Toilet Fill Valves

Products > Toilet Fill Valves

400A - Universal Fill Valve

Fluidmaster 400A Toilet Fill Valve
Click & drag to spin image (Shift + drag if zoomed in). Click to zoom in. Click thumbnail to reset.

Click & drag to spin image (Shift + drag if zoomed in). Click to zoom in. Click thumbnail to reset.

The 400A toilet fill valve was introduced in 1975 and is the #1 selling fill valve in the world. It fixes noisy toilets and slow filling toilets.

Best for toilets manufactured prior to 1994 that have 3.5 – 7 gallons per flush.

  • The #1 solution to fix noisy and slow filling toilets
  • Easy to install, Universal fit
  • EZ-Twist height adjusts from 9″ to 14″ to fit most toilets
  • Corrosion-resistant material
  • 5 year warranty

Some toilet models not supported: Glacier Bay® or Niagara® Flapperless Toilets, One Piece Toilets. Does not replace Side Entry Valves.

To download our free guide to fix common toilet problems please click here: Fluidmaster Toilet Repair Guide

For best performance of your toilet, consider replacing the flapper along with the fill valve. Fluidmaster recommends the  400CR Repair Kit that has both the 400A fill valve as well as the 2 inch 501 flapper.

Watch this video on how to install the Fluidmaster 400A Fill Valve:

If your fill valve runs continuously or you hear a constant hissing sound, you may have debris trapped in the valve. This video will show you how to properly remove debris from the 400A fill valve:

If removing the debris from the 400A fill valve did not solve your problem, then the next step would be to remove and replace the cap assembly of the 400A fill valve. This video will show you how to remove & replace the cap assembly:

If you are wondering what is the difference between the 400A and the 400AH PerforMAX® fill valve, we have just the right video for you:

To check your toilet’s flush volume, please click here.

400A - Universal Fill Valve

Download Installation Instructions

Fluidmaster Recommends

  • Upgrade Toilet Repair Kit
  • Also Replace 2" Universal Flapper
  • Enhance Toilet Cleaner System

Frequently Asked Questions


Cancer and Reproductive Harm -


The 400A - Universal Fill Valve is available online, from our following retail partners.