A dripping tap is one of the most common household annoyances in New Zealand — and one of the most wasteful. Even a slow drip can waste thousands of litres of water a year, adding real cost to your water bill if you're on a metered supply. The good news is that many dripping taps can be fixed with basic tools and a trip to your local hardware store.
Why Do Taps Drip? Common Causes
Understanding what's causing the drip helps you fix it properly the first time. The cause usually depends on the type of tap you have.
Jumper Valve / Washer Taps (Traditional Capstan or Pillar Taps)
These are the older-style taps with separate hot and cold handles that you turn clockwise to close. They use a rubber washer (sometimes called a jumper valve) that presses against a brass seat to stop water flow. Over time the washer wears, hardens, or tears — and water sneaks past.
Ceramic Disc Taps
Modern quarter-turn taps use a pair of ceramic discs instead of a rubber washer. These are very durable but can fail if grit or debris scores the disc surface, or if the cartridge cracks.
Ball Taps and Mixer Taps
Single-lever mixer taps use either a ceramic cartridge or a ball-and-spring mechanism. Worn O-rings, a damaged cartridge, or a faulty spring/seat are the usual culprits.
Other Common Causes
- High water pressure — NZ mains pressure can be high enough to force water past worn seals faster than normal. A pressure-limiting valve (PLV) may be needed.
- Corroded valve seat — the metal seat the washer presses against can pit and corrode, meaning even a new washer won't seal properly.
- Loose packing nut — water leaking from around the spindle (not the spout) points to a worn packing washer or O-ring around the stem.
How to Diagnose the Problem
Before grabbing a spanner, spend a few minutes working out exactly what's happening.
- Locate the drip. Is water dripping from the spout, or weeping around the base of the handle/spindle? Spout drips = internal washer or cartridge. Spindle leaks = packing or O-ring.
- Identify your tap type. Quarter-turn (ceramic disc) or multi-turn (washer)? Check under the handle — a screw or grub screw usually holds the handle on.
- Check water pressure. If multiple taps drip or your pipes bang, high pressure may be contributing. A plumber can test this with a gauge.
- Isolate the supply. Turn off the isolating valve under the basin or vanity (turn clockwise). If there isn't one, you'll need to turn off the toby (water meter) at the boundary.
- Open the tap fully after isolation to release pressure and confirm the supply is off.
What You Can Safely Fix Yourself
Replacing washers, O-rings, and ceramic cartridges in existing taps is not restricted work under New Zealand law — homeowners can do this themselves. However, any work that involves connecting or disconnecting water supply pipes, moving fixtures, or installing new tapware is restricted plumbing work that must be carried out by a licensed plumber.
Replacing a Rubber Washer (Traditional Tap)
Tools needed: Adjustable spanner, flathead and Phillips screwdrivers, replacement washers (take the old one to Bunnings or Mitre 10 to match the size).
- Turn off the water supply and open the tap to drain pressure.
- Prise off the decorative cap on top of the handle and undo the screw beneath.
- Pull the handle off. Use a spanner to unscrew the packing nut (turn anticlockwise).
- Lift out the spindle. The washer is held at the bottom by a small brass screw — undo it and swap the washer.
- While you're in there, inspect the valve seat inside the tap body. If it feels rough or pitted, a plumber can re-grind or replace it.
- Reassemble in reverse, turn the water back on slowly, and test.
Replacing a Ceramic Cartridge
- Turn off supply and open the tap.
- Remove the handle (usually a grub screw under a cap).
- Unscrew the cartridge retaining nut and pull the cartridge straight out — note the orientation.
- Take the old cartridge to Mitre 10 or PlaceMakers to find a match, or search by the tap brand.
- Insert the new cartridge in the same orientation, reassemble, and test.
Replacing O-Rings on a Mixer Tap
If water is weeping around the base of the spout or handle, O-rings are likely worn. These are inexpensive and available at any hardware store. The process is similar — isolate, disassemble, swap the O-rings, lubricate lightly with silicone grease (not petroleum-based), and reassemble.
| Tap Type | Likely Fault | DIY Fix? | Difficulty |
|---|---|---|---|
| Traditional washer tap | Worn rubber washer | Yes | Easy |
| Ceramic disc tap | Damaged cartridge | Yes | Easy–Moderate |
| Mixer tap (lever) | Worn cartridge or O-rings | Yes | Moderate |
| Any tap — spindle leak | Packing washer / O-ring | Yes | Easy |
| Corroded valve seat | Pitting/corrosion | Plumber recommended | Requires re-grinding tool |
| High water pressure | PLV needed | Licensed plumber required | N/A |
How to Prevent It Recurring
- Don't overtighten taps. Cranking taps shut hard accelerates washer wear. Turn off gently — just until the flow stops.
- Install a pressure-limiting valve if your mains pressure is high. BRANZ recommends keeping household pressure within safe limits to protect both tapware and appliances.
- Use quality replacement parts. Cheap washers wear faster. Brass-bodied jumper valves outlast all-rubber ones.
- Service tapware periodically. Replacing washers every few years as preventive maintenance is far cheaper than an emergency call-out.
- Consider upgrading old tapware. If your taps are decades old and constantly failing, new ceramic-disc tapware is more reliable long-term — but installation must be done by a licensed plumber.
When to Call a Professional
Call a licensed plumber if:
- You can't isolate the water supply (no isolating valve, or the toby is seized).
- The valve seat is damaged and needs re-grinding or replacement.
- Water pressure is the underlying cause — fitting or adjusting a pressure-limiting valve is restricted plumbing work.
- The tap body itself is cracked or corroded beyond repair.
- You need to replace the tap entirely — connecting to supply pipes is restricted work under the Plumbers, Gasfitters and Drainlayers Board rules.
- You're uncomfortable working with the plumbing or can't stop the leak after attempting a repair.
Safety note: Always confirm the water supply is fully isolated before dismantling any tap. If in doubt, turn off the toby at the boundary. Never work on hot water tapware without also checking that the hot water cylinder pressure has been relieved.
A qualified local plumber can diagnose and fix a dripping tap quickly — often in under an hour. You can find licensed plumbers in your area at tradedirectory.co.nz.
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