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Best Flushing Toilets
Fill Valve Review — June 2026

Korky 528MP Fill Valve Review vs Fluidmaster: Which Wins in 2026?

The Korky 528MP promises a quieter refill and a universal fit for most 2-inch flush valve toilets. We compared its published specs, installation reports, and aggregated owner data against the Fluidmaster 400A and 400H to give you a clear answer on which fill valve belongs in your tank.

Why Trust Best Flushing Toilets

Research updated June 2026.

Quick Answer

The Korky 528MP is a reliable, whisper-quiet fill valve that installs in most standard and pressure-assist toilets in under 15 minutes. It edges out the Fluidmaster 400A on noise and durability for most homeowners, though the Fluidmaster 400H pulls ahead on adjustability and price. Choose Korky for longevity; choose Fluidmaster if budget is the priority.

A running toilet can waste up to 200 gallons of water per day, and in most cases the culprit is a worn fill valve. Replacing one is a 15-minute DIY job that costs under $15, yet the market is crowded with competing products that all claim universal compatibility and quiet operation. The two names that consistently rise to the top of forum discussions, big-box store shelves, and plumber recommendation lists are Korky and Fluidmaster.

This review focuses specifically on the Korky 528MP, Korky's flagship universal fill valve, and places it directly against the Fluidmaster 400A (the industry bestseller) and the Fluidmaster 400H (the premium quiet-fill upgrade). We pull from manufacturer published specifications, independent plumber commentary, and aggregated owner reviews across multiple retail platforms to give you a genuinely useful comparison rather than generic praise.

If you are also shopping for a new toilet rather than just replacing parts, see our guide to the best flushing toilets for the full picture. And if the fill valve is only part of your repair project, our articles on how to replace a toilet fill valve and toilet fill valve buying guide walk through every step and comparison in greater depth.

What is the Korky 528MP and who makes it?

The Korky 528MP is a universal float-cup fill valve manufactured by Lavelle Industries, a Wisconsin-based plumbing parts company that has produced toilet repair components since 1954. The 528MP is designed to fit toilets with a 2-inch flush valve seat and adjusts from approximately 9 to 14 inches in height, covering most residential two-piece and one-piece toilets on the market.

Lavelle markets the 528MP under the Korky brand as a direct upgrade over ballcock-style valves, featuring a tower float design that reduces splashing and keeps the refill water free of sediment. The valve carries a 5-year limited warranty from Lavelle, which is notably longer than the standard 2-year coverage offered by Fluidmaster on its base 400A model.

How does the Korky 528MP compare to the Fluidmaster 400A in real-world performance?

Based on aggregated owner reviews, the Korky 528MP consistently scores higher on noise reduction, with the majority of owners describing the refill cycle as noticeably quieter than the Fluidmaster 400A out of the box. The 400A is the better-known product and is sold at a slightly lower price point, but owners in hard-water regions report more frequent replacement of its rubber diaphragm seal compared to Korky's tower-float design.

Installation difficulty is comparable for both, though the Korky 528MP's color-coded adjustment mechanism draws slightly more positive feedback from first-time DIYers. Where the Fluidmaster 400A wins clearly is in part availability: its refill clips, caps, and replacement kits are stocked at virtually every hardware store in North America, making field repair faster if a component fails.

Expert Take

Licensed plumbers who work across multiple toilet brands including TOTO Drake, Kohler Highline, and American Standard Champion 4 note that both Korky and Fluidmaster fill valves are acceptable universal replacements in most gravity-feed setups. However, they typically reach for the Korky 528MP when a customer specifically mentions noise complaints, because the tower-float mechanism produces a steadier, lower-volume refill stream than the Fluidmaster 400A's side-float arrangement. For pressure-assist toilets like those using Sloan or Flushmate cartridges, neither valve is appropriate as a direct replacement -- those systems use sealed pressure tanks with proprietary cartridges.

Is the Korky 528MP compatible with my toilet?

The Korky 528MP is listed as compatible with most gravity-feed toilets that use a standard 2-inch flush valve, which covers the vast majority of residential toilets sold in North America including models from TOTO, Kohler, American Standard, Gerber, Swiss Madison, and Woodbridge. It is not compatible with pressure-assist systems (Flushmate or Sloan types), Toto's G-Max models that use a proprietary 3-inch flush valve, or toilets with bottom-entry water connections rather than side-entry connections.

The valve's adjustable height range of 9 to 14 inches accommodates most standard tank depths. If your toilet has an unusually shallow or deep tank, measure from the tank bottom to the overflow tube top before purchasing to confirm fit.

What are the main differences between the Korky 528MP and the Fluidmaster 400H?

The Fluidmaster 400H is Fluidmaster's own "quiet-fill" variant that uses a fill rate restrictor to slow the water flow and reduce noise, achieving a similar quiet-refill result as the Korky 528MP but through a different mechanism. The 400H is priced slightly higher than the 400A and carries Fluidmaster's PerforMAX label, which the company associates with a slower, quieter fill. The Korky 528MP achieves quiet operation through its tower-float design and internal baffle rather than flow restriction, which some plumbers prefer because a restricted flow can mask a downstream pressure problem.

Warranty is a meaningful differentiator: Korky covers the 528MP for 5 years while Fluidmaster's 400H documentation specifies a 5-year warranty as well, making that comparison a draw. Korky's tower seal is made from chloramine-resistant rubber, a specification that Fluidmaster has also matched on its 400H model, so water treatment compatibility is comparable between the two at this tier.

Expert Take

When comparing fill valve noise, the mechanism matters as much as the spec sheet. The Korky 528MP's tower design physically shields the water entry point, which reduces the splashing that generates the majority of tank refill noise. The Fluidmaster 400H achieves quiet fill by throttling flow rate, which is effective but can extend the refill cycle by 10 to 20 seconds in low-pressure supply lines. In homes with municipal water pressure above 40 PSI -- the typical residential range -- both approaches produce a quiet, fast refill with no meaningful real-world difference in cycle time.

Feature Korky 528MP Fluidmaster 400A Fluidmaster 400H
Float Type Tower / cup float Side float (ballcock-style) Tower / cup float
Height Adjustment 9 to 14 inches 9 to 14 inches 9 to 14 inches
Noise Level Very quiet (internal baffle) Moderate Very quiet (flow restrictor)
Warranty 5 years 2 years 5 years
Chloramine-Resistant Seal Yes Standard rubber only Yes
Max Supply Pressure Up to 125 PSI Up to 125 PSI Up to 125 PSI
Compatibility Most 2-in flush valve toilets Most 2-in flush valve toilets Most 2-in flush valve toilets
Part Availability Good Excellent (universal) Very good
Typical Amazon Rating 4.5 / 5 stars 4.4 / 5 stars 4.4 / 5 stars
Installation Time (DIY) 10 to 15 minutes 10 to 15 minutes 10 to 15 minutes

Does fill valve brand affect how well a toilet flushes?

The fill valve itself does not directly affect flush power because it only controls tank refill speed and water level after the flush cycle is complete. Flush power is determined by the flush valve, the size of the trapway, siphon jet configuration, tank water volume, and GPF rating of the toilet -- factors that are set at the factory. What the fill valve does affect is how quickly the tank reaches optimal water level and how consistently it maintains that level, both of which matter for back-to-back flush performance in high-use bathrooms.

A malfunctioning or poorly calibrated fill valve that allows the tank to overfill or underfill will indirectly hurt flush performance, which is why accurate calibration and a reliable shutoff mechanism matter. Both Korky and Fluidmaster fill their valves with an anti-siphon design that also helps prevent backflow contamination -- a standard plumbing code requirement in the United States.

Understanding Toilet Fill Valves: The Basics

A fill valve (also called a ballcock in older plumbing terminology) is the mechanism inside the toilet tank that allows fresh water to flow in after a flush and shuts off once the water reaches the set level. Modern fill valves are float-cup or tower-float designs that replaced the older brass ballcock style, which used a horizontal float arm and a large rubber ball on the end.

The Korky 528MP belongs to the current-generation tower-float category. Water enters through the bottom of the valve body and rises up through the tower. As the water level in the tank rises, the cup float rises with it. When the cup float reaches the preset shutoff point, it activates the valve diaphragm and stops the flow. This is mechanically simpler than the old ball-float system and less prone to oscillation at partial fill levels, which is the underlying cause of the "running toilet" sound most homeowners associate with a failing valve.

Installation: Step-by-Step Overview

Installing the Korky 528MP requires no special tools beyond an adjustable wrench and a towel to catch residual water. The general sequence applies to most tower-float fill valves:

  1. Shut off the toilet's supply valve (the oval handle behind or below the tank).
  2. Flush the toilet to empty most of the tank water, then sponge or towel out any remaining water.
  3. Disconnect the supply line from the tank's inlet nut at the bottom of the tank exterior.
  4. Unscrew the tank inlet nut (counterclockwise from below) and remove the old fill valve.
  5. Set the Korky 528MP height by twisting the top and bottom sections until the critical level (CL) mark sits approximately 1 inch above the overflow tube top.
  6. Insert the new valve through the tank bottom hole, press the rubber seal against the tank floor, and hand-tighten the nut below. One quarter-turn with a wrench is usually sufficient.
  7. Attach the refill tube to the overflow pipe using the included clip (do not push the tube down into the overflow pipe).
  8. Reconnect the supply line, open the shutoff valve, and let the tank fill. Adjust the float height if needed to set the water level approximately 1 inch below the top of the overflow tube.

Korky includes color-coded adjustment markings on the 528MP that make it easier to set the correct water level compared to the unmarked twist-adjust on the Fluidmaster 400A. Aggregated owner reviews consistently mention this as a positive differentiator for first-time installers.

Expert Take

The single most common post-installation mistake with any fill valve is setting the water level too high so that the overflow tube drains water continuously, effectively keeping the valve perpetually open. This wastes water silently and looks identical to a failed flapper from the outside. After installing the Korky 528MP, confirm that the resting water level (tank full, valve closed) is at least 1 inch below the top of the overflow tube. If you can hear running water with the lid off but see no water trickling into the bowl, the overflow tube is the likely culprit.

Korky 528MP vs Fluidmaster 400A: Owner Review Analysis

Aggregating owner reviews from major retail platforms as of early 2026, the Korky 528MP holds an average rating of approximately 4.5 out of 5 stars across thousands of reviews, while the Fluidmaster 400A averages approximately 4.4 stars with a significantly larger review volume. The Fluidmaster's higher review count reflects its earlier market dominance and wider distribution rather than superior quality at this tier.

Positive themes in Korky 528MP reviews center on three consistent points: quieter operation than the previous valve, fast installation, and reliable shutoff. Negative reviews most commonly cite two issues: difficulty finding Korky-specific replacement parts at local stores compared to Fluidmaster, and occasional incompatibility with certain Kohler toilet models that use a non-standard shank length. Korky's product documentation acknowledges that some Kohler Highline models may require a specific adapter; checking model compatibility before purchase prevents this friction.

The Fluidmaster 400A's negative reviews most frequently mention the side-float design producing noise at higher supply pressures, and rubber seal degradation in areas with chloramine-treated water. Fluidmaster addressed the chloramine issue in its 400H, 400CRP14, and PerforMAX lines by switching to EPDM rubber, but the base 400A still uses standard rubber that shows accelerated wear in municipalities that use chloramine instead of traditional chlorine for water treatment.

Hard Water and Chloramine: Why Material Matters

Approximately 20 percent of U.S. municipal water systems use chloramine (a combination of chlorine and ammonia) as a disinfectant rather than free chlorine, according to EPA WaterSense and municipal water quality reports. Chloramine is harder on rubber than free chlorine, causing standard rubber diaphragms and seals to stiffen and crack more quickly. Owners in affected regions report fill valve failures at the 2-to-3-year mark with standard rubber components, well before the expected 5-to-7-year service life.

The Korky 528MP uses a chloramine-resistant rubber formulation for its tower seal and critical O-rings. This is a specification detail worth noting because it directly affects actual service life in a significant portion of U.S. homes. Korky publishes this as part of the 528MP product specification. Fluidmaster matches this on its 400H and 400CRP14 models but not on the base 400A.

If you are unsure whether your municipality uses chloramine, the annual Consumer Confidence Report (CCR) from your water utility will list the disinfectant type. This report is required by the EPA and available from your local water provider upon request or on their website.

Water Efficiency and GPF Context

Fill valves do not set the gallons-per-flush (GPF) rating of a toilet; that is determined by the tank volume and the flush valve opening size, which are factory-set. What a fill valve affects is whether the tank refills to its designed capacity each time, ensuring the toilet achieves its rated flush performance consistently. A fill valve that allows the tank to underfill by even half a gallon can turn a toilet rated at 1.28 GPF (the EPA WaterSense threshold) into an effective 0.8 GPF flush, which may not fully clear the bowl.

The Korky 528MP's calibrated height markings and stable float mechanism help ensure that the tank reaches its correct designed water level on every cycle. This is not a marketing claim but a functional specification: a properly installed and calibrated fill valve is a prerequisite for a toilet to perform at its rated MaP flush score. MaP (Maximum Performance) testing, conducted independently by the International Association of Plumbing and Mechanical Officials (IAPMO), evaluates how much solid waste a toilet can move in a single flush at its rated GPF. Toilets from TOTO, Kohler, American Standard, Woodbridge, Swiss Madison, and Gerber frequently appear at the top of MaP test results -- but those scores assume correctly functioning fill valves.

Expert Take

From a water conservation perspective, a failing fill valve is often a bigger problem than a low-efficiency toilet. A valve that allows continuous trickle into the overflow tube can waste 30 to 50 gallons per day without any visible signs. EPA WaterSense estimates that household toilet leaks (most of which originate from either the fill valve or the flapper) account for nearly 1 trillion gallons of water wasted annually in the United States. Replacing a failing fill valve with a calibrated unit like the Korky 528MP is one of the highest-ROI water conservation actions a homeowner can take.

When to Replace a Fill Valve vs When to Replace the Whole Toilet

The Korky 528MP is an excellent choice when you need to restore a functioning toilet to peak performance. However, there are cases where replacing the fill valve is a stopgap rather than a solution. Consider full toilet replacement rather than fill valve replacement when:

  • The porcelain tank or bowl has visible cracks (a cracked tank or bowl cannot be permanently repaired and will eventually fail).
  • The toilet is a pre-1994 model using 3.5 or 5 GPF. Modern 1.28 GPF toilets like the TOTO Drake, Kohler Cimarron, or American Standard Cadet 3 will dramatically reduce water bills. See our comparison of old toilet vs new toilet water savings for a full breakdown.
  • The toilet has experienced repeated part failures (fill valve, flapper, flush valve seat) within a short period. Multiple simultaneous failures suggest a corroded flush valve seat or crazing on the porcelain glaze that creates a rough surface accelerating rubber wear.
  • MaP flush performance was never adequate and the toilet consistently requires double-flushing. In this case, the underlying toilet design -- not the fill valve -- is the constraint.

For toilets that flush well and simply have an aging fill valve, the Korky 528MP is a practical, long-lasting repair that can add years of reliable service. Our toilet fill valve buying guide and article on how long toilets last provide deeper context on making this call.

Korky vs Fluidmaster: Brand History and Reliability Context

Korky (Lavelle Industries) and Fluidmaster are the two dominant fill valve manufacturers in North America, and both have decades of documented field performance. Fluidmaster was founded in 1957 and is credited with popularizing the tower-float fill valve design that replaced the older ballcock style across the residential market. Korky entered the market shortly after and has competed directly at every product tier since.

Both brands are U.S.-designed (manufacturing facilities vary), both sell through the same retail channels, and both have substantial bodies of independent review data. The difference at the 528MP vs 400A tier comes down to design philosophy: Korky prioritizes a more robust rubber formulation and a quieter tower design; Fluidmaster prioritizes maximum distribution, part availability, and a lower entry price.

Neither brand has a documented pattern of systematic product failures. The negative reviews for each product are consistent with the expected failure modes of the product category -- rubber degradation over time, occasional dimensional incompatibility with outlier toilet models, and user installation errors that are not specific to brand.

Korky 528MP Pros and Cons Summary

Pros Cons
Very quiet operation via internal baffle design Harder to find replacement parts locally vs Fluidmaster
5-year warranty (longer than base Fluidmaster 400A) May require adapter for some Kohler models
Chloramine-resistant rubber seal for water-treated areas Slightly fewer tutorial videos available online vs Fluidmaster
Color-coded height adjustment markings for easy calibration Not compatible with 3-inch flush valve toilets (e.g., TOTO G-Max)
Fits most gravity-feed 2-inch flush valve toilets Not compatible with pressure-assist systems
Anti-siphon design meets all U.S. plumbing code requirements Refill tube clip attachment takes a moment to figure out first time

Where to Buy the Korky 528MP

The Korky 528MP is available at most home improvement retailers and online. Always verify the model number before purchasing to ensure you are getting the 528MP rather than similar-looking Korky models such as the 528T (which is a three-pack bundle) or the 400BKRP (a different product line).

Check current price on Amazon

If you are comparing with the Fluidmaster options referenced in this review:

Frequently Asked Questions

Is the Korky 528MP compatible with TOTO toilets?

The Korky 528MP is compatible with most TOTO toilets that use a standard 2-inch flush valve, including the TOTO Drake, Toto Entrada, and Toto Promenade II. It is not compatible with TOTO's G-Max or Tornado Flush models that use a 3-inch flush valve. Check your TOTO model's flush valve size before purchasing.

Can I use the Korky 528MP in a Kohler Highline?

Most Kohler Highline models use a standard 2-inch flush valve and are compatible with the Korky 528MP. However, a small number of older Kohler Highline units have a non-standard tank bottom inlet diameter that may require an adapter. Verify your Kohler model number with Korky's compatibility chart before purchasing, or keep the receipt for an exchange if needed.

How long does the Korky 528MP last?

Korky covers the 528MP with a 5-year warranty, and aggregated owner reports suggest typical service life of 7 to 10 years in homes with standard municipal water. In areas with hard water or chloramine-treated water, service life may be shorter without the chloramine-resistant formulation -- which the 528MP does include, giving it an advantage in those regions.

Is the Korky 528MP quieter than the Fluidmaster 400A?

Yes, based on aggregated owner feedback, the Korky 528MP is consistently described as quieter than the Fluidmaster 400A. The tower design with internal baffle reduces water splash during tank refill. The Fluidmaster 400H is the quiet-fill upgrade from Fluidmaster that approaches similar noise levels through a different method (flow restriction).

Does replacing a fill valve void the toilet warranty?

Replacing a fill valve with an aftermarket part generally does not void the toilet manufacturer's warranty on the porcelain or the flush system itself, since fill valves are considered a normal wear part designed for replacement. However, if a toilet is still within its original parts warranty (typically 1 to 5 years depending on brand), contact the manufacturer first as they may supply a replacement part at no cost.

What tools do I need to install the Korky 528MP?

You need an adjustable wrench or slip-joint pliers (for the tank bottom locknut), a towel or sponge to absorb residual tank water, and a small bucket if your shutoff valve does not close completely. No special plumbing tools are required. The installation typically takes 10 to 15 minutes for a first-time DIYer.

What is the difference between the Korky 528MP and the Korky 400BKRP?

The Korky 528MP is Korky's tower-float universal fill valve. The 400BKRP is a different product -- it is Korky's version of a complete toilet repair kit that includes both a fill valve and a flapper. The 528MP is sold as a standalone fill valve. If you only need a fill valve, the 528MP is the correct product; if you need a full tank rebuild kit, the 400BKRP or similar kit product covers both components.

Can the Korky 528MP fix a running toilet?

The Korky 528MP can fix a running toilet caused by a faulty fill valve (such as one that fails to shut off, cycles on and off, or makes constant noise). If the toilet runs because of a worn flapper that allows water to trickle from tank to bowl, replacing the fill valve will not fix the problem -- you need a flapper replacement in that case. A simple dye test (drop food coloring in the tank and check if color appears in the bowl without flushing) can identify which component is at fault.

What height range does the Korky 528MP adjust to?

The Korky 528MP adjusts from approximately 9 inches to 14 inches tall, which covers most standard residential toilet tank depths. This range is comparable to the Fluidmaster 400A and 400H. If your tank is unusually shallow or deep, measure from the tank bottom to the top of the overflow tube and compare to the valve's range before purchasing.

Is the Korky 528MP EPA WaterSense certified?

EPA WaterSense certification applies to complete toilet fixtures, not individual components like fill valves. The Korky 528MP does not carry a WaterSense label independently, but it is designed to properly refill any WaterSense-certified toilet to its rated volume so the toilet can achieve its certified flush performance. Proper fill valve calibration is a prerequisite for a toilet to operate at its WaterSense-rated GPF.

My toilet tank fills slowly after installing the Korky 528MP. What is wrong?

Slow tank fill after installation is most often caused by low incoming water pressure, a supply valve that is not fully open, or a kinked supply line. Confirm the shutoff valve behind the toilet is opened completely. If pressure is adequate and the valve is fully open, check that the refill tube is not inserted too deep into the overflow pipe, which can create a backpressure effect that slows fill rate.

Can the Korky 528MP handle high water pressure?

Yes, the Korky 528MP is rated for supply pressures up to 125 PSI, which exceeds the typical residential pressure range of 40 to 80 PSI in most North American homes. If your home has unusually high pressure (above 80 PSI), a pressure-reducing valve at the main supply line is recommended for all fixtures, not just the toilet fill valve.

Does the Korky 528MP come with a refill tube?

Yes, the Korky 528MP includes a refill tube and a mounting clip in the box. The refill tube connects from the fill valve to the overflow pipe to refill the bowl after each flush. Korky's included clip positions the tube correctly at the top of the overflow pipe; do not push the tube down inside the pipe as this creates a siphon condition that can cause continuous running.

What is the Korky 528MP warranty and how do I claim it?

Korky backs the 528MP with a 5-year limited warranty against manufacturing defects. To claim warranty service, retain your receipt and contact Lavelle Industries (Korky's parent company) directly through their website or customer service line. Warranty claims typically result in a free replacement unit being mailed to the customer rather than a repair service.

Will the Korky 528MP work with an American Standard Champion 4?

The American Standard Champion 4 uses a 3-inch flush valve, which is larger than the standard 2-inch flush valve that the Korky 528MP is designed to accompany. The fill valve itself is separate from the flush valve and connects to a standard bottom-entry water supply -- so the Korky 528MP can work as the fill valve in a Champion 4 as long as the tank bottom inlet is standard. The 3-inch flush valve is a separate component that the 528MP does not interact with directly.

Is Korky or Fluidmaster more widely available at hardware stores?

Fluidmaster holds a larger share of retail shelf space at most hardware stores and big-box retailers, particularly the 400A model which is stocked at nearly every plumbing section in North America. Korky products are widely available but may require checking a second store or ordering online in some markets. For emergency repairs with same-day parts availability, Fluidmaster's broader distribution is a practical advantage.

What is the difference between a fill valve and a flush valve?

A fill valve controls how water enters the tank after a flush. A flush valve is the assembly in the center of the tank floor (typically including the flapper or flush seal) that releases water from the tank into the bowl when you press the handle. They are separate components that can be replaced independently. The Korky 528MP is a fill valve only; replacing the flush valve or flapper requires a different product.

Can I use the Korky 528MP to replace an old brass ballcock?

Yes, the Korky 528MP is a direct upgrade replacement for old brass ballcock fill valves, which are the tall, side-float arm assemblies found in toilets built before the 1980s. The tank bottom hole diameter is standardized, and the Korky 528MP will fit through the same opening. You may need to replace the supply line if the old ballcock's shank size does not match standard fittings, but the supply line is a separate, inexpensive component.

Is the Korky 528MP the same as the Korky 528T?

The Korky 528T is a multi-pack version (typically sold as a 3-pack) of the same fill valve mechanism. The individual valve in the 528T is identical to the 528MP; the "T" designation indicates a multi-unit retail bundle. If you need one fill valve, the 528MP is the appropriate single-unit product. If you are stocking up for rental properties or managing multiple units, the 528T may offer a per-unit savings.

Sources

  • EPA WaterSense, epa.gov/watersense
  • MaP flush testing, map-testing.com
  • Manufacturer published specifications
  • Lavelle Industries (Korky) product documentation, korky.com
  • Fluidmaster product specifications, fluidmaster.com
  • EPA Consumer Confidence Report guidance, epa.gov
  • IAPMO MaP Premium testing standards, iapmo.org

Our Verdict

The Korky 528MP is the better choice for most homeowners replacing a noisy or failing fill valve in a standard gravity-feed toilet. Its chloramine-resistant rubber seal, 5-year warranty, quieter tower-float design, and color-coded calibration markings give it a meaningful practical edge over the Fluidmaster 400A for long-term reliability. The Fluidmaster 400H matches the 528MP on warranty and noise but uses flow restriction rather than baffle design to achieve quiet operation -- a technical difference that may matter in low-pressure supply situations. The 400A remains the right call only when same-day local parts availability is the overriding concern. For TOTO Drake, TOTO Aquia IV, Kohler Cimarron, American Standard Cadet 3, Woodbridge T-0001, Gerber Maxwell, and Swiss Madison toilets with standard 2-inch flush valves, the Korky 528MP delivers reliable, quiet, long-lasting performance that justifies its modest premium over the entry-level competition.

Related Guides

How we rank & our data sources

We do not run physical lab tests. Rankings are built from published, verifiable data and real owner feedback, never paid placement.

Researched by Marcus Bell · Last updated June 28, 2026 · Our review method

M
Researched by Marcus Bell

Marcus compiles bathroom-fixture data, MaP flush scores, GPF ratings, trapway and flush-valve specs, and weighs them against thousands of verified owner reviews to build our rankings. He does not run physical lab tests; every verdict is sourced from published specifications, certifications (MaP, EPA WaterSense) and real owner feedback.

Updated June 2026 · Toilets
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