Consumer Tips

What Causes a Leaking Toilet and How to Repair it

A running toilet can be a minor annoyance that gets worse over time and can cost you money on your bills because of wasted water. Below are some common reasons that cause leaking toilets, but don't fret! You can diagnose and even repair some minor issues that cause your toilets to run.

The toilet flapper (aka valve seal) is one of the most common sources of a leaking toilet. This is the rubber stopper piece located at the bottom of the fill tank. Check to see if the flapper needs to be replaced by removing the ceramic cover on the fill tank and looking at the mechanisms inside as you complete a test flush. Is the flapper secure on all sides when fixed to the drain? If not, it may need replacing. Is any part of the flapper torn, punctured, or unhinged from other pieces? If so, it definitely needs replacing. Is it free from obstructions between it and securing to the drain? Sometimes the flapper chain can get stuck in the drain and needs adjusting.

The flapper is attached to the flush handle with a flapper chain. Make sure the chain is attached and not held on too loosely. The flapper chain can rust and break overtime, needing replacement.

The float is the balloon-shaped rubber device fastened to the fill valve with a handle (Note: in newer units, the float is part of the fill valve assembly). If the float level is too high, water will run into the overflow tube and the toilet will continue to run. To correct this, bend the handle of the float downward until water stops overflowing. To adjust a newer float assembly, turn the screw on top of the unit left to increase the tank fill level or right to decrease the fill level.

The overflow tube is the drainage tube that determines how much water goes into the toilet bowl by triggering the fill valve when to stop. The overflow tube needs to be sized to the correct height to ensure not too much or little water flows into the bowl each flush.

Check the fill valve (also called a flush valve) is working properly if all prior parts have been checked or replaced. The fill valve is the main unit in the fill tank responsible for adding new water to the tank each time the toilet flushes. If the valve is not shutting off after filling the tank, it needs to be replaced.

If all other parts inside the fill tank are working or have been replaced, the fill tank may not be fastened to the toilet bowl correctly. If water is leaking onto the outside of the toilet bowl or onto the floor, this could be the problem. In this case, the tank bolt may need to be tightened with a wrench or replaced or the spud washer (located at the base of the fill tank where the toilet bowl connects) may need to be replaced. These repairs are more complicated as they require proper tools and possibly an additional person to assist as the water source will need to be shutoff, the fill tank and bowl drained, and the fill tank and bowl to be separated to install new parts.

Call the Arizona Plumbing Council at 602-285-5563 to be referred to an expert, licensed Plumber who can help you with your plumbing needs.