How to Stop a Running Toilet (Flapper Replacement)
Time required: 10-15 mins · Difficulty 1/5
Est. DIY Parts: $5 - $10 · Pro Service: $150 - $200 · Est. Savings: $140 - $195
* Estimates based on regional/national contractor rate benchmarks. Actual part prices vary by brand and retailer.
Parts & Tools You'll Need
- Universal 2 in. Toilet Flapper
- Complete Toilet Repair Kit (Fill Valve + Flapper)
- None required — fully hand-tool-free
Step-by-Step Manual
- Turn off the water supply Turn the shutoff valve behind the toilet clockwise until it stops, cutting off water to the tank.
- Drain the tank Flush the toilet and hold the handle down to let as much water as possible drain from the tank.
- Detach the old flapper Unclip the flapper's ears from the pegs on either side of the overflow tube, then disconnect the chain from the flush lever.
- Match and buy the right flapper Bring the old flapper with you (or match the brand/model) — flapper size and shape vary between toilet brands like Kohler, American Standard, and Toto.
- Install the new flapper Clip the new flapper onto the same pegs, then attach the chain to the flush lever with a little slack — about 1/2 inch when the flapper is closed.
- Turn the water back on and test Open the shutoff valve, let the tank refill, and flush a few times to confirm the toilet shuts off completely and doesn't keep hissing.