If you hear the toilet running continuously, check the flapper chain length; it should have just enough slack to open fully without being so loose that it gets caught. Place the new gasket or washer onto the new valve's base, then insert it into the tank opening from below.
How to Reach the Valve Nut Under the Washer
Few household issues are as universally frustrating as a persistently running toilet or a weak flush, and the culprit is often a worn-out valve. Secure it by tightening the large retaining nut from above the tank.
The most common fill valve type is the ballcock or the more modern float cup design. Slowly turn the shut-off valve back on to let the tank refill.
How to Reach the Valve Nut Under the Washer
Adjusting the Water Level and Testing the Flush Once the hardware is secure, you must calibrate the new valve. If the tank is slow to refill, verify that the water supply line is fully open and that the valve’s internal screen is not clogged with debris.
More About How to change a toilet valve
Looking at How to change a toilet valve from another angle can help expand the discussion and give readers a second clear paragraph under the same section.
More perspective on How to change a toilet valve can make the topic easier to follow by connecting earlier points with a few simple takeaways.