Leak Detection in Penrith & Western Sydney
A water bill that jumped with nothing changed. A patch of lawn that stays green through a dry spell. A wall that feels damp on one side. There is a test you can run yourself in twenty minutes that tells you whether you have a leak at all, and it is the same test we start with. If you do have one, Sydney Water may put some of the bill back.
The meter test.
This is the single most useful thing you can do, and it costs nothing. It answers the only question that matters at this stage: is water leaving the system when nothing is using it?
Turn off every tap and water-using appliance, read the meter, wait two hours without using any water, then read it again. If the number moved, you have a leak.
Most meters also carry a small leak indicator, a little triangular or star-shaped dial that spins on very low flow. If everything in the house is off and that dial is still turning, water is escaping somewhere, and you do not need to wait two hours to know it.
Do the test overnight if you can. Nobody flushes a toilet at 2am, so an overnight reading is the cleanest one you will get.
Turn everything off.
Every tap inside and out, the dishwasher, the washing machine, the ice maker, and any irrigation timer. If you have an evaporative cooler on the roof, that counts too. Anything that can call for water on its own has to be off, or the test tells you nothing.
Read the meter and photograph it.
Write down every digit, including the black and the red ones. Photograph it with your phone so there is no argument later about what it said. Check the leak indicator dial at the same time.
Wait, and use nothing.
Two hours minimum, overnight is better. No toilets, no taps, no washing. If someone in the house uses water during the test you have to start again, so tell them it is running.
Read it again.
A different number means water left the system with nothing switched on. That is a leak, and it is on your side of the meter, which makes it yours. The same number means your usage is going somewhere visible, and the bill is worth querying with Sydney Water instead.
Keep both readings.
Those two photographs are the start of a hidden leak allowance claim. Do not delete them once the leak is fixed, because that is exactly when you will need them.
Concealed leaks announce themselves badly.
Almost never as water on the floor. Usually as one of these, and usually months before anyone connects it to plumbing.
The bill jumped
Nothing changed at home, nobody moved in, no new appliance, and the usage figure is well above the same quarter last year. This is the most common way a slab leak gets found, and often the only symptom for a long time.
A warm or damp patch on the floor
A hot water line under a slab warms the floor above it. If one section of tile or timber is warm underfoot and the rest is not, that is worth a look. Damp without warmth points at a cold line instead.
Grass that stays green
A strip of lawn or one garden bed thriving through a dry spell, often in a line. Underground supply runs in straight lines, and so does the leak that follows one.
Pressure that dropped away
Gradual loss of pressure across the whole house rather than at one tap. Low pressure has other causes entirely, so this one on its own is weak evidence. Paired with a meter that moves overnight, it is strong.
A musty smell with no visible water
Behind a wall, under a vanity, or in a cupboard against an external wall. Your nose finds this one before your eyes do, and it usually means the leak has been running a while.
Paint or skirting lifting
Bubbling paint, a skirting board pulling away, or a cornice stain that keeps returning after it is painted over. Water is arriving there from somewhere, and where it arrives is rarely where it escaped.
How Our Leak Detection Process Works
Worth being straight about this, because a lot of leak detection marketing implies a machine that points at the spot. It is more methodical than that, and the method matters more than the gear.
Australian homes are not plumbed off a manifold that zones the house, so there is no valve to close that isolates a wing of the building and narrows the search. That approach appears in a lot of overseas advice and it does not apply here.
What works is elimination. We check every fixture and fitting connected to the supply, watch how the meter responds as each is isolated, and only then bring out acoustic and thermal equipment to pinpoint what the elimination has already narrowed down. The gear confirms the location. The method finds it.
Confirm there is a leak.
We repeat the meter test properly, with a known start and end, so we are not chasing something that turns out to be a misread bill or a toilet that was running during your test.
Separate supply from waste.
A supply leak runs constantly and moves the meter. A waste leak only appears when something drains, and the meter never sees it. Two different investigations, and knowing which one you have saves hours.
Eliminate fixture by fixture.
Every tap, toilet, hot water unit, outside tap, irrigation line and appliance connection, isolated in turn where it can be, with the meter watched each time. Toilets are the most common culprit and the easiest to miss, because a slow cistern leak is silent.
Pinpoint with the right gear.
Acoustic listening equipment on a pressurised line, thermal imaging where a hot water line is involved, and pressure testing to prove a section in or out. By this point we are confirming a location, not searching a house.
Report before anyone cuts.
You get told where it is, how confident we are, what access is needed and what the repair involves, before a tile comes up or a wall is opened. Then you decide.
Sometimes it is not a plumbing leak at all.
A leaking shower or a wet wall in a bathroom is one of two things: a failed waterproofing membrane, or a leaking pipe. They present identically. On a slab home a damp wall beside a shower is either the membrane or a pipe in the wall. In a two-storey home a wet ceiling under a bathroom is a broken waste pipe, the membrane, or a water pipe.
We find which one it is, and we tell you either way. Waterproofing is not our trade. If the membrane has failed, that is a waterproofer’s job, and we will say so and point you to one rather than opening a wall looking for a pipe problem that is not there. Knowing which trade you need is most of the value of the investigation.
Sydney Water may put some of that bill back.
Very few people know this exists, and it is worth real money on a leak that ran for a quarter before anyone noticed.
Sydney Water operates a hidden leak allowance for concealed leaks that a licensed plumber has found and repaired. It is applied against your bill, so it reduces what you owe for water that leaked away rather than paying you out.
The conditions are Sydney Water’s and they set and revise them, so check the current criteria on their page before you count on it. What stays consistent is what they want to see: evidence the leak was genuinely concealed rather than something visible that was ignored, and documentation from a licensed plumber showing what was found and what was repaired. Keep the meter photographs from your own test as well.
We provide that documentation as a matter of course on every leak we repair, because it costs us nothing and it is often worth more to you than the invoice.
Frequently Asked Questions: Leak Detection & Water Bills
Direct answers from a licensed Penrith plumber. If your question is not here, send it through and we will add it.
How do I know if I have a hidden water leak?
Does leak detection cost money even if you find nothing?
Can you find a leak under a concrete slab without digging it up?
My toilet is not running. Could it still be leaking?
Will Sydney Water refund a high bill caused by a leak?
My shower leaks into the next room. Is that a pipe?
The wet patch is in the hallway. Is the leak in the hallway?
- Sydney Water · Hidden leak allowance — the allowance for concealed leaks found and repaired by a licensed plumber, and its current criteria.
- Sydney Water · Reading your meter — how to read the meter and what the leak indicator dial does.
- NSW Government · Plumbing, draining and gasfitting licences — the licensing requirement the allowance depends on.
Book a Leak Detection Inspection in Penrith
Run the meter test first, then ring the workshop with both numbers and roughly how long the gap was. That one piece of information changes what we bring and how long the investigation takes.