tightening.
Garden taps drip more than indoor taps, and for good reasons: they are used hard, closed hard, exposed to frost, full of grit from the mains, and often never serviced. The repair is the same as any traditional tap and it is a genuinely satisfying half hour, but the reason to do it promptly is the frost — a tap that dribbles all winter is a burst pipe waiting for the thaw.
Safety
What you'll need
- An adjustable spanner
- A replacement tap washer of the correct size
- A screwdriver
- PTFE tape (optional)
- A tap reseating tool or nylon seat inserts (optional)
Step by step
- Find the isolating valve.A properly fitted outside tap has a service valve on the pipe inside the wall, usually just behind where the tap comes through, in a kitchen or utility cupboard. Turn it so the slot is across the pipe. If there is no isolating valve, you need the main stopcock — and adding a service valve should be on your list.
- Open the tap to release the pressure.With the supply isolated, open the tap fully so the residual water and pressure drain out. Leave it open while you work.
- Note which sort of tap you have.A traditional bib tap with a rising spindle and a washer, or a modern quarter-turn ceramic disc type. Ceramic taps have no washer — they have a cartridge that is replaced whole, and a quarter turn from off to full on is the giveaway.
- Undo the headgear.On a bib tap, hold the tap body with one spanner and undo the large hexagonal headgear nut with another, anticlockwise. Holding the body matters — twisting the whole tap in the wall breaks the joint inside.
- Replace the washer.On the bottom of the headgear is a jumper with a rubber washer, held by a small nut or simply pushed on. Fit a new washer of the same diameter. If the jumper spins freely and will not undo, replace the whole jumper and washer assembly rather than fighting it.
- Look at the seat while it is apart.Shine a torch into the tap body at the brass seat the washer closes onto. If it is pitted, grooved or scaled, a new washer will drip again within weeks. A reseating tool cuts it flat, or a nylon seat insert presses in over the damaged seat.
- Reassemble and test gently.Wind a few turns of PTFE round the headgear thread, do it up firmly but not brutally, close the tap, open the isolating valve slowly and check for leaks at the headgear and at the wall joint.
- Deal with a spindle drip separately.Water appearing around the spindle when the tap is open, rather than from the spout when it is closed, is the gland. Tighten the small gland nut under the handle by an eighth of a turn, or repack it with PTFE wound into the recess.
Tips
- Buy an assorted pack of tap washers rather than one. They cost very little and the right size is never the one you guessed.
- If there is no isolating valve on the supply to the tap, fitting one is a small job that transforms every future repair and makes the autumn drain-down possible.
- Do this before the first frost. A dripping tap in a hard winter freezes at the tap and splits the pipe in the wall.
- Take a photo of the assembled tap before you take it apart, particularly the order of the washers and the handle fixing.
If it doesn't work
Drips from the spout when closed
Cause: Perished washer, or a scored seat — Fix: New washer first. If the drip returns quickly, the seat is damaged and needs reseating or an insert.
Drips from around the handle when running
Cause: The gland packing has failed — Fix: Tighten the gland nut an eighth of a turn. If that does not do it, repack with PTFE tape wound into the gland recess.
Quarter-turn tap dripping
Cause: The ceramic disc cartridge has worn or has grit in it — Fix: The cartridge is replaced as a unit. Match it to the tap — cartridges are not universal, so take the old one to buy the new one.
Drip started after a mains repair in the street
Cause: Grit disturbed in the main has lodged on the seat — Fix: Strip and clean the seat and washer. It often recurs for a few weeks after mains work anywhere nearby.
Tap turns but water keeps flowing
Cause: The jumper has separated from the spindle, so turning the handle no longer moves the washer — Fix: Strip the headgear and refit or replace the jumper assembly.
Tap moves in the wall when you turn it
Cause: The wall plate or the fixing has worked loose — Fix: Refix the tap properly before doing anything else — a tap that rotates is stressing the pipe joint inside the wall, which is the joint you cannot see and cannot easily reach.
Questions people ask
Does the double check valve need replacing too?
An outside tap must have backflow protection, usually a double check valve on the supply. It is a separate fitting from the tap and does not cause a drip from the spout, but if the tap is being replaced entirely, check the protection is present and sound.
My tap has a hose connected all the time — is that a problem?
A hose left permanently connected, especially one lying in a pond or a butt, is a backflow risk, which is exactly what the check valve protects against. It is also the reason the check valve is required.
Should I replace the tap instead of repairing it?
If the body is corroded, the thread is damaged or it moves in the wall, replacement is sensible. A sound tap with a worn washer is worth repairing — it takes half an hour and the parts cost almost nothing.