Rule out the obvious
Before hunting for a leak, check whether anything changed. A visit from relatives, a new lawn being watered, a pool fill, or a billing period that ran longer than usual can all raise a bill. Compare the consumption figure, not just the dollar amount, against the same season last year. Water and sewer rates change periodically too.
Meter test
The water meter records every litre that enters the house, so it is the honest witness. Most meters carry a tiny leak dial, usually a red triangle or star, that turns with the faintest draw.
- Make sure no one uses water, and that the dishwasher, washing machine, softener and irrigation are idle.
- Look at the low-flow indicator. If it is moving, water is flowing somewhere.
- For a longer test, write down the whole meter number, leave every fixture alone for an hour or two, then compare.
- If the number has changed, there is a leak.
- Shut the little stops behind every toilet, then do the reading again. If the meter stops, a toilet is the cause.
Toilet dye test
Running toilets are the leading cause of unexplained high bills. A worn flapper lets tank water seep into the bowl, often with no sound at all. Take off the tank lid and tint what is in the tank with food colouring. Wait fifteen minutes without flushing. Tinted water showing up in the bowl, the flapper is leaking. A worn flapper, a chain that is too short, or a fill valve set too high are the usual culprits. Our note on the running toilet walks through the fixes.
Outdoor lines
Hose bibs, underground irrigation and lines to detached garages hide leaks well. A frost-free faucet that split last winter may only leak when the hose is turned on, sending water into the wall or foundation. Irrigation zones can leak underground at a fitting or a damaged head. Look for unusually green or soft patches of lawn, a sinking spot in the yard, or water pooling where it should not.
- Run each outdoor tap and look inside the basement wall at the same time.
- Run each irrigation zone and walk the lawn.
- Check the water softener, which can stick in regeneration and drain water continuously.
When to call
If the meter shows flow and the toilets and outdoor lines are ruled out, the leak may be under a slab, in a wall or on the service line. Our leak detection service locates it without guesswork. Water reaching the basement may also need our basement flooding help. Freezing damage often hides in exterior walls, covered in our note on frozen pipes.
Asked on the phone
Is a running toilet enough to push my bill up?
A toilet that never stops refilling can pour a startling volume down the drain between bills. It is often the single biggest hidden cause.
Who do I contact about a billing error?
Your water billing is handled through the municipality. Contact them with your meter readings if the numbers look wrong.
Can a leak be on the town's side?
Yes. A leak on the street side of the curb stop belongs to the municipality.