How to diagnose and fix toilet problems including not flushing completely, filling slowly, and a stopped up toilet. Why low flow toilets can be a problem.

Fixing Common Toilet Problems

Toilet problems. Everybody has had them at one time or another. Whether it's a stopped up toilet, a constantly running toilet, a toilet that fills slowly, or a toilet that doesn't flush completely, troubleshooting and fixing common toilet problems is a homeowner's must-have skill, as are other plumbing fixes.

Different Toilet Valve Types

There are two different toilet valve types: ballcock fill valve types and float cup fill valve types. The ballcock fill valve is older and not encountered as often as the newer float cup fill valve type. The difference between the two is water supply hardware.

The ballcock uses a ball that floats on the water's surface. The float cup travels vertically on the fill tube. Here are a few types of common toilet problems and how to resolve them.

The Stopped Up Toilet

A stopped up toilet is the most common problem so it's a good place to start. To start with, looking in the bottom of the bowl reveals a round opening. Where this opening disappears from view it takes on an elliptical shape. Logically, that which disappears from sight might become lodged just a couple of inches beyond view.

The basic solution is to use a plunger. Seat the rubber end of it in the bottom of the bowl with the best seal possible. Plunge in and pull back out while retaining the seal. If water splashes out, too much force is being used. The water should soon go down of its own accord.

If the plunger doesn't clear the blockage, a toilet auger should be used. They may be rented.

The Constantly Running Toilet

When the toilet runs constantly, chances are that water is running into the overflow tube because the ballcock or the float cup needs adjustment. The ballcock link has an adjustment clip that can be pressed and lowered. With a float cup type, find the adjustment clip on the side of the float cup.

If this still does not make the toilet stop running, be sure that the refill tube that goes from the fill tube to the overflow tube is just above the overflow tube, not going into it.

The final thing that will make the toilet run constantly is a defective fill valve seal. This will need replacement.

The Slowly Filling Toilet

The most likely culprit when the toilet takes too long to fill is a clogged fill valve tube. Shut off the water supply valve at the wall. Remove the hardware on the top of the tube to gain access to the toilet fill valve tube. Now use a bottle brush or length of stiff wire to clear anything in the tube. Hold a glass over the fill tube and open and close the valve several times to flush out the tube. Reinstall the hardware.

The Toilet that doesn't Flush Completely

This can be a problem with the newer “low flow toilets”. Unfortunately, the effort to save water has backfired when multiple flushes are required. Another problem can be clogged entry into the bowl.

Under the rim of the toilet bowl are a series of entry holes. Clean each one, ensuring that water flows freely. Finally, examine the flapper in the bottom of the toilet. Is it old and rotted? Is it seating properly, Is the chain too long, causing it to hang up? Just replace the flapper and adjust the chain to 1/2” slack.

These toilet troubleshooting and repair tips should solve most toilet malfunctions. Use them and save on service calls from the plumber.