We’ve all experienced it… your toilet flushes and refills just fine, but then it won’t stop running.  Or perhaps it stops running, only to start again in a few minutes, and it does so over and over.

The running sound gets annoying.  It wastes water.  Worst of all, it’s not good for the toilet.

But is the jiggle-the-handle trick the best way to stop it?

Anatomy of a Running Toilet

Toilets are simple, yet brilliantly functioning devices.  In order to understand why they run, let’s take a look at how they work.

When you press down on the handle to flush a toilet, the handle lifts up on a chain, which then lifts up on the flush valve, often called a “flapper” (in some toilets the flapper is a ball shape).  Water then drains out of the tank, down into the bowl, and it all flows out of the outlet.

When the water drains, the float ball drops, opening the inlet valve to let new water in (sometimes the float slides up and down the inlet tube).  As new water comes in, the flapper closes, and the tank refills.  Once it is full enough to lift the float ball, the valve closes and the toilet should stop running.

First things first

Before making any repairs to a toilet, shut off the water source on the supply line, and flush the toilet so that all of the water runs out of the tank.  You may have to observe normal flushing before shutting off the water source in order to diagnose the problem.

Shut your flapper

Issues with the flapper are the most common causes of running toilets.  Although they can often be temporarily solved by jiggling the handle, more permanent solutions are the best option.

Sometimes the flapper may catch on the chain.  A couple of possible solutions include replacing the chain with a sturdy piece of string—nylon or dental floss will work—or threading the chain through a drinking straw or other small, plastic tube.  Make sure the replacement is the same length as the chain to allow proper function.

The hinges of the flapper may warp or crack over time causing them to stick, holding the flapper open despite new water flowing in.  The flapper may also fall out of alignment with the outlet hole flowing to the bowl.  In either case, the tank won’t fill, and the flapper will need to be replaced.

The flapper may also need to be replaced if the rubber seal has deteriorated, allowing for a slow leak into the bowl which causes the toilet to run periodically after it has fully filled and stopped running.

Troubleshooting other problems

After hundreds, even thousands of flushes, sometimes the float needs to be adjusted downward to the proper fill line.  If the toilet is getting too full without the float and valve assembly stopping the flow, the increased pressure can cause leaks through the flapper.  Loosen the screws on the arm of a ball float, or pinch the metal clamp on a float that moves up and down the fill tube and adjust the float slightly downward so the valve will close at a lower water level.

It is also possible that the float and valve assembly or the flapper may accumulate mineral buildup causing improper mechanical functioning or an inadequate seal.  Check all parts for mineral deposits, and use an old toothbrush and lime cleaner to scrub off the minerals.

If you can’t stop your toilet from running with these simple repairs, it’s time to call in the professionals. Our expert plumbers can diagnose your toilet troubles and make repairs so that you can stop wasting water (and money!) on a toilet that just won’t quit. Schedule your plumbing service now.