If you have a slow-filling or constantly running toilet, the issue could be the toilet cup float valve. A float cup device is attached to an actuating rod that controls the water level in modern toilets.
Water levels that are too low can cause slow refills after flushing or clogs, and water levels that are too high may cause continuous running after flushing. You should be able to adjust and repair the float cup valve yourself. Here are tips to repair the float cup valve in your toilet.
Shut Off Water to the Toilet
The shut off valve to the toilet is commonly located behind the toilet on the left . Rotate the handle right to shut off. If you can't find the shut off valve to the toilet or it doesn't have one, shut off the main water supply to the house. Flush the toilet to empty the tank. Clear remaining water with a towel or sponge.
Adjust Water Levels
Remove the toilet tank lid and set it in a safe place. The float should be on the left side. If the cup has screws, take off the cap attached to the tube with a screwdriver. If the float cup has no screws, push down and turn it left to remove.
Look for the attached spring clip. Grab the spring and move the cup down to lower water level. Turn on the toilet water and flush the to check for overfilling. Give it about ten seconds to fill. If it fills, turn off the water and put the cap back on the cup.
To raise the water level, slide the float cup up the rod. Check the shaft for buildup that could cause slow refills and clean with a steel wool pad. Turn on the water and flush the toilet to test. The water level should fill to around one inch under the overflow tube.
Know When to Replace the Valve
There are three signs you should replace the valve: if the water doesn't stop running after adjustment, you can't find the right adjustment to keep the water from running, or you hear strange noises. Shut the water off , disconnect the water supply, and empty the tank. Unscrew the retaining nut under the tank with adjustable pliers to take off the old valve and reverse procedure to install a new valve.
Float cup valves are simple to adjust and replace. If adjusting the float cup valve or replacement doesn't solve the plumbing problem, you have an issue elsewhere that need to be checked by a plumber.