Toilet Keeps Running: Who Should You Call?
Urgency: SoonUpdated 2026-08-31
Short answer
A toilet that runs continuously almost always has a worn flapper or a misadjusted fill valve. Both are inexpensive parts and a straightforward DIY replacement. Call a plumber if the tank cracks, the water shut-off valve is seized, or the toilet rocks on the floor — that last one means the flange or wax ring has failed.
Who to call: A plumber or handyman — though most running toilets are a genuine DIY fix.
What to do right now
- 1Lift the tank lid and check whether the flapper is sealing on the flush valve seat.
- 2Confirm the water level sits about 2.5 cm below the top of the overflow tube.
- 3Add a few drops of food colouring to the tank — colour in the bowl within 15 minutes means the flapper leaks.
- 4Shut the supply valve behind the toilet if you need to stop the waste immediately.
Most likely causes
- Worn flapper
- Rubber hardens with age and chlorine and stops sealing. A $12 part.
- Fill valve set too high
- Water spills into the overflow tube and the valve never shuts off.
- Chain too short or too long
- Holds the flapper slightly open or tangles under it.
- Mineral build-up on the valve seat
- Hard water leaves scale the flapper cannot seal against.
What it typically costs in the GTA
$10–$30 in parts to do it yourself. $120–$250 for a plumber to replace the internals. $400–$800 to replace the toilet entirely, installed.
Ranges are typical market pricing for the Greater Toronto Area and vary with access, age of the home, and time of year. Always get the scope in writing before work starts.
What it's costing you
A steadily running toilet can waste several hundred litres a day. On a metered GTA water bill that is a noticeable monthly increase — usually far more than the part costs to replace.
When it isn't the flapper
Water on the floor, a toilet that rocks, or sewer smell means the wax ring or floor flange has failed. That is a plumber's job — the toilet has to come up and the flange may need repair.
Get the right pro on it
Describe the problem in your own words. We’ll work out which trade you need and connect you with suitable local pros. Free, no obligation.
Frequently asked questions
- Is a running toilet an emergency?
- No, but it wastes water continuously. Shut the supply valve behind the toilet until it is fixed.
- Why does my toilet run for a few seconds every so often?
- That is phantom flushing — a slow flapper leak lowering the tank level until the fill valve tops it up.
- Should I repair or replace an old toilet?
- If it is pre-1995 and using 13 litres per flush, replacing it with a modern low-flow model often pays for itself in water savings.