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Quick Answer

A leaking tap usually needs a new washer, which you can replace in 10 minutes for $2-5. Turn off water, unscrew the tap handle, pop out the old washer, insert the new one. Done.

What You’ll Need

Tools & Materials:

  1. Adjustable wrench ($12-20 at Bunnings)
  2. Screwdrivers—flat and Phillips ($8-15 at Mitre 10)
  3. Replacement tap washers assorted pack ($3-8 at Reece)
  4. Tap seat dressing compound optional ($5-10 at local hardware)
  5. Plumber’s grease ($4-8 at Bunnings)
  6. Cloth or old towel (for grip and water absorption)
  7. Container to catch water drips

Why Tap Washers Wear Out

Tap washers are the unsung heroes of your plumbing. These small rubber discs seal your tap when it’s off, preventing drips. After 3-5 years of daily use, SE Melbourne’s hard water minerals erode the rubber, causing the classic slow drip.

A dripping tap isn’t just annoying—it wastes 20+ litres per week. That’s $2-3 monthly on your water bill, plus it stains your sink. The fix is laughably easy: pop out the worn washer, slide in a new one ($2-5), and you’re done. Many locals in suburbs like Hawthorn and Toorak do this themselves every 4-5 years without thinking twice.

If you don’t want to replace the washer yourself, a plumber charges $80-120 for a 10-minute job. DIY is the obvious choice here.

Step-by-Step Guide

Turning off isolation tap under bathroom sink
Locating and turning off the isolation tap under the sink before starting tap washer replacement — this is the most important step to prevent water spraying everywhere when the bonnet is removed.
  1. Open the tap fully and let any remaining water drain out. Place a container or cloth underneath to catch drips.
Removing tap cap with screwdriver
Popping off the decorative cap on a tap handle to reveal the retaining screw underneath — a flat screwdriver slots into the edge without scratching the tap finish.
  1. Unscrew this screw (usually just 2-3 turns) and remove the tap handle. It should lift straight off.
  2. Under the handle, you’ll see a large hexagonal nut called the ‘tap cover’ or ‘bonnet’. Unscrew this with your adjustable wrench by turning counter-clockwise. Keep the cloth under the tap to catch any water.
Comparing old worn tap washer with new replacement
Old worn tap washer alongside a matching new replacement — sizing matters, a washer that is even 1mm too small will not seal and the drip will return within days.
  1. Insert the new washer of the same size. If unsure, take the old washer to Reece and match it. Most taps use 12mm or 16mm washers. It should click into place snugly.
  2. Screw the bonnet back on hand-tight, reinstall the handle, pop the cap back on, and tighten the screw. Turn the water back on and test. The tap should shut off cleanly with no drip.

Troubleshooting

ProblemCauseSolution
Tap still drips after new washerTap seat is damaged or scoredRemove old washer, inspect the seat (metal ring inside). If pitted, rub with tap seat dressing compound or call plumber for seat replacement
Can’t unscrew the bonnetOver-tightened or corrodedSpray with penetrating oil (WD-40), wait 10 minutes, try again. Don’t force—you’ll crack the tap
Water sprays from under the bonnetBonnet not tightened properlyTurn off water, retighten bonnet hand-tight plus one-quarter turn. Avoid over-tightening
New washer pops out immediatelyWrong size or installed upside downRemove, check size matches old washer. Reinstall rounded side up. If too small, tap won’t seal—size up
Handle is loose after reassemblyScrew under cap not tight enoughPop the cap off again, tighten the screw under the handle. Should be snug but not over-tight

When to Call a Professional

Call a plumber if: the tap seat is damaged (requires professional grinding or replacement), the bonnet is seized and won’t budge even with penetrating oil, the tap body is cracked, or you’re uncomfortable taking the tap apart. A plumber’s call-out costs $80-120, but it’s worth it if you damage the tap yourself.

Tips & Gotchas

  1. Safety note: Turn off the water FIRST. If you forget and unscrew the bonnet, water will spray everywhere and flood your cabinet.
  2. Keep the pieces in order as you remove them. It’s easy to forget which way the washer goes back in. Lay them on a clean cloth in sequence.
  3. The washer should be rounded-side up when reinstalled. If it’s flat-side up, it won’t seal properly and you’ll have a wasted 10 minutes.
  4. SE Melbourne’s hard water leaves mineral deposits on tap seats. If your new washer doesn’t fix the drip, the seat might be pitted. A plumber can replace it ($50-80), or you can try seat dressing compound ($5-10 at Bunnings) as a DIY fix.
  5. Buy an assorted washer pack ($3-8) from Reece. You’ll get multiple sizes and likely not need another pack for years.
  6. Don’t over-tighten the bonnet when reassembling. Hand-tight plus one-quarter turn is all you need. Over-tightening cracks the ceramic or strips threads.
  7. If you’re replacing washers on multiple taps (kitchen and bathroom), do them all in one afternoon. It’s faster and you’ll remember the technique.
  8. Keep plumber’s grease handy. A small dab on the spindle makes future disassembly easier. Hard water creates mineral buildup over time.
  9. Old taps sometimes have cartridges instead of washers. If you open yours and don’t see a rubber disc, the cartridge might need replacement. Stop and call a plumber—cartridge swaps are trickier.
  10. In rental properties, check your lease before DIY repairs. Some landlords have specific plumber requirements. It’s rarely an issue for washer replacement, but confirm first.

Frequently Asked Questions

How often do tap washers need replacing?

Every 3-5 years depending on water quality and use. SE Melbourne’s hard water can speed up wear. If your tap drips, it’s washer time.

Can I just tighten the tap to stop the drip?

Temporarily, yes. But you’ll damage the washer faster by over-tightening. Replace the washer instead—it’s $2-5 and takes 10 minutes.

What’s the difference between a 12mm and 16mm washer?

Size. The washer sits in a recessed holder inside the tap. If you install the wrong size, it won’t seal. Take your old washer to Reece to match the size.

Do all taps have the same washer type?

No. Older ceramic-disc taps use different internals than traditional rubber-washer taps. Modern lever taps often use cartridges. If your tap doesn’t have a rubber washer inside, you need a cartridge replacement—call a plumber.

Is it worth fixing an old tap or should I replace the whole tap?

Replace the washer first—costs $5 and takes 10 minutes. If the tap drips again within a few months, the seat is damaged. Then consider a full replacement ($40-100 for a decent tap).

What if I lose a piece while taking the tap apart?

Don’t panic. Keep all pieces on a clean cloth in order. If you lose a screw or small part, take what you have to a hardware store—they can often match it.

Can hard water damage a new washer quickly?

Yes, very hard water erodes rubber faster. SE Melbourne suburbs like Malvern and Toorak have harder water than outer suburbs. If washers fail every 2 years, consider a water softener ($500-1500 installed) to extend tap life.

Local Hardware & Plumbing Stores (SE Melbourne)

  • Reece Plumbing Camberwell – Full washer assortments, tap seat tools, professional advice
  • Bunnings Hawthorn – Budget washers, wrenches, screwdrivers, plumber’s grease
  • Mitre 10 Glen Waverley – Tap washers, tools, general plumbing supplies
  • Local Independent Hardware (Toorak Village) – Hard-to-find vintage washer sizes
  • Spotlight (Chadstone) – Craft supplies, but also basic tools and washers
  • Chemist Warehouse (multiple suburbs) – Quick runs for small supplies