Considering all the operating cycles they go through, toilets generally are pretty reliable. Once in a while, though, water may continue running from your tank into the bowl after the tank seems to have refilled sufficiently. This may happen because the rubber tank ball above the discharge opening leading to the bowl is not seating properly. To check this out, just add a little food coloring to the tank when it’s filled; if the color seeps into the bowl, then you know that the ball is not seating tightly. It may have swelled or distorted with age and should be replaced.
First, shut off the water supply to the toilet with the shut-off valve that should be just under the tank. Unscrew the old ball from the rod to which it is attached and replace it with a new one. Be sure the rod is straight and moves up and down freely. Be sure, too, that the seat of the discharge opening is clean and smooth; scrape and sandpaper it if necessary to provide a smooth, uniform surface for the ball to seat on.
The trouble also may be with the float that operates the supply valve. It may be allowing water to rise too high in the tank and then into the overflow opening. So just bend the rod that the float is attached to downward, just enough for the supply valve to cut off incoming water below the overflow opening.
Note: If the water level continues to overflow, than you need to replace or repair the ballcock.
If you’d like some help with this or any other toilet problems as well as any other plumbing needs, call your local licensed plumbing contractor.
PAMCANI (The Plumbing & Mechanical Contractors Authority of Northern Illinois) is comprised of over 400 union contractors and sustaining members who provide and maintain plumbing, heating and cooling systems for institutional, commercial, business and residential applications. This non-profit trade organization invests over $3 million annually in the promotion, advancement, education and training of apprentices, journeymen and contractors, and actively works to raise awareness about water and energy conservation. Headquartered in Downers Grove, PAMCANI covers DuPage, DeKalb, Kane, Kendall, Lake and McHenry Counties.