Toilet Fill Valves

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400A - Universal Fill Valve

Fluidmaster 400A Toilet Fill Valve
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To fix a noisy toilet, Fluidmaster® recommends using the 400A toilet fill valve in older, larger toilets, that date prior to 1994 with flush volumes between 3.5 and 7 gallons per flush. Fluidmaster®’s 400A Universal Toilet Fill Valve is the #1 best-selling fill valve in the world! A universal design, with an adjustable height from 9″ to 14″ to fit most toilets. The 400A offers quick refill rates and replaces ballcocks and other toilet fill valves. A trusted and proven toilet fill valve, the 400A is built to last from corrosion-resistant materials for a long lifespan. This code approved, anti-siphon design, won’t contaminate the fresh water supply. Some toilet models not supported: Glacier Bay® or Niagara® Flapperless Toilets, One Piece Toilets. Does not replace Side Entry Valves. Fluidmaster’s late Founder invented the fill valve technology in 1957.

  • The original 400A was first introduced in 1975
  • The #1 selling fill valve in the world
  • The #1 solution to fix noisy toilets
  • Easy to install, Universal fit
  • EZ-Twist height adjusts from 9″ to 14″ to fit most toilets
  • Trusted by toilet manufacturers and plumbers worldwide
  • 5 year warranty

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.

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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:

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


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
  • Also Replace toilet flapper replacement
  • Enhance Toilet Cleaner System

Frequently Asked Questions


Cancer and Reproductive Harm -


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