Your water bill jumps and nothing about your household changed. No new people, no filled pool, no extra laundry. So where is the water going? Almost always, the answer is a leak you cannot see or hear.
A hidden leak can waste thousands of litres a month and quietly wreck your home while it does. Here is how to track it down, starting with the most common culprits in Durham Region homes.
First, confirm it is a leak
Before you hunt, prove there is one. It takes ten minutes.
- Turn off every tap and water-using appliance in the house.
- Find your water meter and note the reading (or watch the leak-indicator dial if it has one).
- Wait 30 to 60 minutes without using any water.
- Check the meter again. If it moved, water is escaping somewhere. You have a leak.
The usual suspects, in order
1. A running toilet (the #1 hidden water waster)
This is the most common cause of a mystery bill by a wide margin. A toilet that runs or refills on its own can waste hundreds of litres a day, silently. Drop a few drops of food colouring in the tank, wait 15 minutes without flushing, and check the bowl. If colour shows up in the bowl, the flapper is leaking. We cover the full fix in why your toilet keeps running.
2. Dripping faucets and showerheads
A single drip seems harmless, but a steady drip adds up to litres a day per fixture. Check every faucet, inside and out. Worn washers and cartridges are cheap to replace and add up fast on the bill.
3. A leaking water heater
Check around the base of your tank for puddles or rust. A leaking tank wastes water and signals the unit is failing. If you spot water pooling, read the warning signs before it goes completely.
4. An underground or supply-line leak
If the meter test shows a leak but every fixture is dry, the leak may be in a supply line, under a slab, or underground between the meter and the house. These are invisible from inside and need proper leak detection. Signs include a warm or damp spot on a floor, a patch of unusually green lawn, or the sound of running water with everything off.
5. Outdoor faucets and irrigation
In summer, a cracked hose bib or a leaking irrigation line can run for weeks unnoticed. Check outdoor spigots and any sprinkler system for pooling or soft ground.
When to call a plumber
If the meter test confirms a leak but you cannot find it at a fixture, stop guessing. A hidden supply-line or slab leak needs equipment to locate without tearing up your whole home. We find the exact source, show you, and quote the repair flat before any work.
The longer a hidden leak runs, the more it costs you twice: on the bill and in water damage. Catching it early is always cheaper.
Call us at (647) 560-2817 or request a free estimate. We serve Ajax, Whitby, Oshawa, Pickering, and all of Durham Region, with 24/7 emergency service if a leak is actively flooding.
Frequently Asked Questions
How do I know if I have a hidden water leak?
Turn off all water in the house, note your meter reading, wait 30 to 60 minutes without using any water, then check the meter again. If it moved, you have a leak somewhere. From there, check toilets and faucets first, since they are the most common culprits.
Can a running toilet really raise my water bill that much?
Yes, dramatically. A toilet that runs or leaks past the flapper can waste hundreds of litres a day without any obvious sound. It is the single most common cause of a mystery water bill. A food-colouring test in the tank tells you in 15 minutes.
What are the signs of an underground water leak?
A leak between the meter and the house often shows up as a damp or warm spot on the floor, an unusually green or soggy patch of lawn, low water pressure, or the sound of running water when everything is off. These need professional leak detection to pinpoint.
Should I be worried about a small leak?
Yes. A small leak wastes water every hour it runs and can cause slow, hidden damage to floors, walls, and framing. It also only gets worse. Finding and fixing it early is far cheaper than the water bill plus repairs down the road.