5 Common Toilet Issues and Their Causes

5 Common Toilet Issues and Their Causes

Does your toilet run constantly? Does  it flush slowly? Maybe it gets clogged on a regular basis. No matter what the issue, our plumbing experts know how frustrating toilet problems can be. Here are the most common issues and the reasons they may be happening:

Spontaneous Refills

If you hear the slow trickle of your toilet’s tank filling up out of nowhere, don’t worry – your toilet doesn’t have a mind of your own. Many people call this issue the “phantom flush” and it’s usually a very slow leak from the tank into the bowl. This issue is often caused by a bad flapper or a bad flapper seat. (The flapper is what seals the hole between the tank and bowl.)

A Weak Flush

If your toilet bowl empties slowly and has a “weak” flush, there’s a good possibility that the flush holes underneath the rim of the bowl are clogged. Try using a piece of wire to poke the holes and loosen any debris. If it’s still emptying slowly, use the same technique on the siphon jet at the bottom of the drain.

Less Water in the Bowl

Do you flush your toilet and bowl fills up normally, but after awhile, there seems to be less water in it? Two things could be causing this issue: Water could be slowly siphoning from the bowl by a partial clog up in the colon of the bowl or the bowl may actually have a crack in the interior colon or piping. (The latter is less common and requires installing a new bowl.)

Constant Running

If you hear water running constantly in your house, you may want to check your toilet. A constantly running toilet not only wastes water, but is usually caused by water continuously running out of the tank and into the bowl, which prevents your fill valve from shutting off. Check your flapper, your flush lever assembly, and the fill valve itself for signs of damage. Also check for any general debris that could be getting in the way of these things operating correctly.


Most toilets have five seals that are meant to prevent leaks: the largest seal is between the tank and the bowl and the smaller seals are around the mounting bolts and the base of your flapper. If your toilet is experiencing a leak and you’re not sure where it’s coming from, you’ll likely have to check all of the seals to find out which is faulty. You can also try tightening your bolts – sometimes this is enough to stop a leak.

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