Compare the current bill with previous readings, focusing on water volume, not just the amount charged.

Check for:

Use consistent units. Your bill may show gallons, cubic meters, or kiloliters.

If your provider offers daily or hourly usage, look for water use during periods when nobody normally needs it. Continuous overnight flow can be a useful clue, although automatic equipment must be ruled out first.

Water Corporation explains that smart-meter leak alerts use patterns of continuing water flow to identify a possible problem. An alert indicates something to investigate, rather than an exact leak location.

A meter test helps identify water passing through the metered supply when you do not expect any use.

Choose a time when the household can avoid using water.

The EPA recommends comparing readings before and after a two-hour period with no water use. Do not wait for a full test if there is already active damage that needs immediate attention.

If the reading increases, water has passed through the meter. That may be a leak, but confirm that an automatic appliance did not operate.

For a digital meter, follow your utility’s instructions for reading its flow display and refresh interval.

A stationary meter does not rule out every leak. Drain leaks, rainwater entry, and intermittent leaks may not show during the test.

Empty cabinets so you can see the plumbing clearly.

Dry accessible surfaces, then inspect:

Use a dry paper towel against accessible connections to help reveal a small amount of fresh moisture.

Observe the area with the faucet off. If there is no active damage or electrical risk, run a small amount of water while watching the supply and drainage connections.

Moisture that appears only during draining points toward a different part of the system from a hose that drips continuously.

Water can also enter around a poorly sealed sink edge or faucet base.

For a visible connection leak, see our guide to fixing a leaking pipe under the sink.

Inspect accessible areas around:

Look for mineral trails, rust marks, damp flooring, and swollen cabinetry.

Do not pull a heavy appliance against attached hoses, reach behind energized wet equipment, or open service panels.

Around a water heater, moisture may come from a connection, condensate system, relief discharge, or the tank. Do not assume that every puddle means a leaking tank.

Never cap a safety-valve discharge pipe or disconnect pressurized equipment to investigate.

If an appliance leaks during use, stop operating it and arrange the appropriate repair.

Look for changes rather than relying on one stain:

Photograph affected areas and record the date. Note whether they change after rain, bathing, laundry, or other water use.

Do not assume the source is directly above the mark. Water may travel before it appears.

Avoid cutting into a damp wall or ceiling. Hidden wiring, pipes, and potentially hazardous building materials make exploratory demolition a poor first step.

For a roof or upper-story concern, arrange inspection rather than climbing onto the roof yourself.

Walk around the property during dry weather, where it is safe to do so.

Check for:

An unusually green patch of lawn may justify investigation, but shade, soil, and drainage can create similar patterns.

Do not dig along a suspected service pipe or operate utility-owned valves. Contact the water provider if you suspect its equipment or public pipework.

Responsibility boundaries differ by provider and property. Ask who owns the affected section before arranging excavation or repairs. Water Corporation, for example, distinguishes responsibilities for different meter and pipework locations.

If unexplained meter use continues, accessible homeowner-operated isolation valves may help identify an affected branch.

For example, a toilet that has finished filling can be isolated temporarily and the no-use meter check repeated. A change in unexplained consumption helps direct the investigation.

Only do this when:

Do not force old valves or disturb water-heater, fire-sprinkler, or unfamiliar system controls.

Water Corporation notes that isolation valves can assist leak investigations. They help narrow the area; they do not pinpoint a break inside a wall or underground.

A plumber can perform more controlled isolation and pressure testing when needed.

Moisture Meters

A moisture meter can help compare a suspect area with nearby material that appears dry.

Follow the tool’s instructions and use the correct setting for the material. Readings can be affected by construction materials, metal, and other conditions.

A high reading indicates a reason to investigate. It does not identify the source or prove that a supply pipe is leaking.

Avoid pushing meter pins into areas that could contain wiring or services.

Thermal Cameras

A thermal camera shows surface-temperature differences. It does not see through walls or directly confirm water.

FLIR explains that thermal patterns can suggest moisture, but further checks are needed to verify the finding.

A warm floor patch or cool wall area may be useful evidence, but neither is enough on its own to justify opening the structure.

Call a qualified plumber or leak-detection specialist when the evidence points to a concealed plumbing problem.

Depending on the suspected source, they may use:

The tool should match the problem. A drain camera can inspect a waste pipe, but it does not locate every pressurized supply leak.

Give the technician your meter readings, photographs, and symptom timeline. Ask how the suspected location will be verified before opening walls, floors, or ground.