Order summary
A hidden leak shows itself through the meter, through your senses, and through the building. The water meter is the most reliable test, because it measures what leaves the system whether you see it or not. Smells, stains, warm floors and swollen trim fill in where the leak might be. Check the meter first, then walk the house with a flashlight.
Numbered steps
- Turn off all taps plus any water-using appliance; remember the fridge ice maker and any softener.
- Read the meter and note the small low-flow indicator.
- Leave everything off for half an hour, using water and read again.
- If the reading moved, close the valves under toilets one at a time to see if one is the cause.
- Walk the house: look under sinks, behind toilets, around the water heater and at ceilings below bathrooms.
- Feel floors over slab areas for warm spots that could be a hot water leak.
Plumber's tip: Add some food colouring to each toilet tank. If colour appears showing in the bowl with no flush means a leaky flapper.
Errors we see on site
- Painting over a stain without finding its source.
- Blaming a high bill on the utility without testing.
- Ignoring a musty smell in a closet or cabinet.
- Waiting until the stain spreads before acting.
When the desk should come out
Call us when the meter creeps and the cause stays hidden, or when a stain keeps growing. Our water heater repair page covers tank leaks, and leak detection covers tracing. For drain-side smells, our kitchen drain leaflet may help.
Quick checklist
- Read the water meter with everything off
- Look for stains and bubbling paint
- Smell for must under sinks
Your questions on this one
Can a leak raise my bill without any visible water?
It can. A toilet that keeps refilling quietly burns through litres every hour.