How to tell if you have a hidden water leak
Most leaks are hidden inside walls, under floors or underground, and you often only find out when the water bill jumps. This guide covers the signs, two simple tests you can do yourself, and how we find and fix leaks without pulling your home apart. It's written by the local plumbers who track down leaks across Matraville, Maroubra, Malabar, Botany and the southern Eastern Suburbs.
Signs of a hidden leak
- Your water bill has jumped and you can't explain why
- Damp patches, stains or bubbling paint on walls or ceilings
- Mould or a musty smell
- Loose, cracked or drummy tiles in the bathroom
- The sound of running water when every tap is off
- A wet or extra-green patch of lawn
- Water pressure dropping all of a sudden
- The toilet refilling by itself
Two tests you can do yourself
1. The water meter test
Turn off every tap and water-using appliance. Write down or photograph the meter reading, don't use any water for 30 to 60 minutes, then check again. If the numbers moved, water is leaking somewhere. Turn off the main: if the meter stops, the leak is inside your property.
2. The toilet dye test
Put a few drops of food colouring in the toilet cistern, not the bowl, and don't flush for 20 minutes. If colour shows in the bowl, the cistern is leaking. A running toilet can waste a lot of water every day.
How we find and fix leaks
- Isolate: we test sections of your plumbing one at a time to narrow down where the leak is.
- Locate: pressure testing, listening equipment and thermal or moisture readings pinpoint it.
- Options: we show you what we found and give you options with a fixed price before any work.
- Repair: we fix it with the least damage possible and give you a report of what we found and fixed.
Ask about your water bill
Sydney Water may give an allowance for water lost through a hidden leak that's been repaired by a licensed plumber. Ask us for a repair report to send with your claim.
Don't leave it
A small leak under a floor or inside a wall can rot timber, damage tiles and attract termites long before you see it.
Leaks in older southern Eastern Suburbs homes
Many homes in Matraville, Maroubra, Malabar and Botany still have galvanised or early copper water pipes. Galvanised pipe rusts from the inside, and older copper can develop pinholes, especially where pressure is high. Under-floor and in-wall leaks are common in these homes, along with worn shower seals that let water into the next room. See our water pressure guide, because high pressure makes leaks more likely.
Why locals call us for leaks
- Based in Matraville, close to every southern Eastern Suburbs home
- 100+ five-star Google reviews
- We find the leak before we open up walls
- A fixed price before any work starts
- Licensed plumbers (Lic. 398171C)
Common questions
How do I know if I have a water leak?
Do the meter test: turn everything off, note the meter, and check it again after 30 to 60 minutes. If it has moved, water is escaping somewhere.
Can you find a leak without breaking walls?
Usually, yes. We use pressure testing, listening equipment and thermal or moisture readings to pinpoint it before we open anything up.
Will Sydney Water reduce my bill for a leak?
They may give an allowance for water lost through a hidden leak repaired by a licensed plumber. We can give you a repair report to send with your claim.
Do you charge to find a leak?
If we need to investigate before we can quote, we'll tell you the investigation fee before we start, so there are no surprises.
Think you have a leak? See our leak detection and burst pipe services, or your local page: Matraville, Maroubra, Malabar, Pagewood, Eastgardens, Botany and Little Bay. More plumbing guides.