Fluidmaster 400A Toilet Tank Repair Fill Valve – 2 Pack | Universal Fit & 9–14 in Adjustable

Overview

Meet the Fluidmaster 400A Toilet Tank Repair Fill Valve, offered as a convenient 2-pack. Marketed as the world’s #1 best-selling fill valve, this kit blends a universal design with reliable performance. Its anti-siphon design helps protect your fresh water supply, and the valve is built to tolerate daily bathroom use with corrosion-resistant materials. While it supports many standard toilets, some models—such as Glacier Bay, Niagara Flapperless, One Piece Toilets, and Side Entry Valves—aren’t compatible. This kit focuses on straightforward repairs and upgrades that many households find practical for renewal or maintenance in busy kitchens and baths.

Adjustability and compatibility

One of the standout features is the EZ twist height adjustment, letting the valve fit tanks from 9 to 14 inches tall. That flexibility means you can tailor the setup to a wide range of toilet models without sourcing separate parts. The 400A is designed as a complete replacement kit, so you’ll have the essential components needed for most standard installations in a single purchase.

• EASY INSTALLATION: Quick and simple setup suitable for typical home repairs.
• ADJUSTABLE HEIGHT: 9 to 14 inches to accommodate many tank sizes.
• COMPLETE REPLACEMENT KIT: Includes all required parts for a full valve assembly.
• DURABLE MATERIALS: High-quality plastic resists daily wear and corrosion.
• UNIVERSAL FIT: Works with most toilets and single-port systems, meeting IAPMO specifications.

Real-world use and benefits

In real-life bathroom scenarios, a well-matched fill valve can support steady refills after flushing and reduce symptoms of running water. The 400A’s design aligns with everyday needs—homeowners trying to fix a slow or noisy refill, or someone upgrading an aging valve for better reliability. It’s a practical upgrade choice for DIY projects that aim to restore normal toilet function while keeping parts accessible and straightforward to replace.

Important notes

If your toilet model isn’t listed as compatible, or if you’re unsure about the tank height, you may want to verify compatibility before purchasing. Also remember that the kit does not replace Side Entry Valves. This Fluidmaster product carries a legacy of innovation dating back to its founder’s early fill valve work from 1958, emphasizing dependable design and ongoing innovation.

What you get and why it matters

This 2-pack provides two complete fill valve assemblies, which can simplify replacement in multiple toilets or keep a spare valve on hand for future maintenance. The included hardware and seals are designed for a smooth, tool-light installation, helping you complete the job with minimal disruption to daily routines.