The entry in brief
Watch your water meter, your bill and your ceilings. A meter that moves when nothing is running is the clearest sign of a hidden leak.
The meter test
- Shut every tap and stop every machine that draws water.
- Write down the numbers, or watch the little red or black triangle on the dial.
- Wait an hour or two without using water.
- Look once more. If it moved, water is escaping.
Signs around the house
- Stains, bubbling paint or soft drywall on ceilings below bathrooms.
- Musty smells in one room or cupboard.
- Warm patches on floors over hot water lines.
- Loose tiles or cracked grout around a shower.
- Mould at the base of a wall or behind a toilet.
- A trickling sound in a silent house.
N.B. A toilet can leak silently from tank to bowl. Add food colouring to the tank and see if it appears in the bowl without flushing.
Common hidden sources
Shower valves behind tile, toilet wax seals, supply lines to dishwashers and fridges, pinholes in old copper, and failing Poly-B fittings. In condos, leaks may come from the unit above, which makes tracing harder.
What to do next
If the meter test confirms a leak, close the main valve and ring for help. Our leak detection page explains how we narrow it down without opening more walls than needed.
What callers want to know
Does a small drip really add up?
A steady drip can add up to thousands of litres a year.
Will home insurance cover a hidden leak?
Policies differ. Many cover sudden damage but not gradual leaks, so act quickly and check your policy.