A dripping tap might seem like a minor annoyance, but even a slow drip can waste thousands of litres of water a year — and add noticeably to your water bill. The good news is that many tap repairs are straightforward enough for a confident DIYer to tackle. Here's how to diagnose the problem, fix it safely, and know when it's time to call in a pro.
Is It Legal for Me to Fix My Own Tap in NZ?
Before you grab a spanner, it's important to understand NZ's rules around plumbing work. Under the Plumbers, Gasfitters and Drainlayers Act 2006, most plumbing work on your home's water supply or drainage system is restricted work and must be carried out by a licensed tradesperson. However, there is a specific homeowner exemption that allows you to do like-for-like maintenance on your own home — such as replacing washers, O-rings, and tap cartridges — provided you own and occupy the property. You cannot do this work on a rental property. If in doubt, check with the PGDB or hire a licensed plumber.
What Causes a Tap to Drip?
Most dripping taps come down to a few common culprits:
- Worn washers – the most common cause in older-style jumper valve taps
- Faulty O-rings – rubber seals that wear out over time, often causing leaks around the base of the spout
- Worn or cracked cartridge – common in modern mixer taps and ceramic disc taps
- Corroded valve seat – the surface the washer presses against can pit and corrode
- Loose packing nut – sometimes a simple tighten is all that's needed
Identifying your tap type first will save you time at the hardware store.
Tools and Materials You'll Need
- Adjustable spanner or basin wrench
- Flathead and Phillips screwdrivers
- Replacement washers, O-rings, or cartridge (match to your tap brand/model)
- Plumber's grease (silicone-based)
- A cloth or small towel
- Bucket or bowl
Replacement washers and cartridges are widely available at Bunnings and Mitre 10. Take the old part with you to match it up, or note your tap brand and model before you go.
Step-by-Step: Fixing a Dripping Tap
1. Turn Off the Water Supply
Locate the isolating valve under the sink or vanity and turn it clockwise to shut off the water. If there's no isolating valve, you'll need to turn off the water at the toby (main stopcock), usually near your boundary or water meter. Turn on the tap to release any remaining pressure and water.
2. Remove the Tap Handle
Prise off the decorative cap on top of the handle (if present) and unscrew the handle screw. Lift or pull the handle off. Some handles are held on with a grub screw on the side.
3. Access the Internals
Use an adjustable spanner to unscrew the packing nut or bonnet nut — this holds the tap mechanism in place. Turn anticlockwise to loosen. Once removed, you can pull out the spindle (for washer-type taps) or cartridge (for mixer/ceramic disc taps).
4. Replace the Worn Part
For washer taps: Unscrew the old washer from the bottom of the spindle and press in a new one of the same size. Apply a little silicone plumber's grease.
For cartridge taps: Pull out the old cartridge (note which way it's oriented) and push in the new one in the same direction. Many NZ homes have Methven, Dorf, or Caroma taps — cartridges for these brands are generally available at plumbing merchants or hardware stores.
For ceramic disc taps: Remove the ceramic disc assembly and inspect for cracks or grit. Clean or replace as needed.
5. Reassemble and Test
Reassemble in reverse order — spindle or cartridge, packing nut, handle, and cap. Don't overtighten. Slowly turn the water supply back on and check for leaks. Run the tap a few times to confirm the drip is gone.
Tap Types at a Glance
| Tap Type | Common In | Usual Fix |
|---|---|---|
| Jumper valve (washer) tap | Older NZ homes | Replace rubber washer |
| Mixer tap (cartridge) | Modern kitchens/bathrooms | Replace cartridge |
| Ceramic disc tap | Mid-range to premium fittings | Clean or replace disc |
| Ball valve tap | Some kitchen mixers | Replace ball and seats kit |
When to Call a Professional
Some situations are best left to a licensed plumber:
- You can't find or shut off the water supply — don't risk flooding your home
- The tap body or valve seat is corroded or cracked — this often requires replacing the whole tap, which is restricted work
- You're renting the property — all plumbing repairs in rental homes must be done by a licensed tradesperson under the Healthy Homes Standards
- The leak is coming from the pipes, not the tap itself
- You're not confident — there's no shame in calling a pro
A qualified local plumber can be found quickly on tradedirectory.co.nz.
A Note on Water Efficiency
NZ's BRANZ research highlights that leaking taps are one of the most common sources of household water waste. If you're upgrading your tap at the same time, look for WELS-rated (Water Efficiency Labelling and Standards) fittings — the more stars, the more water-efficient.