American Standard Parts Guide: Where to Buy OEM Parts

American Standard has manufactured toilets in North America for more than 140 years. The brand currently holds the largest installed base of residential toilets in the U.S. market, which means parts demand for its most popular lines -- the Champion 4, Cadet 3, Cadet Pro, Edgemere, Vormax, and H2Option -- is consistently high. Unlike some imported brands, American Standard operates a dedicated parts infrastructure with searchable online catalogs, authorized dealer networks, and most parts stocked at major hardware retailers.

This guide identifies the correct part numbers for the most common American Standard models, explains which components require OEM sourcing and which accept reliable aftermarket alternatives, and maps the best purchasing channels for each part category. If you are deciding between models, see our best flushing toilets guide for full performance comparisons. For brand-specific model coverage, the American Standard brand guide covers the full lineup.

How Do I Find My American Standard Toilet Model Number?

American Standard uses a consistent model number format across its toilet lines. The tank model number is the most important number for internal parts (fill valves, flush valves, flappers, trip levers, tank-to-bowl gaskets), while the bowl model number is needed for wax ring sizing and seat compatibility. For most repair purposes, the tank number is what you need.

If the original sticker is missing or illegible, American Standard's customer service line (1-800-442-1902) can identify a model from a verbal description of physical characteristics and the tank dimensions. Photographs of the tank interior also help distinguish between flush systems, as described below.

What Flush Systems Do American Standard Toilets Use and Why Does It Matter for Parts?

Each flush system is described below with its defining characteristics, primary OEM part numbers, and aftermarket compatibility notes.

Champion 4 Flush System

The Champion 4 uses a proprietary 4-inch flush valve tower -- one of the largest in the residential toilet market -- combined with a wide 2.125-inch fully glazed trapway. American Standard's published MaP test score for the Champion 4 is 1,000 grams, the maximum achievable rating under the MaP flush testing protocol, and the toilet carries EPA WaterSense certification at 1.28 GPF on current production runs (earlier Champion 4 models flushed at 1.6 GPF).

The 4-inch flush valve tower is not interchangeable with any standard universal flush valve. The OEM flush valve assembly for the Champion 4 is part number 738310-0070A. The complete flush valve rebuild kit, which includes the tower seal, flapper disk, and trip arm connection, is sold as the Champion Flush Valve Repair Kit (part 738310-0070A complete or the subset 47808-0070A for the tower flapper disk only). These parts are stocked at Home Depot, Lowes, and Amazon from American Standard directly. Fluidmaster makes the Fluidmaster 555C and PerforMAX 555CX as aftermarket-compatible replacement flush valve assemblies confirmed to fit the Champion 4 -- both are widely available and owner-reviewed as reliable replacements.

The fill valve on the Champion 4 tank is an American Standard branded unit, but the mounting thread and float geometry are compatible with the Fluidmaster 400A and Fluidmaster 400AH (high-performance) aftermarket fill valves. The Fluidmaster 400A is the most universally recommended fill valve for American Standard Champion 4 owners based on aggregated owner reviews at Home Depot and Amazon. American Standard's OEM fill valve replacement for Champion 4 tanks is part 7301111-0070A.

Cadet 3 Flush System

The Cadet 3 uses a 3-inch flush valve with a tower-style flapper seat rather than a conventional hinged flapper. The Cadet 3 trapway is 2.125 inches fully glazed, and the toilet carries EPA WaterSense certification at 1.28 GPF on current models. MaP scores for the Cadet 3 range from 800 to 1,000 grams depending on specific configuration, with one-piece elongated variants typically scoring higher. The Cadet 3 series is one of the most-reviewed toilet lines in North America, and parts questions from owners are well-documented in retailer Q-and-A sections.

The Cadet 3 flush valve flapper tower uses a 3-inch seat. The OEM replacement flapper is American Standard part 7301111-0070A (shared with some fill valve kits -- verify the part matches your purchase). The Fluidmaster 502P21 and Korky 528MP are confirmed aftermarket replacements for the Cadet 3 flapper seat, with the Korky 528MP being the most frequently cited as a direct fit by Cadet 3 owners in plumbing forums and retailer reviews. The Cadet 3 fill valve is compatible with the Fluidmaster 400A, which is the standard aftermarket recommendation.

Cadet Pro Flush System

The Cadet Pro uses a 3-inch flush valve similar in diameter to the Cadet 3 but with a slightly different tower geometry. American Standard sells the Cadet Pro flush valve repair kit under part number 3174.105-0070A. The Fluidmaster 555C is documented as compatible with the Cadet Pro flush valve seat by multiple owner reviews. The fill valve accepts the Fluidmaster 400A as a standard aftermarket substitute.

VorMax Flush System

The Vormax and Vormax Plus models introduced in 2015 and 2019 respectively use American Standard's VorMax siphonic flush technology, which directs flushing water through a single hole at the top of the bowl rather than a traditional rim-jet or siphon jet arrangement. This design results in a high-velocity swirling action that American Standard's published testing credits with superior bowl cleaning and waste removal. The Vormax carries a MaP score of 1,000 grams.

The VorMax flush valve is proprietary to the VorMax platform and is not interchangeable with Champion 4 or Cadet 3 parts. The OEM flush valve for the Vormax is part 3316.105-0070A. The fill valve replacement for Vormax tanks is the American Standard part 7301111-0070A or the Fluidmaster 400A as an aftermarket substitute. As of June 2026, no third-party manufacturer has released a confirmed-compatible aftermarket VorMax flush valve; OEM sourcing from americanstandard-us.com or Ferguson is the correct path for flush valve replacement on Vormax models.

H2Option Dual-Flush System

The H2Option is American Standard's dual-flush two-piece toilet, offering a 1.0 GPF option for liquid waste and a 1.6 GPF option for solid waste. It carries EPA WaterSense certification. The H2Option uses a dual-flush tower with a push-button mechanism at the top of the tank rather than a side-mounted trip lever. The OEM dual-flush cartridge assembly is part 7301190-0070A. Because of the push-button tower design, there are no standard trip-lever-based aftermarket flush valves compatible with the H2Option -- OEM is required for the tower cartridge. The fill valve accepts the Fluidmaster 400A.

Which American Standard Parts Have Reliable Aftermarket Alternatives?

Where Can You Buy American Standard OEM Parts?

americanstandard-us.com/parts

The American Standard parts portal is the most authoritative source for OEM components. The site allows lookup by toilet model number, part category, and part number. It ships directly to consumers and shows real-time inventory. For parts that are in production, the American Standard store is the most reliable source because it guarantees genuine OEM components without risk of counterfeits or mislabeled aftermarket items. Shipping typically takes three to seven business days to most U.S. locations.

Ferguson Plumbing Supply

Ferguson is the largest plumbing wholesale distributor in North America and an authorized American Standard dealer. Ferguson locations stock a broader range of American Standard parts than most hardware retailers, including less common components such as tank lids in specific colors, elongated seat hinges for discontinued finishes, and the full range of VorMax and H2Option flush valve assemblies. Ferguson sells to both trade customers and the general public at most locations. The Ferguson website (ferguson.com) allows part lookup by American Standard model number and shows local branch availability.

Home Depot and Lowes

Both Home Depot and Lowes stock the most frequently replaced American Standard parts for Champion 4 and Cadet 3 models in their plumbing aisles. In-stock items typically include the Fluidmaster 400A (compatible fill valve), the Fluidmaster 555C (compatible Champion 4 flush valve), the Korky 528MP (compatible Cadet 3 flapper), tank-to-bowl bolts and gaskets, and toilet seats in elongated and round profiles. Less common parts -- VorMax flush valves, H2Option cartridges, trip levers in non-standard finishes -- are generally special-order or online-only at these retailers. Home Depot and Lowes both offer same-day in-store pickup for online orders when local inventory is available.

Amazon

Amazon lists the majority of American Standard's parts catalog through a combination of American Standard's own seller account and authorized distributor accounts. For common parts such as fill valves, flush valve towers, flapper disks, and trip levers, Amazon offers competitive pricing and Prime shipping that delivers within one to two days for most U.S. addresses. When ordering from Amazon, verifying that the seller is "American Standard" or a recognized authorized distributor such as Plumbing Supply Group or Repair Parts Plus reduces the risk of receiving mislabeled aftermarket components packaged to resemble OEM parts. The part number, not the listing title, is the definitive way to confirm you are ordering the correct component.

Local Plumbing Supply Houses

Independently owned plumbing supply houses in most U.S. markets carry American Standard accounts and can order any part in the current catalog, often with next-day availability for common items. These suppliers also maintain relationships with American Standard's regional representatives, which can be valuable for sourcing parts for discontinued models that are no longer listed on the consumer website. For Vormax, H2Option, and older Edgemere or Studio models, a local plumbing supply house is often faster than waiting for online shipping.

What Are the Key Part Numbers for American Standard Edgemere, Boulevard, and Studio Models?

Edgemere (Model 270AB001)

The Edgemere is one of American Standard's most popular right-height elongated two-piece models. Its tank uses a 3-inch flush valve with a tower-style seat compatible with the Korky 528MP flapper. The fill valve accepts the Fluidmaster 400A. The tank-to-bowl gasket is the standard American Standard 7301083-0070A. The Edgemere toilet seat bolt spacing is standard elongated, accepting most third-party seats including the American Standard 5321.010 slow-close seat and the Bemis 1500EC series. The Edgemere carries EPA WaterSense certification at 1.28 GPF and has a MaP score of 800 grams on standard configurations.

Boulevard Skirted (Model 3318.128)

The Boulevard's skirted trapway presents a particular challenge for wax ring installation because the skirt extends closer to the floor than a standard two-piece toilet. American Standard sells a Boulevard-specific wax ring kit (part 7381101-0070A) that accounts for the reduced clearance. The flush valve tower on the Boulevard is OEM-only as noted above. The fill valve accepts the Fluidmaster 400A. Tank lids for the Boulevard are porcelain and matched to the toilet color; purchasing a replacement lid requires specifying the finish (white is 0070A suffix, linen is 0200A suffix).

Studio Series

The Studio S toilet series uses tank internals closely matched to the Cadet 3, which means the Fluidmaster 400A fill valve and Korky 528MP tower flapper are generally compatible. The Studio S carries the same 1.28 GPF WaterSense certification as the Cadet 3 and Edgemere. The Studio's concealed tank design on some configurations limits access to the fill valve mounting point; American Standard's installation instructions for the Studio S recommend the specific OEM fill valve for that model (part 7301111-0070A) because the shaft length is calibrated for the tank depth.

Are American Standard Toilet Seats Proprietary or Universal?

American Standard's current seat lineup includes the American Standard 5321.010 Slow Close Round Front Seat, the 5325.010 Slow Close Elongated, and the 5325.019 EverClean Surface slow-close seat with antimicrobial glaze. The EverClean seats carry a 10-year warranty against toilet seat staining. For homeowners replacing seats on Champion 4, Cadet 3, Cadet Pro, or Edgemere models, any quality elongated seat from Bemis, Mayfair, or similar seat-only manufacturers will fit the standard bowl profile without modification.

For Champion 4 owners looking for a soft-close upgrade, see our guide to the best toilet seats which covers bolt pattern compatibility in detail. If you are evaluating whether to repair or replace an aging American Standard toilet, the repair versus replace cost guide provides a break-even framework based on part costs and toilet age.

What Should I Know About American Standard Warranty Coverage for Parts?

The 5-year working parts warranty is one of the more competitive warranties in the mid-range toilet segment. TOTO offers a similar 1-year warranty on working parts with an optional extension, and Kohler's working parts warranty varies by product line. American Standard's inclusion of flush valve seals and fill valves under a 5-year coverage period means that common failure points are protected during the period when they are most likely to fail. For context, the Fluidmaster 400A aftermarket fill valve carries its own 7-year warranty, which may be relevant for homeowners who install aftermarket parts after the American Standard warranty period ends.

For Champion 4 models purchased after 2015, American Standard's warranty documentation specifies that the flush valve tower (part 738310-0070A) is covered under the 5-year parts warranty. If a Champion 4 tower fails within this period, American Standard will ship the replacement tower at no cost to the owner. Retain your purchase receipt or register the toilet at americanstandard-us.com/warranty to facilitate any warranty claim.

OEM Parts Cross-Reference: American Standard vs. Other Brands

Several American Standard tank components share threads or dimensions with parts designed for other brands, which creates partial cross-compatibility in some categories. The fill valve is the most commonly cross-compatible component: the Fluidmaster 400A fits American Standard, TOTO, Kohler (on traditional flapper models), Gerber, and many other brands because its float arm and shank dimensions are designed to the industry-standard dimensions. The Korky 528MP flapper works across multiple 3-inch flush valve seats from American Standard, Kohler, and Gerber. However, flush valve towers -- the component most specific to each manufacturer -- are never cross-compatible between brands, and attempting to install a Kohler canister in an American Standard tank or vice versa will result in incorrect fit and water leakage. The fill valve compatibility is the safe zone for cross-brand substitution; flush valves are brand- and model-specific without exception.

Brands such as TOTO (Drake, Drake II, UltraMax II), Kohler (Highline, Cimarron), Woodbridge (T-0001), Swiss Madison, and Gerber each use their own proprietary flush valve geometry for the same reason -- OEM flush valves are engineered to the specific tank-to-bowl water volume and velocity requirements of each toilet's MaP score. A Kohler AquaPiston canister has a different water release profile than an American Standard Champion 4 tower, and swapping them between toilet brands would compromise flushing performance even if the physical dimensions happened to fit. See our toilet parts diagram guide for a visual breakdown of how these systems differ across brands.