A dripping tap is one of the most common household annoyances in New Zealand, and in most older taps it comes down to a single worn-out rubber washer. The good news is that replacing a tap washer is one of the few plumbing tasks a homeowner can legally do themselves — no licence required — and it typically takes less than 30 minutes with basic tools.
Is This Legal for a Homeowner to Do?
In New Zealand, replacing a tap washer is not classified as restricted plumbing work under the Plumbers, Gasfitters and Drainlayers Act 2006. This means you can legally do it yourself without holding a licence. However, any work that involves altering pipework, moving fittings, or connecting to the water supply system is restricted work and must be carried out by a licensed tradesperson registered with the Plumbers Gasfitters & Drainlayers Board. If you're unsure whether your job goes beyond a simple washer swap, check with a professional first.
Tools and Materials You'll Need
Before you start, gather the following:
- Adjustable spanner or shifting spanner
- Flathead and Phillips screwdrivers
- Replacement tap washers (a mixed pack covers most sizes — available at Bunnings or Mitre 10)
- O-rings (worth replacing at the same time if the tap is old)
- Plumber's grease (silicone-based)
- A small container or towel to catch water
- Penetrating oil (e.g. WD-40) if fittings are corroded
Older NZ homes — particularly those built before the 1990s — often have brass jumper-valve taps where the washer sits on a brass jumper. These are very common and easy to service.
Step-by-Step: Replacing the Tap Washer
1. Turn Off the Water Supply
Locate the isolation valve under the sink or basin and turn it clockwise to close it. If there's no isolation valve, you'll need to turn off the water at the toby (main stopcock), usually found near the boundary of your property or under a small lid in the ground outside. Turn on the tap to release any remaining pressure and drain the line.
2. Remove the Tap Handle
Prise off the decorative cover cap on top of the handle (usually a small plastic disc marked H or C). Underneath you'll find a screw — remove it and lift the handle off. If it's stuck, a gentle wiggle usually frees it.
3. Unscrew the Headgear
Use your adjustable spanner to unscrew the headgear (the large hexagonal nut below the handle). Turn anticlockwise. Protect chrome finishes by wrapping the jaws with tape or a cloth. Once removed, you'll see the jumper valve — a small brass or plastic stem with the rubber washer attached at the bottom.
4. Replace the Washer
The washer is held on by a small brass nut or simply pressed onto a peg. Remove the old washer — it will likely be flattened, cracked, or hardened. Match the size carefully before fitting the new one. A washer that's too small won't seal; too large and it won't seat properly. Common sizes are 12 mm and 15 mm. While you have the tap apart, inspect the O-ring on the headgear and replace it if it looks worn.
5. Check the Seat
Look down into the tap body with a torch. The seat (the brass ring the washer presses against) should be smooth. If it's pitted or grooved, the tap will continue to drip even with a new washer. A plumber can re-grind or replace the seat, or you can use a seat grinder tool if you're confident doing so.
6. Reassemble and Test
Apply a small amount of plumber's silicone grease to the O-ring and threads. Reassemble in reverse order — headgear, handle, screw, cap. Don't overtighten the headgear; firm hand-tight plus a quarter turn with the spanner is enough. Slowly turn the water back on and check for leaks around the headgear. Turn the tap on and off a few times to confirm the drip has stopped.
Common Problems and Tips
| Problem | Likely Cause | Solution |
|---|---|---|
| Tap still drips after new washer | Damaged seat | Re-grind seat or call a plumber |
| Leak around headgear | Worn O-ring | Replace O-ring |
| Headgear won't budge | Corrosion | Apply penetrating oil, wait 10 mins |
| Jumper valve missing | Fell into tap body | Fish out with a magnet or tweezers |
Water Saving — Why It Matters
A dripping tap can waste thousands of litres of water per year. With many NZ councils moving toward water metering, fixing a drip promptly saves both water and money. Energywise has useful guidance on reducing household water use.
When to Call a Professional
Call a licensed plumber if:
- The tap seat is badly damaged and needs regrinding or replacement
- You discover corroded or leaking pipework once the tap is open
- The tap is a mixer tap or ceramic disc cartridge type — these require different parts and techniques
- Water won't shut off at the toby and you need emergency help
- You're working on hot water cylinder connections or any gas-related fittings
You can find qualified local plumbers and handymen on tradedirectory.co.nz to get the job sorted quickly and correctly.
Safety Note
Always confirm the water is fully off before disassembling any tap. Keep a towel handy and work over a dry surface. If you're working near an electric hot water cylinder, be aware of the electrical components — do not touch wiring. Electrical work is restricted and must be done by a registered electrician registered with the Electrical Workers Registration Board.
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