Diagnose why your toilet will not stop running and decide if you need a plumber.
Updated April 2026
The flapper is the rubber seal at the bottom of the tank. Over time it deteriorates, warps, or gets mineral buildup, and water slowly leaks into the bowl.
Test: Put food coloring in the tank. Wait 15 minutes. Colored water in the bowl = leaking flapper.
DIY fix: $5-$10 part, 5 minutes, no tools. Pro range: $30-$80 installed.
The fill valve controls water flow that refills the tank after flushing. When it fails, the toilet runs constantly or cycles on and off.
DIY fix: $10-$20 universal valve, 15 minutes. Pro range: $60-$150 installed.
If the water level is above the overflow tube, water continuously drains into it.
Fix: Free. Adjust the float until water is 1 inch below the overflow tube top.
Call if: the toilet runs after replacing the flapper and fill valve, water on the floor around the base (wax ring, $50-$150), the toilet wobbles (flange, $150-$350), or cracks in the porcelain.
| Service | Installed cost |
|---|---|
| Flapper replacement | $30 – $80 |
| Fill valve replacement | $60 – $150 |
| General toilet repair | $100 – $300 |
| Wax ring replacement | $50 – $150 |
| Toilet flange repair | $150 – $350 |
| Toilet replacement (new unit + install) | $200 – $600 |
Based on national trade data and contractor experience. Updated April 2026. All ranges are for planning purposes only — not a quote or guarantee. Actual costs vary by region, scope, access, materials, and contractor.