Is Your Toilet Running or Leaking? Here's What to Do
A running toilet can waste up to 200 gallons of water per day — silently driving up your water bill. A leaking toilet base can damage your floor and subfloor over time. The good news: most toilet problems come down to a handful of inexpensive parts that any homeowner can replace in under an hour.
Diagnosing the Problem
Before grabbing tools, identify what's wrong:
- Toilet runs constantly — Flapper or fill valve issue
- Toilet runs intermittently (phantom flush) — Worn flapper letting water seep into the bowl
- Water on the floor around the base — Wax ring seal failure or loose tank bolts
- Weak or incomplete flush — Flapper closes too quickly or low water level
- Tank takes too long to refill — Fill valve needs adjustment or replacement
Fix 1: Replace the Flapper
The flapper is the most common cause of a running toilet. It's a rubber seal at the bottom of the tank that controls water flow into the bowl.
- Turn off the water supply valve behind the toilet
- Flush to empty the tank
- Unhook the old flapper from the overflow tube ears and disconnect the chain from the flush handle
- Snap the new flapper into place and reconnect the chain (leave about ½ inch of slack)
- Turn the water back on and test
Cost: $5–15 | Time: 10–15 minutes
Fix 2: Replace the Fill Valve
If the toilet hisses or the water level is too high or low, the fill valve may need replacing.
- Turn off the water supply and flush the tank
- Disconnect the water supply line from the bottom of the tank
- Unscrew the locknut under the tank and remove the old fill valve
- Install the new fill valve, adjust the height per instructions, and reconnect the supply line
- Turn on water and adjust the float to set the correct water level (about 1 inch below the overflow tube)
Cost: $10–25 | Time: 20–30 minutes
Fix 3: Replace the Wax Ring
If water pools around the base of the toilet, the wax ring seal between the toilet and the floor flange has failed.
- Turn off water, flush, and disconnect the supply line
- Remove the tank lid and bail out remaining water with a sponge
- Unscrew the closet bolts at the base and carefully lift the toilet straight up
- Scrape off the old wax ring from both the toilet horn and the floor flange
- Press a new wax ring onto the toilet horn (wax side down) and lower the toilet straight onto the bolts
- Press down firmly, replace nuts, reconnect supply line, and test
Cost: $10–20 | Time: 45–60 minutes
Fix 4: Adjust the Flush Handle & Chain
If the toilet won't flush or the handle feels loose, the chain or handle may need a simple adjustment.
- Check that the chain has about ½ inch of slack — too much slack and the flapper won't lift fully; too little and it won't seal
- If the handle is loose, tighten the mounting nut inside the tank (note: it's reverse-threaded — turn clockwise to loosen)
Shop Toilet Repair Parts at ProFix
Find flappers, fill valves, wax rings, complete repair kits, and more in our Toilet Repair collection. We carry parts compatible with all major toilet brands including Kohler, American Standard, and TOTO.