Toilet Running Constantly — Flapper, Fill Valve, and Float Fixes

A constantly running toilet wastes up to 200 gallons of water per day. The cause is almost always a worn flapper, a misadjusted float, or a failing fill valve — all of which cost under $20 to fix and take less than 30 minutes.

1. 1

   Step 1: Identify whether water is going into the overflow tube

   Remove the tank lid and look at the overflow tube — the tall tube in the centre of the tank. If water is flowing into the top of this tube, the water level is set too high (adjust the float — see Step 3). If the water level is below the top of the overflow tube but you can hear water running, the flapper is not sealing (see Step 2).

2. 2

   Step 2: Replace the flapper

   The flapper is the rubber seal at the bottom of the tank that covers the flush valve opening. Turn off the water supply valve behind the toilet, flush to empty the tank, and remove the old flapper by unhooking its ears from the overflow tube pegs and disconnecting the chain from the flush handle arm. Snap the new flapper on, connect the chain (leave 1/2 inch of slack), turn the water back on, and test.

3. 3

   Step 3: Adjust or replace the fill valve and float

   If the water level is too high (water spilling into the overflow tube), adjust the float downward so the fill valve shuts off when the water level is 1 inch below the top of the overflow tube. On ball-float assemblies, bend the arm down or adjust the screw. On modern cup-float fill valves, pinch the adjustment clip and slide it down. If the fill valve does not shut off regardless of float position, replace the fill valve.