Easy solution to overflow problem

Do-it-yourself plumbing fix

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Q: I’d like to understand just how water comes into the toilet tank. I have two toilets that overflow, and I cannot figure out how to stop it. I’ve tried to lift the ball on one; the other is on a cylinder.

All the same, how does the water get into the tank? Getting it into the bowl is obvious.

A: For the modern toilet to work properly, two things have to happen: 1. Enough water must arrive in the toilet tank to effectively flush; and 2. The water in the tank must discharge into the bowl with enough force to create a siphon effect to discharge the waste from the bowl into the waste line.

The water in the tank can’t be too high or too low. Too much and water constantly runs through the overflow tube into the bowl. Too little and not enough pressure is created to effectively deliver the package to the city sewer system.

The simple answer to your question is that water enters the tank from a valve outside on the lower right side of the toilet tank, moves up a flexible pipe and into the fill valve inside the toilet. How water enters the tank is not the problem. The problem is that the water level in each tank needs adjusting.

You describe one old-style fill valve and one new-style cylindrical fill valve. Adjustment for both is an easy do-it-yourself fix, and best of all it’s free.

The old-style fill tube uses a plastic buoyant ball screwed on a threaded rod that lowers when the toilet is flushed, opening the valve to allow the tank to refill.

As water fills the tank, the ball rises with the water level and closes the fill valve, shutting the water off. There is a screw on top of the fill valve to adjust the movement of the valve. Turn the screw clockwise to reduce the water level in the tank.

There should be a line on the overflow tube marking the proper water level. Adjust the screw until the water hits the line. Do not bend the rod to try to fix the drip. In a short period of time, pressure from the water in the tank will move the ball in exactly the opposite direction you want.

Newer fill valves look like a plastic cylinder. The cylinder actually is a float and is adjustable up and down to control the water level.

There are at least a couple of designs for this type of fill valve. They differ in how to release the cylinder to adjust it up and down. We suggest you identify the maker of the valve you have and go to its website to get a quick tutorial on how to adjust that particular valve.

Here are URLs for a couple of videos showing two different valves being adjusted: and

This said, you should consider replacing the rod-and-ball-style fill valve with the cylindrical model. It has seen its best days, and replacement is as easy as shutting off the water to the tank, unscrewing the nut attaching the fill valve, removing the old valve and replacing it with the new one.

Cost for the part is about $10 to $20. The job will take about an hour, and the old toilet will provide many more years of worry-free service.









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