Why Does Your Toilet Keep Running?
A running toilet is almost always caused by one of three things: a worn-out flapper (the rubber seal at the bottom of the tank), a faulty fill valve, or a float that's set too high. A running toilet can waste up to 200 gallons per day - that's $50-$100+ added to your monthly water bill. Here's how to diagnose and fix each cause.
1. Check the Flapper
The flapper is the rubber disc at the bottom of the tank that seals water in between flushes. Over time, it warps, cracks, or collects mineral buildup and stops sealing properly. Drop a few drops of food coloring in the tank - if color appears in the bowl within 15 minutes without flushing, the flapper is leaking. Replacement flappers cost $5-$10 and take 5 minutes to swap. This fixes about 60% of running toilets.
2. Check the Fill Valve
The fill valve controls water flowing into the tank after a flush. If it's worn out or stuck, it can run continuously. Listen: if the sound is a constant hiss, the fill valve is likely the problem. Replacement fill valves cost $10-$20 and most homeowners can swap them in 20 minutes with basic tools.
3. Adjust the Float
If the water level in the tank is too high, water continuously drains into the overflow tube. The float controls the water level - adjust it so the water stops about 1 inch below the top of the overflow tube. On a ball float, bend the arm down slightly. On a cup float, squeeze the clip and slide it down.
When Should You Call a Plumber for a Running Toilet?
If you've replaced the flapper and fill valve and the toilet still runs, there may be a crack in the overflow tube, a warped flush valve seat, or an issue with the toilet itself. Older toilets (pre-1994) use 3.5-7 gallons per flush vs. 1.6 for modern low-flow models. If your toilet needs major repair, upgrading to a new one often makes more sense. Trouble Free handles toilet repair and replacement across Peoria, Pekin, Morton, Washington, and surrounding areas. To keep your home trouble-free, call (309) 347-5309.