How to find a water leak at home: the meter test, where to look, and when to call a plumber

Signs you may have a hidden leak

A hidden leak usually shows up as something you can measure or hear, not water you can see. Look out for these signs:

• A water bill that’s higher than the same quarter last year, with no change in how your household uses water.
• The sound of running water, or a toilet refilling, when nothing is turned on. Logan City Council says the sound of a toilet constantly filling is one sign of a leak.
• A damp patch, stain, mould or bubbling paint on a wall or ceiling.
• A soggy or unusually green strip of lawn during dry weather.
• A damp or warm spot on a tiled or concrete floor.
• Water pressure that has dropped for no clear reason. Our guide to low water pressure causes covers the other possibilities.

Don’t wait for the bill to tell you. Redland City Council reads water meters four times a year, and notes that many homeowners only learn they have a concealed leak after the meter has been read. Reading the meter yourself gives you an answer today.

The water meter test, step by step

The water meter test tells you whether water is leaving your pipes when nothing should be running. These steps follow the checks Logan and Redland councils publish:

1. Find your meter. In the Redlands it’s generally on or near the street boundary (Redland City Council). Logan residents can ask council on 3412 3412.
2. Wear gloves and lift the box lid carefully. Logan’s fact sheet warns meter boxes can hide spiders and snakes.
3. Turn off all taps, water-using appliances and the irrigation. Leave the meter’s stop tap on.
4. Look at the dials. On Redland meters the black numbers are kilolitres, the circular dials are litres, and the small centre dial is a leak detector that spins whenever water is used.
5. If nothing moves, photograph the reading, wait at least an hour without using water, and read it again.
6. If the reading has changed, there could be a leak, and Logan City Council says to call a licensed plumber to find and repair it.

If you don’t want to wait for your next bill, Your Home suggests photographing the meter before bed and comparing it to the reading first thing in the morning.

Leak before the house or inside it? Close one section at a time

Closing off one part of the plumbing at a time tells you whether the leak is on the pipe to the house or inside it. Recheck the leak-detector dial after each step:

1. Close the stop tap on each toilet, usually beside or behind the pan. If the dial stops, a cistern is leaking.
2. Close the cold water isolation valve going into the hot water system. If the dial stops, the leak is in the hot water system or hot pipes. Leave its other valves alone.
3. Turn off the irrigation at its own tap or valve, and close any outdoor taps with their own isolation valve.
4. If your house has a main isolation valve where the supply enters the building, close it. If the meter still moves, the leak is between the meter and the house.

A leak between the meter and the house is often underground or under the slab, the kind water providers call a concealed leak. Don’t dig for it, as other services can be buried nearby. Note what you found, open every valve again, and tell your plumber. If water is pouring out, go straight to our burst pipe guide.

Where to look: a room-by-room and yard checklist

The first places to check are the fittings that use water all day without anyone watching them: toilets, taps, the hot water system and the irrigation.

• Toilets: put a few drops of dark food colouring in the cistern and don’t flush. Logan City Council says to check the bowl after 20 to 30 minutes; colour there means a leak. Test every toilet. Your Home says a slow, barely visible toilet leak can waste more than 4,000 L a year.
• Taps and showers: watch for drips. Your Home says one drip a second wastes more than 12,000 L of water a year.
• Under sinks and vanities: damp or swollen cabinet floors, and flexible hoses that are rusty, frayed or bulging.
• Hot water system: water pooling at the base or running from the drain pipe. Look only, and don’t touch the relief or tempering valves. See our guide to a hot water system leaking.
• Walls and ceilings: stains, bubbling paint or a musty smell, especially behind a shower wall.
• Slab floors: damp or warm patches, or lifted tiles.
• Garden: soggy ground in dry weather, a dip along the supply pipe, or sprinklers that keep weeping.

What your symptom can point to, and when to stop and call

Matching what you can see to its likely cause tells you which safe check to try, and where the job becomes a plumber’s. Treat the table as a guide to where to look, not a diagnosis.

Leak at the meter or in the street: the water provider’s job

Your water provider looks after its supply network, and you, as the property owner, look after the pipes on your side of the meter. Who to call depends on where you live:

Sources: Redland, Logan and the Urban Utilities customer charter. A leak on the house side, including the buried pipe from the meter to the house, needs a licensed plumber. Urban Utilities also asks owners to keep the meter clear of obstructions such as garden beds.

High water bill with no visible leak: check these first, then ask about relief

A high water bill with no visible leak has a short list of causes, and the meter test separates a leak from the rest. Redland City Council’s fact sheet lists:

• High use during the period, such as filling a pool or a lot of hosing.
• A leak, which may be underground and out of sight.
• Other plumbing issues, such as a running toilet or washing machine.
• A faulty top-up system on a water tank or pool.
• A misread water meter.
• More people in the house, such as visitors staying.

If a licensed plumber repairs a hidden leak on your side of the meter, your provider may reduce the bill under its concealed leak scheme. Leaks from fittings and appliances, inside or outside the house, are generally not covered: Urban Utilities’ policy, for example, excludes taps, toilets, hot water systems, sprinklers and irrigation.

Logan’s conditions are on its concealed leak remissions page. The clock starts when you find the leak, so book the repair quickly and ask your plumber for the paperwork your provider needs.

How plumbers find leaks you can’t see, and what you can legally fix in Queensland

A plumber finds a leak you can’t see by narrowing the search, then using specialist equipment to find the leak and mark its location. Sydney Water describes its qualified specialist plumbers using pipe location devices, acoustic listening devices and techniques such as filling pipes with a safe gas to find any concealed leak and mark its location.

Queensland law limits what you can fix yourself. The QBCC says all regulated plumbing and drainage work must be done by an appropriately licensed person, and that includes replacing a tap. The Queensland Government says the water plumbing you can do yourself includes replacing a jumper valve or washer in a tap, changing a shower head, and replacing a drop valve washer, float valve washer or suction cup rubber in a toilet cistern.

You can check any plumber’s licence online or with the QBCC on 139 333. Jim Monger Plumbing and Gas holds QBCC licence 15504687, is based in Victoria Point, and handles burst pipes and leak detection as well as hot water systems in Victoria Point. Call 0418 871 269 and tell us what your meter test showed.