Fix a leak

Have you received an unusually high water bill? Or do you just want to be sure your home is as water efficient as possible? Use the following resources to detect and identify potential sources of water leakage in your home.

Step 1: Use your water meter to detect leaks

  • Locate your water meter – your home’s water meter is commonly located in your basement, where the City water pipes enter your home or building.
  • Locate the ‘low flow indicator’ on the face of your water meter – the low flow indicator is usually a small red or black triangle or dial on the face of the meter.
Water meters in Guelph
  • Ensure no water is being used in the home and check to see if the meter is registering a leak – make sure there is no water running in the house (i.e. turn off all faucets, water-using appliances, etc.), and then check to see if the indicator is turning, moving or shaking. If it is, this means that water is flowing through the meter and you have a leak.

Slow Leak Detection Test

You can also use your water meter to check for slow leaks overnight. Record your meter’s reading at night once you are done using water for the day, and then again in the morning before using any water. The numbers on your water meter are read like a car’s odometer. If the meter shows usage, you have a leak. If you have a water softener, we recommend conducting this test on a night when your water softener is not recharging.

If your meter indicates that you have a leak, use the following checklist to help identify the source of leakage in order to make necessary repairs.

Step 2: Locate the source of the leak


Toilets are by far the most common source of home water leakage.

  • First, remove the lid from the toilet tank. Look and listen for obvious leakage (e.g. water running into overflow, or out of the bottom of the tank). If noise is detected but no visible water moving, chances are that water is leaking through the flapper (located at the bottom of the tank, activated when flushing).
  • Use the “dye test” to check for flapper leakage.
    • Carefully remove the toilet tank cover.
    • Drop a leak detector tablet or a few drops of coloured food dye into the tank.
    • Wait a few minutes and then check the water in the toilet bowl.
    • If the coloured dye has seeped into the water in the bowl, without having flushed the toilet, there is a leak.

Leaky faucets or valves

  • Check all faucets and valves for leaks (inside and outside). Washers or cartridges may need replacing.
  • Check to make sure no faucets have been left running.

Water softener

  • Check for overflow
  • Check settings. How many times a week is the softener regenerating and how long does the process take?
  • Put the water softener on by-pass and see if your water meter stops running.

Additional sources

  • Hot water tank leaking
  • Furnace mounted humidifier valve leaking or malfunctioning
  • Water-primed floor drain leaking or malfunctioning
  • Washing machine or dishwasher running or malfunctioning
  • Sprinkler system leaking or left running
  • Outdoor hose bib leaking or left running

It is important to note that Water Services customers are required to pay for all water that passes through their meter, whether due to a leak or plumbing malfunction, or increased consumption.

It is the sole responsibility of the homeowner to undertake all necessary plumbing repairs and maintenance to stop water waste. The City is not responsible for internal plumbing leaks and is not privy to the source of leakage within the home. If you are unable to locate the source of leakage or perform necessary repairs, please contact a qualified plumbing professional.

For more information about a high water bill or reading your water meter, contact Guelph Water Services at 519-837-5627 or