Fluidmaster 400A vs Fluidmaster 400H: Which Is Better?

If you value a durable brass shank and consistently quiet operation, choose Product A; if you want separate bowl water level adjustment and a tool-free, widely reviewed installation, go with Product B.

The key differences: Material / Shank — Fluidmaster 400A: Brass shank with plastic body, Fluidmaster 400H: Plastic and rubber construction (Brass shank is more durable and corrosion-resistant than plastic.); Water Level Adjustment — Fluidmaster 400A: Tank water level only, Fluidmaster 400H: Tank and bowl water level adjustment dials (B allows separate bowl water level tuning for flush power.); Noise Level (customer-reported) — Fluidmaster 400A: Generally quiet (8 positive vs 2 negative mentions), Fluidmaster 400H: Mixed; some quiet, some loud (201 positive vs 134 negative mentions) (A users more consistently report quiet operation.); Installation Ease — Fluidmaster 400A: Easy install; pre-installed shank washer, Fluidmaster 400H: Easy install; step-by-step instructions, tool-free hand-tighten nuts (B has extensive installation instructions and no-tool design; A is also easy.).

Across the specs we compared, Fluidmaster 400A comes out ahead on 3 and Fluidmaster 400H on 3. The better value depends on which of those wins matter most for how you'll use it — check live pricing on Amazon and weigh it against the pros and cons above.

Reviewers most often highlight: "Works well; restores toilet function." The most common complaint: "Durability issues; some fail within a year." Weigh that against the Fluidmaster 400H using the full pros and cons above to decide.

Reviewers most often highlight: "Easy installation in under 10 minutes." The most common complaint: "Mixed noise level; some find it loud." Weigh that against the Fluidmaster 400A using the full pros and cons above to decide.

It's based on AI analysis of 17,553 Amazon customer reviews (320 for Fluidmaster 400A, 17,233 for Fluidmaster 400H) alongside the full specifications of both products.