← All repairs

Toilet · Repair Copilot

Toilet keeps running

A toilet that runs non-stop wastes gallons of water and that trickling sound never stops. The culprit is almost always inside the tank: a worn flapper, a chain that's too tight, or a fill valve set too high. Take the lid off, point your camera inside, and a 30-year plumber persona talks you through the fix — no wall-opening, no gas, just the parts you can reach.

🎙 Prefer hands-free? Talk it through live

Free · uses your phone camera · no app, no signup. SightLine will ask what it needs to see and guide you one step at a time.

Steps to fix toilet keeps running

  1. Take off the tank lid and set it somewhere safe, then watch one flush cycle.
  2. Check the flapper at the bottom — if it's warped or won't seal, water leaks into the bowl and the valve keeps refilling.
  3. Make sure the lift chain isn't too short or tangled, holding the flapper open a crack.
  4. Check the water level: it should sit about an inch below the top of the overflow tube — adjust the fill valve down if it's overflowing.
  5. If the flapper and level are good but it still runs, replace the fill valve (a cheap, tool-light swap with the water shut off).

Safety first: if a step calls for gas, a main water or sewer line, a service panel or main breaker, or a sealed refrigerant system, stop and call a licensed pro — Repair Copilot will tell you when you're there.