How to change a tap washer

Inspired by a helpful YouTube guide. This walk-through is based on the "How to Change a Tap Washer" video on YouTube, which runs through the job cleanly from start to finish. The close-up shots of the washer, jumper, and tap seat make the process far clearer than words alone — worth a watch before you reach for the spanner.

1. Turn off the water supply to the tap

Look under the sink or basin for isolation valves — the small slotted valves fitted to the hot and cold supply pipes. Turn them clockwise with a flat-head screwdriver until the slot sits at ninety degrees to the pipe. That closes them off.

If there are no isolation valves, you will need to use the main stopcock instead, usually found under the kitchen sink or where the supply enters the house. Turn it clockwise to close it. Open the tap fully and let any remaining water drain away before you start.

2. Remove the tap handle

Prise off the decorative cap on top of the tap handle — usually a small hot or cold indicator that pops off with a flat-head screwdriver. Underneath you will find a retaining screw. Undo it and lift the handle straight off.

Some handles grip the spindle very firmly. A firm upward pull usually frees them. Mind you, if you are wrestling with it, stop and check the screw is fully out before you try again — forcing it can crack older handles.

3. Unscrew the tap headgear

Below the handle sits the headgear — a large brass nut that holds the whole mechanism in the tap body. Fit an adjustable spanner or basin wrench onto the flats and turn it counter-clockwise to loosen it.

Support the tap body with your other hand while you apply force. Old pipework can be more flexible than you expect, and you do not want to twist the supply pipe behind the wall. Once loose, lift the headgear out cleanly.

4. Take out the old washer

The washer is at the bottom of the jumper — the spindle section that sits at the end of the headgear. It is either held by a small brass nut or pressed onto a peg. Undo the nut if there is one, then peel the old washer off.

Take the old washer with you to a plumber's merchant or hardware shop to match the size. That said, 12 mm and 19 mm are the most common sizes for UK kitchen and bathroom taps, so it is worth knowing which one you have before you go.

5. Fit the new washer

Push the new washer firmly onto the jumper peg, or refit the retaining nut if there is one. It should sit flat and centred — not at an angle. A washer that is even slightly canted will drip as soon as you run the tap.

While you have the headgear out, take a quick look at the O-rings on the spindle. If they look cracked, hard, or perished, replace them at the same time. They are cheap and save you taking the tap apart again a few months later.

6. Check the tap seat

Peer down into the tap body with a torch. You are looking at the tap seat — the small circular brass rim that the washer presses against to form a seal. If it looks smooth and clean, you are fine.

To be fair, pitted or grooved tap seats are more common on older taps than people expect. A brand-new washer pressing against a roughened seat will still drip. A tap reseating tool (usually five to ten pounds from a plumber's merchant) grinds the seat back to a clean, flat surface and is well worth keeping in the toolbox.

7. Reassemble the tap and test

Lower the headgear back into the tap body and screw it clockwise until it is firm. Snug is enough — do not overtighten, especially on older brass fittings, as the threads can crack or strip. Refit the handle, tighten the retaining screw, and snap the cover cap back on.

Open the isolation valve slowly, then gently turn the tap on and off. The drip from the spout should have stopped. If there is a small weep from around the handle or spindle rather than the spout, the O-ring is usually the culprit — the repair is the same: tap off, headgear out, swap the ring, rebuild.

When to call a handyman

Call Richard if the isolation valves are seized, the stopcock will not budge, or the tap body is cracked or corroded. If you have fitted a new washer and the drip persists, the tap seat may need reseating or the tap itself may need replacing. The Sandwich Handyman can help with tap repairs, washer replacements, and small plumbing jobs around the home in Sandwich and across East Kent.