How Much Does a Leaking Tap Actually Cost You?

It starts as a gentle drip. You tell yourself you’ll get to it eventually. Then weeks become months, and that tap is still dripping. It seems harmless — after all, how much water can a single drip really waste?

The answer, it turns out, is quite a lot. And the water cost is only part of the story.

The Numbers: What a Dripping Tap Actually Costs

The maths is simple once you run it:

Sydney Water charges around $2.77 per kilolitre (1,000 litres) for the first tier of usage. A hot water tap leak costs considerably more — you’re also heating all that water you’re wasting, adding to your energy bill on top of the water bill.

The Hidden Cost: Water Damage

The water bill is just the start. A leaking tap that drips onto or near a surface — timber vanities, under-sink cabinetry, tile grout — causes gradual water damage that can be far more expensive than the original repair.

Common water damage from ignored tap leaks includes:

• Timber swelling, warping or rotting under bathroom and kitchen benches
• Mould and mildew growth inside cabinets — a health risk as well as a repair cost
• Grout and silicone deterioration around the sink or basin
• Rust and corrosion on pipes and fittings
• Damage to flooring if the leak goes unnoticed for a long time

A $150 tap washer replacement today can save you $1,500+ in cabinetry repairs down the track.

Types of Tap Leaks — and What Each One Means

Dripping from the Spout

The most common type. Usually caused by a worn tap washer or O-ring. On older style taps (compression taps), it’s almost always a washer. On mixer taps, it’s typically a ceramic cartridge that needs replacing.

Leaking Around the Base of the Spout

Water pooling at the base of the tap — especially when it’s turned on — indicates a worn O-ring on the spout body. This is a straightforward fix but needs to be done before the leak damages the bench or cabinet below.

Leaking Under the Sink

If the drip is coming from the pipe connections beneath the sink, it’s likely a loose fitting, degraded thread tape, or a corroded supply line. This one needs attention quickly — it can saturate the under-sink cabinet without you noticing.

Running Toilet (Often Mistaken for a Tap)

A toilet that “runs” constantly — where you can hear water trickling into the bowl — is the most expensive leak of all. A running toilet can waste up to 60,000 litres per year. That’s roughly $165 straight off your water bill, every year, until it’s fixed.

DIY or Call a Plumber?

In NSW, you legally need a licensed plumber for most tap repairs — including replacing tap washers, cartridges, and any work involving the water supply. It’s not just a formality: incorrect repairs can void your home insurance and potentially make leaks worse.

That said, there are a couple of things you can safely do yourself:

• Tightening an aerator (the small filter at the tip of the spout) if it’s loose
• Replacing a tap cover button or decorative cap
• Tightening an accessible compression fitting under the sink (hand-tight only)

For anything that involves removing tap components, replacing washers or cartridges, or touching the water supply lines — call a licensed plumber. It’s a quick, inexpensive job for a professional.

How Much Does It Cost to Fix a Leaking Tap in Sydney?

Typical costs for leaking tap repairs in Sydney:

• Tap washer replacement: $100–$180
• Ceramic cartridge replacement: $120–$220
• O-ring replacement: $100–$160
• Under-sink supply line repair: $120–$200
• Full tap replacement (supply only): $200–$400+

Mr. Clog charges no call-out fee, and most tap repairs are completed in a single visit. Given the ongoing water and potential damage costs, getting it fixed is almost always the right financial decision.

Frequently Asked Questions