Signs of a leak you can't see
- Your water bill went up and your use didn't.
- The meter moves when every tap and appliance is off.
- Bubbling paint, a stain or mould on a wall or ceiling.
- Loose tiles, lifting floorboards or a warm patch on a tiled floor.
- Running or hissing water you can hear when nothing's on.
- One patch of lawn that's greener or soggier than the rest.
Start with the meter
Turn off every tap and water-using appliance, read the meter, wait without using water, and read it again. If the numbers have moved, water is escaping somewhere past the meter.
Our meter test walks you through it, and the high water bill page covers what to do about the bill itself.
How a plumber finds it
A plumber will first confirm the leak at the meter, then shut off parts of the system one at a time to see which section is losing water. Hot or cold, inside or outside, toilets or pipes: each test rules something out.
Then come the tools. Listening equipment picks up the sound of water escaping under a slab or a path. A thermal camera shows the warm trail of a leaking hot pipe. Moisture meters map a damp wall, and a pressure test on one pipe at a time confirms which run has failed.
The aim is one small, accurate opening instead of several guesses.
Where leaks often hide
| What you might notice | Read more | |
|---|---|---|
| Toilet cistern | Ripples in the bowl, or a faint trickle long after a flush | Toilet keeps running |
| Pipe inside a wall or under a floor | Bubbling paint, swelling skirting, a musty cupboard | Leaks in walls and under the house |
| Hot water system | Water pooling around the base of the unit | Leaking hot water systems |
| Pipe between the meter and the house | A soggy or greener strip across the yard | Burst pipes |
| Swimming pool | Topping up far more often than you used to | Pool leaks |
What changes the job
How many pipes could be involved, and where they run. A leak in a timber subfloor you can crawl under is quicker to find than one under a concrete slab. Hot or cold matters, so does the pipe material, and so does whether you need a written report for an insurer or the water company.
What you can check first
You can
- Do the meter test, with the irrigation, pool top-up and evaporative cooler off too.
- Listen at each toilet for a faint hiss once the cistern has filled.
- Look under sinks, behind the washing machine and around the hot water system.
- Close the isolation valve to one toilet or appliance at a time, and watch whether the meter stops.
Leave to a licensed plumber
- Opening walls, floors or paths, and repairing the pipe inside.
- Pressure-testing pipe runs, and using listening or thermal gear.
- Rerouting a pipe that can't be reached under a slab.
- Any water supply work that isn't on your state's list of jobs homeowners may do.
Who owns the leaking pipe
Where your part starts is set by your water company, and the rules differ. Unitywater says "All water pipes and fittings from the water meter on to private property are the property owner's responsibility to maintain." The City of Gold Coast says it fixes leaks in the water supply system "up to and including your water meter."
Your water company is named on your bill. If the leak is on its side, report it to the company rather than booking a plumber.
Licences and paperwork
Finding and fixing a leak in a water pipe is plumbing work. In Victoria, plumbers are either registered or licensed for each class of work, and only licensed plumbers can issue compliance certificates. In Queensland, the QBCC says a contractor needs an occupational licence to perform plumbing work. In NSW, where a Certificate of Compliance applies, the plumber must give a copy to the person who arranged the work.
Questions to ask the plumber
- How will you find it, and how much will you need to open up?
- Will I get a written report showing where the leak was and why?
- Is the leak on my side of the meter or the water company's?
- Can you repair it on the same visit, or is that a second job?
- Will you pressure-test the pipe after the repair?
What we would do
Do the meter test before you book anyone. If the meter is still, your damp patch may be a shower, a roof or a drain rather than a water pipe, and that changes who you need. If it moves, get a plumber who specialises in finding leaks, not just fixing them: the right gear means one small hole in the right place instead of three in the wrong ones.