Running toilet in a Boca Raton home: how to diagnose it safely

Turn off water at the toilet shutoff valve if water reaches the floor. These checks use only the tank interior; do not remove the toilet or disconnect supply lines.

Five checks before calling a plumber

1. 1. Find the shutoff valve first

   Locate the oval-handled supply valve on the wall or floor behind the toilet and confirm it turns by hand. Turning it clockwise stops water to the tank. If water is overflowing onto the floor, close this valve before anything else. Do not force a seized or corroded valve; old valves can crack or start leaking at the stem, which is a reason to call a plumber.

2. 2. Listen and look at the water level

   Remove the tank lid carefully and set it on a towel; it is heavy and breaks easily. With the toilet idle, check whether water is spilling into the overflow tube. If the level sits above the marked water line or the top of the overflow tube, the fill valve is likely letting in too much water. If the level is normal but the tank keeps refilling every few minutes, water is probably leaking past the flapper into the bowl.

3. 3. Do a food coloring dye test

   Add a few drops of food coloring to the tank water, do not flush, and wait about 15 to 20 minutes. Color appearing in the bowl means water is seeping past the flapper or flush valve seal. Flush afterward to clear the dye. This silent leak can waste water without obvious noise, so the test is worth doing even on a quiet toilet.

4. 4. Check the flapper and chain

   Look at the rubber flapper at the bottom of the tank. A warped, stiff or mineral-coated flapper may not seal. The lift chain should have a little slack: too tight holds the flapper open, too long can get trapped under it. Adjusting chain length by one link is a reasonable homeowner step. If a replacement flapper is needed, match it to the flush valve size and toilet brand rather than using an assumed universal part.

5. 5. Observe the fill valve and float

   When the tank refills, the float should rise and shut the fill valve off at the correct level. Hissing that never stops, a float that sticks, or water continuing into the overflow suggests a worn or misadjusted fill valve. Many fill valves have an adjustment screw or clip described in the manufacturer instructions. If you are unsure of the model, close the shutoff valve and leave replacement to a plumber.

What to tell a licensed plumber

Share which toilet is affected, how often it refills, the dye test result, whether water is going into the overflow tube, the toilet brand if visible inside the tank, and any parts you have already replaced. Mention any water on the floor or a valve that will not close. Repair options depend on what the plumber finds; symptoms alone do not determine the fix.

For a Boca Raton condo or HOA community, confirm any access or building rules before scheduling, and provide your city, ZIP code and access arrangements when requesting service.

• Boca Raton plumbing service
• Fixture and toilet repairs
• Boca Raton hidden-leak checklist
• Palm Beach County covered-community guide

Florida Plumbing License #CFC1430609. Boca Raton is a service area, not a claim of a staffed local office.