Fix a Running Toilet
A constantly running toilet usually means the flapper inside the tank isn't sealing — wasting up to 200 gallons a day. A $5 flapper or fill-valve fix solves 90% of cases.
Tools
- ✓
- ✓for draining the tank
- ✓in case of drips
Materials
- +Match the size: 2" is standard on older toilets, 3" is common on most toilets made since ~2005 (especially 1.6 and 1.28 gpf high-efficiency models). Korky and Fluidmaster universal kits cover most.
- +If the flapper fix doesn't hold
Steps
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1
Diagnose which part is bad
Take the tank lid off and watch a flush cycle. If water trickles down the center overflow tube — the fill valve is set too high or stuck open. If you hear hissing and the flapper isn't sealing — it's the flapper.
Tip: Beginner trick: drop 5 drops of food coloring in the tank, wait 15 min without flushing. If color appears in the bowl, the flapper is leaking. -
2
Shut off the water and drain the tank
Close the supply valve, then flush once to drain. Sponge out the last inch of water at the bottom.
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3
Remove the old flapper
Unhook the small chain from the flush handle arm, then slip the flapper ears off the overflow tube pegs. Note the size — 2" is standard, 3" is common on newer high-efficiency toilets.
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4
Install the new flapper
Slide the new flapper onto the pegs, reconnect the chain. Leave just a tiny bit of slack — too tight and the flapper won't close, too loose and the flush is weak.
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5
Turn the water back on and test
Open the valve slowly. Once the tank fills, flush a few times and watch the flapper seat itself. Adjust chain length if needed.
Tip: If it still runs after 10 minutes, the fill valve likely needs replacement — same toolset, ~30 more minutes.