Toilet Tank Running

Your toilet tank flushes fine, but doesn’t seem to know when to quit.  Either it runs continuously or it shut off, then starts running again.  A toilet tank that won’t stop running is not only noisy and annoying, it wastes a lot of water.  Fortunately, running toilet tanks are relatively easy to diagnose and repair.

First, take the lid off of the tank and see what kind of mechanism you have in your toilet tank.  Mechanisms may look different, but they all work on the same principles.  There is a flapper valve at the bottom of the tank that is attached by a chain to the flush lever.

Check the flapper valve first to see if it is working properly.  The pull chain or other debris may have gotten under the flapper valve which will cause the toilet to run constantly.  The flapper valve may have come loose and no longer seals properly.  If so, install a new flapper valve from any home improvement store.

If the flapper valve looks OK, check the float valve.  This may be a floating ball attached by a metal rod to the water inlet valve or a cylinderical float that fits around the inlet valve itself.  In either case, flush the toilet and watch the float as the tank fills.  When the float nears the top of the tank, the valve should close and the water should shut off.  If not, see if you can adjust the float valve to make the water shut off a little sooner.  If that doesn’t work, your float is probably leaking and you will need to install a new float and valve assembly.