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Fluidmaster Fix It Zone


Toilet Fill Valve Taking Too Long To Fill

Several things cause a slow-filling or non-filling valve:

  • After several years of use, the seal of the 400A fill valve can become swollen, causing a slower fill.
  • The inlet of the valve or the water supply line is plugged with debris.
  • For new installations, if using a straight pipe as a water supply line, it may be extended too far inside the bottom of the valve shank.
  • For new installations, the valve cone washer may have been used with the wrong supply line.

The solutions are:

  • Replace the swollen seal with the # 242 seal. They are available at your local hardware stores that carry Fluidmaster products.
  • The valve can be cleaned by using the house pressure to clear debris from the valve body. Turn the water off, flush the tank and remove the top cap. Hold a cup upside down over the fill valve and turn on the water to the toilet. You should get a forceful stream of water coming out of the fill valve. If no water or very little water flows up through the valve, you may have debris lodged deeper in the valve. Simply remove the water supply line under the tank and use a metal hanger that you can straighten. Start at the top of the valve and ream out the center of the valve until the debris drops out from the bottom of the valve. If this does not resolve your problem, you may want to repair your valve with a new # 242 seal.
  • Shut off water supply, unscrew the coupling nut and cut the supply line shorter. It should not extend more than ½” inside the fill valve shank.
  • If you used the cone washer that was supplied with the Fluidmaster Kit on a flexible supply line, you have plugged the shank. Simply remove the cone washer and use the supply line as is. If you threw away the cone washer from the supply line, you will need to replace the supply line.