Signs of a hidden leak
- Your water meter moves while every tap and appliance is off.
- Damp patches, bubbling paint or mould that keeps coming back.
- The sound of running water when nothing should be on.
- A strip of lawn that stays green or soggy in dry weather.
- Hot water running out sooner than it used to.
- Pressure that has dropped slowly over weeks.
Do the meter test yourself
Turn everything off
Check that no taps, toilets, washing machine, dishwasher or irrigation are running.
Read the meter
If your property has a water meter, write down the reading or take a photo of it.
Wait without using water
Leave everything off for a good while. Overnight works if the household can manage it.
Read it again
If the number has moved, water is going somewhere. Our leak check tool takes you through it step by step.
Rule out the toilets
Close the valve to each toilet cistern, if it has one, and repeat. A cistern that never quite stops filling is a common, visible culprit.
What a leak specialist will do
A plumber who specialises in leaks starts with simple tests, then narrows down the spot before opening anything up. Depending on the house, that can mean pressure-testing sections of pipe, listening equipment, moisture readings or a thermal camera.
Once it's found, they'll tell you what has to be opened up and whether a repair will do or a run of pipe needs replacing. Ask for photos of the leak and the repair: they help with your insurer and with anyone who makes good the wall or floor afterwards.
Your pipe or the water provider's?
Each water provider draws the line in its own place, so check yours before you pay to dig.
Watercare puts Auckland's point of supply at the outlet of the meter, and everything on your side is yours to maintain. Christchurch City Council puts it at the boundary, not at the connection box, even though the council owns the toby box itself. New Plymouth District Council fixes leaks on the road side of the meter or toby, and owners fix the property side. Whangārei District Council says leaks on your own property are yours.
In the Wellington region, Tiaki Wai notes that council bylaws differ slightly, so ask rather than assume.
What changes the job
Access drives most of it. A leak under a concrete slab, inside a tiled wall or beneath paving takes more finding and more making good than one in a ceiling space. The pipe material and its age matter, as does how long the run is and whether it's the hot or cold side.
The rules for the repair
Fixing or replacing water supply pipes inside your boundary is sanitary plumbing, which only an authorised person may do. Repairing plumbing with comparable products, or replacing it in the same position, needs no building consent when an authorised plumber does the work, though it must still meet the Building Code.
The Code itself asks for water systems installed to avoid the likelihood of leakage and to allow reasonable access to parts that are likely to need maintenance.
Since 2 May 2026, new plumbing products in drinking-water systems have had to meet lead-free requirements. That covers new work only; the pipes already in your walls haven't become non-compliant overnight.
What you can do, and what to hand over
You can
- Run the meter test and note the readings.
- Replace a dripping tap's washer: repairing taps is on PGDB's homeowner list.
- Swap a faulty ball cock in a toilet cistern, which is on the same list.
- Photograph damp patches as they change.
Leave to an authorised tradie
- Cutting into walls, floors or ground to reach a pipe.
- Repairing or replacing any water supply pipe.
- Leaks from a hot water cylinder or its valves.
- Pressure-testing the pipework after the repair.
Questions to ask the plumber
- How will you pinpoint the leak before opening anything up?
- Is this a quote or an estimate?
- Will you show me the leak, with photos, before you repair it?
- Is the fault on my side of the point of supply?
- What will need opening up, and who puts it back afterwards?
What we would do
Start with the meter test, because it tells you whether there is a leak at all. If there is, pay for finding it properly before anyone cuts holes; a guess can mean opening up the wrong wall and paying twice. Tell us what you've noticed and what the meter did, and we'll pass it to a plumber who specialises in tracking down hidden leaks.