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How to Fix a Fill Valve and Toilet Float

Originally posted on Men's Journal | By Max Winters | Last updated Nov 26, 2024 1:00 PM ET

A running toilet isn’t just a nuisance; it’s a major waste of water. That constant hissing noise you're hearing means that excess water is leaking from the toilet tank into the bowl, and your utility bill is taking a hit. The good news? You don’t need to be a pro to fix these plumbing issues. With a little know-how, you can troubleshoot and stop that constant flow it in no time.

Is my fill valve or float to blame for a running toilet?

The heart of your toilet’s functionality lies in the fill valve and the float. When either of these components isn’t doing its job, water may continuously flow. Here’s how to figure out which one is causing the problem:

Listen closely. If the toilet sounds like it’s refilling over and over, the fill valve may not be shutting off.
Peek under the tank lid. If the water level is above the correct level and spilling into the overflow tube, the float level might need adjusting.
Check for wear and tear. Look at the fill valve for any visible cracks or leaks. Without a proper seal, a fill valve can't regulate the water level and let's a slow leak though.

What if the flapper is the problem instead?

A worn or misaligned flapper can also cause a running toilet. To check, push down on the flapper while the toilet is running. If the flapper can't close, adjust the flapper chain length and check for mineral buildup. If those things look good and the water stops when the flapper does seal down, it’s time to replace the rubber seal. The flapper valve is inexpensive and can be swapped out in minutes.

How to Repair a Running Toilet

1. Adjust the Float

The float arm controls the water level in your tank. If it’s set too high, water will keep running into the overflow tube.

Locate the float: It might be a float ball on a rod or a cup sliding along the fill valve.
Test the water level: Flush the toilet and watch when the flow of water stops. The water should be about an inch below the overflow tube.
Make adjustments:

For ball floats, gently bend the rod downward to lower to adjust the float height to the proper water level.
For cup floats, find the adjustment screw and turn it counterclockwise to reduce the water level.

2. Replace the Fill Valve

If adjusting the float doesn’t do the trick, you may have a leaking fill valve might be beyond saving. Replacing it is straightforward but has a few basic steps.

Turn off the water supply: Use the shut-off valve near the base of the toilet.
Drain the tank: Flush the toilet to empty as much water as possible, then use a sponge or towel to soak up the remainder.
Remove the old fill valve: Unscrew the water supply line and loosen the lock nut holding the valve in place.
Install the new valve: Follow the instructions provided with your replacement fill valve, securing it snugly in place.
Reconnect and test: Reattach the water supply line, turn the water back on at the shutoff valve, and check for proper operation.

FAQ

Can I use universal replacement parts?

Generally, yes. Most universal flappers, fill valves, floats are designed to be compatible with standard toilets and come with assembly instructions. It's inexpensive and will quickly fix most running toilet issues. However, it’s a good idea to double-check the packaging just in case your model requires exact replacement parts.

Why is my toilet still running after all these repairs?

If none of these fixes work, you may be facing something more complex than a common plumbing issue. A cracked tank, a leaking toilet bowl, or a damaged overflow tube can cause damage over time so a professional plumber whoudl be consulted ASAP to save you time, effort, and hundreds of gallons of water.

This article first appeared on Men's Journal and was syndicated with permission.

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