How to Fix a Leaking Tap: Complete DIY Guide for NZ Homes

1. Compression (Traditional) Taps

Also known as pillar taps or traditional taps, these are the most common in older NZ homes. They have separate hot and cold taps with handles that turn multiple times to open and close.

How to Identify:

• • Requires multiple turns to fully open or close
• • Separate taps for hot and cold water
• • Traditional cross-head or capstan handles
• • More common in homes built before 1990

Common Problems:

• • Worn washers (most common)
• • Damaged O-rings
• • Corroded valve seats
• • Loose packing nuts

2. Mixer Taps

Modern taps that combine hot and cold water through a single spout. They can have separate handles (dual-handle mixer) or a single lever controlling both temperature and flow (single-lever mixer).

Types of Mixer Taps:

• •
  Dual-handle mixers: Two handles control hot and cold water separately but mix at the spout. Similar repair process to compression taps.
• •
  Single-lever mixers: One lever controls both temperature (left-right) and flow (up-down). Uses ceramic disc or cartridge mechanism.

Common Problems:

• • Worn ceramic disc cartridges
• • Damaged seals and O-rings
• • Loose connections at the base
• • Mineral buildup affecting movement

3. Ceramic Disc Taps

Modern taps using ceramic disc technology, which is more durable than traditional washers. They typically require only a quarter turn to open fully.

How to Identify:

• • Quarter-turn operation (90-degree turn from off to full flow)
• • Smooth, easy operation with little resistance
• • More common in homes built after 2000
• • Usually found on modern kitchen and bathroom fixtures

Common Problems:

• • Worn ceramic disc cartridges
• • Seal deterioration
• • Mineral deposits on ceramic discs
• • Rarely: cracked ceramic discs

4. Ball and Cartridge Taps

Less common in NZ but found in some modern installations. Ball taps use a rotating ball mechanism, while cartridge taps use replaceable cartridge units.

Key Features:

• • Single-handle operation
• • Complex internal mechanisms
• • Often brand-specific parts required
• • Generally more expensive to repair

1. Worn or Damaged Washers

The most common cause of leaking taps, especially in compression-type taps. Washers are rubber or fiber discs that create a watertight seal when you close the tap. With repeated use, they wear down, harden, or crack.

Signs of Washer Problems:

• • Dripping from the spout when tap is fully closed
• • Need to turn tap handle tighter and tighter to stop dripping
• • Leak worsens gradually over time
• • More common in hot water taps (heat accelerates wear)

2. Deteriorated O-Rings

O-rings are small rubber rings that seal joints and connections in tap mechanisms. They deteriorate with age, exposure to chemicals, and temperature changes.

Signs of O-Ring Problems:

• • Water leaking around the tap handle or base
• • Leak occurs when tap is running, not when closed
• • Visible water pooling around tap base
• • Leak gets worse when you turn the tap on

3. Corroded Valve Seats

The valve seat is where the tap washer presses to create a seal. Mineral deposits from NZ's water can corrode the valve seat, preventing a proper seal even with a new washer.

Signs of Valve Seat Corrosion:

• • Leak persists even after replacing washer
• • Visible corrosion or pitting on valve seat
• • Rough surface where washer seals
• • More common in areas with hard water

4. Worn Ceramic Disc Cartridges

Modern ceramic disc taps can develop leaks when the ceramic discs wear or crack, or when seals around the cartridge deteriorate.

Signs of Cartridge Problems:

• • Dripping from spout on quarter-turn taps
• • Difficulty turning tap smoothly
• • Grinding or clicking sounds when operating
• • Water leaking from handle area

5. Loose or Damaged Parts

Over time, the various components inside taps can work loose, particularly in frequently used taps like kitchen sinks.

Common Loose Part Issues:

• • Loose packing nut (leak around handle)
• • Loose adjusting ring (leak at base)
• • Damaged tap seat washer
• • Worn tap body threads

6. High Water Pressure

Excessive water pressure (over 500 kPa) can cause taps to leak by stressing washers, seals, and internal components.

Signs of High Pressure Issues:

• • Multiple taps leaking simultaneously
• • Leaks occur intermittently or at certain times of day
• • Loud banging sounds in pipes (water hammer)
• • Washers and seals fail frequently despite replacement

Universal Steps (All Tap Types)

Fixing Compression (Traditional) Taps

These are the easiest taps to repair and the most common in NZ homes. The repair typically involves replacing a worn washer.

Step-by-Step:

1. 1. Remove tap handle by unscrewing the screw under the decorative cap
2. 2. Use an adjustable wrench to unscrew the headgear/bonnet nut (the large hexagonal fitting)
3. 3. Remove the jumper valve—the washer is usually attached to the bottom
4. 4. Remove the old washer (may be held by a small nut—use pliers if needed)
5. 5. Replace with new washer of the same size (usually 12mm or 15mm in NZ)
6. 6. Inspect the valve seat for corrosion—smooth with fine sandpaper if rough
7. 7. Reassemble in reverse order

Fixing Mixer Taps with Ceramic Disc Cartridges

Modern mixer taps use cartridges that control water flow and temperature. When they fail, the entire cartridge usually needs replacement.

Step-by-Step:

1. 1. Remove lever handle by loosening grub screw (usually requires Allen key)
2. 2. Unscrew decorative cover/cap (may be threaded or just lift off)
3. 3. Use wrench to unscrew cartridge retaining nut
4. 4. Pull out old cartridge—note the orientation (often has flat sides for alignment)
5. 5. Clean the cartridge cavity, removing any debris or mineral buildup
6. 6. Insert new cartridge in same orientation as old one
7. 7. Replace retaining nut—hand-tighten then snug with wrench
8. 8. Test before fully reassembling—ensure hot/cold sides are correct
9. 9. Replace cover and handle

Fixing Leaks at Tap Base (Spout Leaks)

If water leaks from around the base of the spout (not from the spout itself), the issue is usually worn O-rings where the spout connects to the body.

Step-by-Step:

1. 1. Turn off water supply
2. 2. Look for a grub screw holding the spout—usually at the back near the base
3. 3. Loosen grub screw and lift spout straight up (may need gentle twisting)
4. 4. You'll see one or more O-rings around the spout base
5. 5. Note O-ring sizes and positions
6. 6. Remove old O-rings (use small screwdriver if needed)
7. 7. Clean the area thoroughly
8. 8. Install new O-rings in the same positions
9. 9. Apply silicone grease to O-rings
10. 10. Reinstall spout and tighten grub screw

Fixing Quarter-Turn Ceramic Disc Taps

These modern taps typically require ceramic disc cartridge replacement when they leak. The process is similar to mixer taps but simpler as they usually have separate hot and cold sides.

Quick Process:

1. 1. Remove handle (usually a small screw under decorative cap)
2. 2. Unscrew cartridge retaining nut
3. 3. Replace ceramic disc cartridge
4. 4. Ensure correct orientation when installing
5. 5. Reassemble and test

Regular Maintenance Tips

• ✓
  Don't overtighten: Closing taps with excessive force accelerates washer and seal wear. Close until water stops—no need to force it.
• ✓
  Address drips immediately: Small drips worsen quickly. Fix them before they damage valve seats or become major leaks.
• ✓
  Clean aerators regularly: Unscrew and clean tap aerators (the screen at the spout) every 3-6 months to remove mineral buildup and debris.
• ✓
  Check for loose parts: Quarterly, test all tap handles for tightness. Tighten any loose components before they cause problems.
• ✓
  Install pressure regulator: If your water pressure exceeds 500 kPa, install a pressure reducing valve. High pressure shortens tap life significantly.

Protecting Taps from Hard Water

New Zealand has varying water hardness by region. Hard water deposits (limescale) can damage taps and reduce their lifespan.

Hard Water Protection:

• • Wipe taps dry after use to prevent mineral deposit buildup
• • Clean with white vinegar monthly to dissolve limescale
• • Consider inline water filters for areas with very hard water
• • Use gentle cleaners—harsh chemicals damage finishes and seals
• • For chrome taps, use car wax occasionally for protection

Choosing Quality Taps for Longevity

When replacing taps, quality matters. Investing in better taps reduces long-term maintenance.

What to Look For:

• • Ceramic disc mechanisms: More durable than traditional washers
• • Brass bodies: Corrosion-resistant and long-lasting
• • Quality brand with local support: Easier to find replacement parts
• • WELS-rated taps: Water efficient and usually better quality
• • Good warranty: 5+ years indicates manufacturer confidence

Winter Considerations for NZ Homes

In colder NZ regions (Central Otago, Canterbury, Southland), cold weather can affect outdoor taps and exposed plumbing.

Cold Weather Protection:

• • Install frost-free outdoor taps in cold areas
• • Disconnect garden hoses in winter
• • Insulate external taps with foam covers
• • Let taps drip slightly during extreme cold to prevent freezing
• • Know how to shut off outdoor water supply before winter

Why does my tap still drip after replacing the washer?

If a new washer doesn't stop the drip, the valve seat is likely damaged or corroded. The valve seat is the metal surface the washer presses against. Over time, mineral deposits and corrosion create rough spots preventing proper sealing. You can try smoothing the valve seat with fine sandpaper, use a valve seat dresser tool, or have a plumber replace the valve seat.

How long do tap washers typically last?

Tap washers in compression taps typically last 1-5 years depending on water quality, usage frequency, and water pressure. Hot water taps wear faster due to heat. Modern ceramic disc cartridges can last 10-20 years with proper maintenance. Signs of wear include increased dripping, needing to close taps tighter, and visible deterioration when inspected.

Can I use any washer or do I need specific sizes?

Washers must be the correct size for your tap. Common NZ sizes are 12mm and 15mm diameter. Using incorrect sizes causes leaks and may damage the tap. Take the old washer to your hardware store for exact matching, or purchase an assorted washer kit ($5-10) containing multiple sizes. Most kits include both flat and conical washers suitable for various tap types.

My mixer tap leaks from the base—is this serious?

Base leaks in mixer taps usually indicate worn O-rings around the spout connection. While not immediately serious, these leaks worsen over time and can damage cabinetry underneath. They're relatively simple to fix—just remove the spout, replace the O-rings ($5-10), and reassemble. If caught early, this takes 20-30 minutes. If ignored, water damage to cabinets can cost hundreds to repair.

Should I replace or repair an old tap?

If the tap body is in good condition and parts are available, repair is usually cost-effective ($10-80 for parts). However, consider replacement if: the tap is over 15 years old and showing multiple problems, the body is corroded or damaged, you can't find replacement parts, you want better water efficiency, or repairs would cost more than 50% of replacement. Quality new mixer taps start around $80-150, while premium models cost $200-500+.

What's the difference between hot and cold tap washers?

Technically, washers are the same, but hot water taps wear washers faster due to heat causing rubber to harden and deteriorate more quickly. Some plumbers recommend using slightly thicker washers in hot taps for longer life. Always replace hot and cold washers at the same time if repairing a dual-tap system, as the cold side likely needs it soon anyway.

Can I fix a tap without turning off the main water supply?

Yes, if your tap has an isolation valve (small valve on the water pipe under the sink). Turn this clockwise to close it, and you can work on that specific tap without affecting other fixtures. However, if there's no isolation valve, you must turn off water at the mains. Never attempt tap repairs without turning off water supply—you'll flood the area instantly when you remove components.

How can I tell if I need to replace the whole tap?

Replace the tap if: you can't find replacement parts (discontinued models), the tap body is cracked or severely corroded, threads are stripped making reassembly impossible, there are multiple simultaneous problems (handle loose, body leaking, spout dripping), or repair costs approach replacement costs. Also consider replacement if the tap is outdated, inefficient, or no longer matches your décor.