A weakly flushing toilet can be an embarrassing problem, especially if you forget to double flush after use. Fortunately, it's a problem that can usually be repaired.
Symptoms of a Weak Flush
Weak flushes often first become noticeable when a single push of the handle doesn't get the job done. You may need to flush twice, or even three times, to get rid of solids or excessive paper in the bowl. In some cases, the flush may be so week that even several flushes will be unable to clear the bowl.
In some cases, you may also notice that the bowl doesn't seem to fill completely after a flush, or the water level may drop between flushes so that there is an insufficient amount available for a strong flush. Low flow and water-saving toilets, particularly older models, can be prone to this problem, but standard toilets aren't immune. Inversely, sometimes there will be a higher water level in the bowl and not enough in the tank.
The flapper is the most likely culprit when it comes to a weak toilet flush. Flappers that close too quickly won't allow enough water to flow through the bowl to complete a strong flush. Cracked and damaged flappers, as well as those that aren't aligned properly, may leak water into the bowl. When this happens the tank level will be too low to provide a powerful enough flush to get the job done.
Hard water is another common cause, especially if the water level in the bowl is low. The hard water deposits clog up the water holes in the rim of the bowl so that water can't easily flow through from the tank when the toilet is flushed.
The final likely cause is a clog somewhere down the waste pipe. You may notice higher water levels in the bowl when this is the case.
Weak Flush Solutions
Solutions begin with checking the flapper assembly. If it is cracked or damaged, then a replacement will solve your problem. Otherwise, verify that it is properly aligned and adjust it and the fill tube as necessary so proper functioning.
For hard water problems, full cleaning of the bowl with a limescale remover should clear out the holes under the rim and solve the issue. If they are badly clogged, though, toilet replacement may be needed. A clogged toilet waste pipe will require a good plunging and possibly a drain cleaning.
Contact a plumber in your area for more help with toilet problems.