Find the meter
Scarborough meters usually sit low on the street-side basement wall beside the main valve. In condos, it may be in a utility closet.
The overnight test
- Make sure nobody will use water for a few hours.
- Turn off all taps, the dishwasher and the washing machine.
- Write down the meter reading or take a photo.
- Wait two or three hours.
- Read the meter again. Any change means water is going somewhere.
Leak indicator: Look for the tiny red triangle or star wheel on the meter face; it turns whenever water moves. If it moves with everything off, there is a leak.
Where leaks usually hide
- Running toilets
- Dripping taps and shower heads
- Water softener or humidifier lines
- Outdoor taps in spring
- Pipes inside walls or under slabs
Narrowing it down
Isolate each toilet in turn with its valve and keep an eye on the meter. If it stops, you have found the culprit.
When to call
If you cannot find it, book leak detection.