How to Replace a Leaking Tap Washer

🔧 How to Replace a Leaking Tap Washer — Australian DIY Trade Guide

Plumbing work in Australia must be performed by a licensed plumber. This guide explains the process and helps you select the right tools and materials.

What is involved in replacing a leaking tap washer in Australia?

Replacing a leaking tap washer is one of the most common plumbing maintenance jobs in Australian homes, especially on older compression-style taps. In many cases, a steady drip is caused by a worn rubber washer, jumper valve, or damaged valve seat.

This guide explains how to identify the tap type, safely isolate the water, remove the tap assembly, replace the washer, and reassemble the tap correctly. For anything involving concealed pipework, failed isolation valves, or persistent leaks after repair, contact a licensed plumber in accordance with the PCA and AS/NZS 3500.

What skill level is required for tap washer replacement?

Beginner — Estimated time: 0.5 to 1.5 hours

What tools are essential for replacing a tap washer?

What materials are needed for a tap washer repair?

What safety precautions are necessary before replacing a tap washer?

Step-by-Step Guide

Step 1: Identify the tap type

Most leaking washer repairs apply to older compression taps, where you turn the handle multiple times to open and close the water. These taps usually use a rubber washer on the end of the spindle to seal against the valve seat.

If your tap is a quarter-turn mixer, ceramic disc tap, or monobloc mixer, it may not use a traditional washer. In that case, the issue may be a ceramic cartridge, O-ring, or mixer cartridge rather than a standard tap washer.

💡 If the tap drips from the spout when turned off, the washer or seat is often the problem. If water leaks around the handle, the spindle O-ring or packing may be worn.

Step 2: Isolate the water supply

Turn off the water to the affected tap. If there is an under-sink or local stop tap, isolate it there. If not, turn off the mains water supply to the house.

Open the tap fully to drain residual water and confirm the supply is off. Keep a bucket or tray underneath the work area to catch any remaining water.

⚠️ If the tap still runs strongly after isolation, do not continue. The isolation valve may be faulty and a licensed plumber should attend.

Step 3: Remove the tap handle

Look for the decorative cap on top or front of the tap handle, usually marked hot or cold. Carefully pry it off with a small flat-head screwdriver.

Undo the handle screw beneath the cap, then lift the handle off the spindle. If it is stuck due to corrosion or mineral build-up, gently wiggle it free rather than forcing it.

💡 Some older handles seize onto the spindle spline. A small handle puller can help avoid damaging the tap body or cracking the handle.

Step 4: Remove the tap bonnet and spindle

Place a soft cloth around the chrome bonnet or cover to prevent marking. Use an adjustable spanner or tap spanner to undo the bonnet anti-clockwise.

Once loosened, withdraw the spindle assembly from the tap body. This is the internal mechanism that carries the washer, jumper valve, and seals.

Inspect the spindle thread and body for wear, corrosion, or heavy mineral scale. Clean any debris before proceeding.

Step 5: Inspect the washer, jumper valve, and seals

At the bottom of the spindle, you will usually find the tap washer secured by a small brass screw. Remove the screw and inspect the rubber washer.

Check for:

If the washer has gone hard or developed an uneven edge, replace it with the same size and style. Common domestic sizes are 12 mm and 15 mm, but always match the original.

Step 6: Check the valve seat inside the tap body

Shine a torch into the tap body and inspect the valve seat, which is the brass surface the washer seals against. If it is rough, grooved, or pitted, a new washer alone may not stop the drip.

Use a tap reseating tool lightly and carefully to dress the seat. Only remove the minimum material needed to create a clean, smooth sealing face.

⚠️ Excessive reseating can permanently damage the tap body. If the seat is badly worn or split, the tap may need a more advanced repair or replacement by a licensed plumber.

Step 7: Fit the new washer and any replacement seals

Install the new washer onto the spindle and secure it firmly with the retaining screw. Do not overtighten the screw, especially on older brass components.

Replace the jumper valve if worn or loose. If the spindle has an O-ring or gland seal, replace that as well to prevent handle leaks.

Apply a small amount of silicone-based plumber’s grease to the spindle threads and O-rings. This helps smooth operation and reduces wear. Do not use petroleum grease on potable water seals.

🪵 Materials note: Use potable-water-compatible tap repair parts suited to Australian tapware and pressure conditions.

Step 8: Reassemble the tap

Screw the spindle assembly back into the tap body by hand first to avoid cross-threading. Then tighten it gently with a spanner until firm.

Refit the bonnet, reinstall the handle, tighten the handle screw, and snap the indicator cap back into place.

Do not crank the tap overly tight in normal use. Compression taps should close firmly, but excessive force shortens washer life.

Step 9: Restore water and test the repair

Slowly turn the water supply back on. Open the tap slightly to allow air to purge, then close it and observe.

Check for:

Run both hot and cold taps if applicable. If the tap still drips after replacing the washer, the valve seat, spindle, or tap body may be damaged.

Step 10: Clean up and monitor

Wipe the tap dry and leave it for several minutes to confirm the drip has stopped. Recheck again after an hour and later that day.

Dispose of old washers and corroded small parts safely. Keep a small assortment of replacement washers for future repairs.

💡 If you have several old taps in the home, replacing all worn jumper valves and spindle seals at the same time can save repeat callouts and future frustration.

Common Mistakes to Avoid

Pro Tips

Recommended Tools

🔒 Licensing: Plumbing work in Australia must be performed by a licensed plumber. This guide explains the process and helps you select the right tools and materials. For compliance matters, check your state regulator such as NSW Fair Trading, VIC VBA, QLD QBCC, or WA Building Commission.