Basic toilet system repair is a matter of replacing small parts. Observe the mechanics of your toilet system to determine which replacement will be the fix. While some people pay a plumber to do this, it's possible to repair a toilet system yourself if you can determine what is causing the problem. Simple problems like toilets that won't stop running or ones that don't flush completely can be solved with household tools and a little bit of elbow grease.
Remove the tank lid. Put a towel in the tub or empty floor space and place the lid on top of it to prevent chipping.
Adjust the flush chain if the flapper valve, which is connected to the bottom of the chain, has a significant gap when it is in the "closed" position.
Press up and down on the flushing handle and observe the flapper valve to see if it fully closes. Replace the valve if it doesn't.
Check the flapper valve gasket for wear and tear. Replace as necessary.
Jiggle the flushing handle. Check for any unusual resistance, such as the handle moving tightly or loosely. If the resistance feels normal, the chain probably is intact.You may need your socket set or screwdriver to adjust, depending on which type of hardware is used on the part.
Open the lid and place it to the side on top of a towel.
Check the fill valve to see if it's damaged or doesn't open. If it's not opening, your tank most likely is empty or low on water.
Look at the ball cock valve and check the float ball, which is attached to it by an arm and rides the surface of the tank water. A damaged float ball will stay in a low position, which closes the fill valve and prevents flushing. Replace the float ball if it's damaged.
Examine the flush chain's length and adjust if it's too long to open the valve.