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501P21 Universal Flapper with Microban (Red/Black)
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$3.46 each
BOX UP & SAVE 4%
$69.51 box of 21
$3.31 each
In Stock
Order by 6PM, receive Tomorrow
This item replaces: 501R3P8, 501CT
Free Shipping On orders over $99
Easy Returns No restocking fee for 90 days
Description
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Fluidmaster 501P21 Universal Flapper with Microban (Red/Black)
A Fluidmaster universal toilet flapper replacement used to seal most 2" flush valves and stop a running toilet by restoring a reliable tank-to-bowl seal.
Key Features
Compatibility & Applications
Installation & Operation Notes
Maintenance & Troubleshooting
User Reviews & Q&A Summary
A Fluidmaster universal toilet flapper replacement used to seal most 2" flush valves and stop a running toilet by restoring a reliable tank-to-bowl seal.
Key Features
- Universal fit for most 2" flush valves (solid-frame flapper design)
- Built-in Microban® protection (built into the flapper construction, not just a coating)
- Chlorine- and hard-water-resistant materials (manufacturer guidance)
- Solid frame helps prevent twisting to maintain a consistent seal (manufacturer guidance)
- Kink-free chain (manufacturer guidance)
- Manufacturer notes it is best suited for older toilets, 3.5 GPF or more (pre-1994)
- Manufacturer warning: Do not use in-tank drop-in toilet bowl cleaners containing bleach or chlorine (can damage tank components)
Compatibility & Applications
- Intended for toilets using a 2" flush valve where a solid-frame universal flapper is appropriate (manufacturer describes it as fitting most 2" flush valves).
- SupplyHouse notes this item replaces: 501R3P8 and 501CT.
- Must only be used where the manufacturer specifies this exact part number: 501P21.
Installation & Operation Notes
- Installation can typically be performed by a plumber, maintenance technician, or experienced DIYer.
- Follow the toilet manufacturer's service instructions for safe tank access and correct chain length/positioning.
- Avoid in-tank drop-in cleaners containing bleach/chlorine per manufacturer warning.
Maintenance & Troubleshooting
- A worn flapper is a common cause of running toilets, "handle jiggling," or intermittent leaking into the bowl; replacing the flapper is a standard corrective step when the flush valve seat is otherwise intact.
- If a toilet still runs after replacement, confirm correct fit on the 2" flush valve, proper chain slack, and that the flapper is seating flat and not being held open by the chain or interference.
User Reviews & Q&A Summary
- Stops running toilets / reliable seal: Reviewers frequently report it resolves running-toilet issues and seals well.
- Longevity/value: Many comments describe it as long-lasting and a good value compared to other flappers they tried.
- Best for older/high-volume toilets: Multiple reviews specifically call it their preferred choice for older
- Hard-to-find locally: Some reviewers mention it was difficult to source elsewhere and stocked up once they found it.
Specs
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| Type: | Flapper |
|---|
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Product Reviews
5 out of 13 reviews
100% would recommend this product
5 star
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Showing 1-10 of 13 reviews
Flusher fix kit
Fix kit is great when I need to break off supports on tilt valves
Marty
Cranford NJ
2 years ago
Verified Buyer
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No more toilets running
I've used these toilet flappers for years. They last a long time, and the price these folks had couldn't be beat.
pp15933
Home
4 years ago
Verified Buyer
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Good value
These seem to seal good and they last.
Darrel H
Ohio
6 years ago
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Fixed my issue
Easy fix, took out the old and replace it. Easy Peezy
Do It Myself
Shelbyville, KY
6 years ago
Verified Buyer
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The only toilet flapper I would use in my pre-1994 toilets.
Best Toilet Flapper for most pre-1994 toilets.
N/A
Madison, AL
6 years ago
Verified Buyer
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I would buy this product again
Good price, fast delivery, and good quality, thanks
Lee
Houston Tx
8 years ago
Verified Buyer
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Excellent customer service
Super fast order processing and shipment, very reasonable prices and shipping costs. Great company !
JCR
New York, NY
9 years ago
Verified Buyer
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Works Great With My Set Up
I originally had the system with this flapper. When that flapper wore out I tried several others until I found one like this. With the others I needed to hold the handle down until all the water drained or they would close. My replacement flapper recently wore out. I searched online for this one and it was hard to find. Then I found it on Supply House at the best price. I ordered a bunch of them in case I couldn't get them in the future. I ordered on a Sunday night and had them Tuesday afternoon. Now I will always check Supply House for items I need. Great transaction!
MVD
Hauppauge, NY
9 years ago
Verified Buyer
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great buy
works great ,easy install
russ
Bonita Springs , Fl
10 years ago
Verified Buyer
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hard to find product in stores. you had it in stock
part was in stock and shipped within one day
bob
lancaster, pa
10 years ago
Verified Buyer
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Free Shipping
On orders over $99
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