Field guide for Burlington owners
Fixing a Running Toilet
A toilet that hisses or refills on its own is quietly wasting water. Most fixes take a single part and a short afternoon.
- Steps you can safely take yourself
- What it looks like in Burlington houses
- When to put the wrench down and phone us
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The short answer
Three parts cause almost all running toilets: a flapper that no longer seals, a fill valve that does not shut off at the right level, or a chain that is too short or tangled. Test which one it is, replace that part, and the noise stops.
Key point
A toilet that hisses or refills on its own is quietly wasting water.
Step by step
- Lift the tank lid and watch through a flush cycle.
- Check the water level. Water trickling down the overflow tube means the fill valve sits too high or is wearing out. Lower the float, or replace the valve if adjusting does not help.
- Check the chain. Leave it a touch loose. Too tight and the flapper cannot close; too loose and it can catch underneath.
- Do the dye test. Add food colouring to the tank, wait twenty minutes without flushing, and look in the bowl. Colour means the flapper leaks.
- Replace the flapper. Shut off the supply at the wall valve, flush to empty, unhook the old flapper and fit one that matches your flush valve size, usually two or three inches.
- Replace the fill valve if needed. Turn off the supply, empty and sponge the tank, unscrew the coupling underneath, fit the new valve to the correct height, and reconnect.
- Refill and recheck. The water line should rest roughly 2.5 cm under the rim of the overflow tube.
Dual-flush and newer designs
Some modern toilets use a canister or tower-style flush valve instead of a flapper. The principle is the same: a seal at the bottom wears out. Replacement seals are model-specific, so note the brand and model, usually stamped inside the tank, before buying parts. A seasonal reminder for the rest of the house is in our spring plumbing checklist.
Have this ready when you call
- Which fixture, which floor
- Whether the main is closed
- Rough age of the house and heater
- Any past floods or drain work
The moment to phone us
- The shut-off valve under the tank leaks or will not close.
- The tank or bowl is cracked, or water seeps from the bolts between them.
- The toilet rocks or leaks at the floor, which suggests a failed seal or flange. See toilet repair.
- The toilet is old enough that a replacement would save water and effort. See toilet installation.
First move in a leak
Close the main shut-off, open a low tap to drain pressure, then call (365) 464-5184.
Burlington specifics
Mineral content in Burlington's lake water gradually stiffens rubber flappers and crusts fill valve seals, so replacing those parts every several years is normal. A running toilet can add noticeably to a Halton Region water and wastewater bill, since both are charged on metered use. If your bill jumps unexpectedly, a silent leak like this is the first thing to check; our guide on water bills and leaks explains how to read your meter for a leak test. Rural homes on wells, such as in Carlisle, hear the pump cycle more often when a toilet runs, which is another useful clue.
Bring the old part: take the old flapper or fill valve to the store. Matching size and style is easier side by side than from memory.
Questions we hear
My toilet refills briefly on its own now and then. Why?
That is called phantom flushing. Water leaks slowly past the flapper, and the fill valve tops the tank back up. A new flapper usually fixes it.
Are universal flappers reliable?
They fit many toilets, but some models, especially low-flow designs, need a specific flapper to flush correctly.
Should I use in-tank cleaning tablets?
Many manufacturers advise against them because the chemicals can degrade flappers and seals.