Why Your Water Bill Suddenly Jumped

Start with the meter

Your water meter is usually in the basement close to where the service pipe comes in. Make sure nobody is using water, the dishwasher and washer are off, and the softener is not regenerating. Then look at the meter dial. Most meters have a small low-flow indicator, frequently a small triangle or star, which turns with even a trickle. If it moves, water is leaving somewhere.

The toilet test

Place a few drops of food colouring in each toilet tank. Do not flush for fifteen minutes. If colour shows in the pan, the flapper is leaking. A toilet that never stops running can pour away a startling amount of water every day without making much noise. A new flapper is cheap; our running toilet guide shows how to fit one.

Other common leaks

• Outdoor taps left dripping or a split hose bib inside the wall.
• Water softener stuck in regeneration, sending water to drain continuously.
• Humidifier on the furnace with a stuck-open solenoid.
• Irrigation system with a broken head or a leaking valve.
• Relief valve on the water heater dripping into a drain where nobody sees it.
• Hidden pipe leaks under the slab or in walls.

Isolating the leak

If the meter is moving and you have checked toilets, close the shut-off under each toilet and look at the meter again. Then try the valve to the softener, the humidifier and the outdoor taps. When the dial stops, you have found the branch. If it never stops, the leak may be under the slab or in the service pipe, and that needs leak detection.

Billing and estimates

Vaughan bills water based on meter readings. If a reading was estimated and then corrected, a bill can look high without any leak. Compare the readings on the bill with what your meter shows. If you have repaired a leak, the City may have a process for reviewing high bills; check current City of Vaughan policies.

See also: leak warning signs.