Running toilet, dripping tap: when it's a 10-minute fix

A running toilet can waste over 25,000 litres in a single quarter. That's a real water bill. The good news: most running toilets and dripping taps in Eastern Suburbs homes are a 10 to 15 minute DIY fix, with $20 in parts from the hardware store. The catch is the small percentage that aren't, and trying to DIY those tends to make things worse before a plumber sees them. Here's how to tell which one you're dealing with before you start.

Why a running toilet wastes so much water

A toilet that runs constantly is letting clean water escape from the cistern into the bowl all day, every day. At a typical fill rate, that's 200 to 600 litres per hour. Even a quiet leak that you can only just hear is usually wasting 10,000-25,000 litres per quarter. You'll see it on your Sydney Water bill before you see it anywhere else.

The other failure mode is phantom flushing, where the cistern refills on its own every 20-30 minutes even though nobody's used it. Same root cause, slower bleed, same answer.

The 10-minute fixes

These are the ones you can do yourself before calling anyone:

• Worn flapper or flush valve seal. The most common cause. The rubber flap at the bottom of the cistern that lifts when you flush and drops back to seal it has hardened or warped, so it no longer seats properly. A replacement flapper is $10-$25 at any hardware store, takes about 10 minutes to swap, and fixes 60-70% of running toilets we see in Eastern Suburbs homes.
• Failed inlet/fill valve. The mechanism that refills the cistern after a flush has worn out and won't shut off. Looks like a vertical column with a float on top. Universal replacement valves are $20-$40 and around 15 minutes to swap if you have basic tools.
• Tap washer (for a steadily dripping tap). Most non-mixer taps still use a rubber washer that wears out every 5-10 years. A pack of washers is under $10. The job is: turn off the water at the mains, unscrew the tap bonnet, swap the washer, screw it back together. 10 minutes if you've done it before, 20 if you haven't.
• Mixer tap cartridge. If your tap is a single-handle mixer and it's dripping, the ceramic cartridge inside has failed. Replacement cartridges are $30-$80 depending on brand. Trickier than a washer swap but still DIY-friendly if you can match the cartridge to the tap brand.

When it's not a DIY fix

A small share of cases need a licensed plumber. Get one if you see any of these:

• The tap or toilet is leaking from anywhere other than the spout or bowl. Leaks at the base of a tap, around the wall flange, or under the toilet pan are not washer or flapper problems. They're seal or pipe problems behind the wall, and a DIY attempt usually makes them worse.
• You've replaced the washer twice and it's still dripping. Means the tap seat itself is corroded and needs reseating - a specific tool that most homeowners don't own. Cheap to fix if a plumber does it; expensive if you DIY and the tap body cracks.
• The cistern is leaking from the tank itself, not the inlet. Hairline crack in the cistern body. Rare but it happens, and the answer is usually a new cistern.
• Banging or vibrating pipes when the cistern refills. Water hammer, which means a worn valve or unsecured pipework somewhere upstream. Replacing the inlet valve sometimes fixes it; sometimes the issue is elsewhere.
• Brown or rusty water from the tap that won't clear. Internal pipe corrosion, especially common in pre-1985 Eastern Suburbs homes with original copper pipework. Not a tap repair - it's a leak detection or repipe conversation.

Dripping tap, same logic

A dripping tap follows the same pattern as a running toilet. Most are a $5 washer or a $50 cartridge swap, take 10-20 minutes, and stay fixed for years. The few that aren't usually involve a corroded tap seat, a damaged spindle, or a leak inside the wall - and those are the ones where a 30-minute callout saves you a $2,000 bathroom water-damage repair down the line.

If you've made an honest DIY attempt and the drip's still there, that's the signal. Stop and call.

How to reach Norton Plumbing

Norton Plumbing operates from 10/11a-15 Berwick Street, Coogee NSW 2034. Phone: 0477 858 951. We can reach most of the Eastern Suburbs in under 20 minutes including Bondi, Bronte, Randwick, and Maroubra. We are available 24/7 for emergencies, and during business hours there is no callout fee. I'm Adam Norton, NSW plumbing licence 397768C. I attend most Eastern Suburbs jobs personally, otherwise it'll be Blake or another licensed plumber from the Norton Plumbing team. If you'd rather see what we cover before you call, our tap and toilet repair page walks through the work in detail.