Evan Matzen, Manager, Sustainability


Megan Clifford, Senior Sales and Marketing Specialist at Korky®, is back this week to walk us through fill valves and how to conserve even more water.


Evan Matzen: How do I select the right fill valve for a toilet?

Megan Clifford: For a long time, fill valve selection was pretty standard. However, many newer toilets require a fill valve that allows for adjustment of toilet bowl water.

Follow this selection guide to select the correct fill valve for most toilets:

Age of Toilet HDS Part Product Name Image
1994 and older 575265 Korky® QuietFILL® flapper_1
Ideal for newer toilets made since 1994; optimizes water usage in any toilet 579001 Korky® MaxPERFORMANCE® flapper_2


Why a different valve for newer toilets? Pre-1994 toilets send a standard amount of water to the toilet bowl through the flush valve overflow tube (about 20%). Accordingly, most aftermarket fill valves send about 20% of water to the toilet bowl. However, newer 1.6 and 1.28 GPF toilets can send anywhere from 0 to 40% of incoming water to the toilet bowl. If an OEM fill valve with a low or high refill specification is replaced with a standard 20% valve, the toilet will either waste water or under-fill the bowl, resulting in poor flushing performance.

The MaxPERFORMANCE® valve addresses this variation amongst toilet models with a refill adjustment, which allows matching of the toilet’s OEM settings. By matching the OEM refill ratio, a 1.6 or 1.28 toilet will operate with maximum performance and water efficiency. This valve can also be used to optimize older toilets as well. See a video aboutMaxPERFORMANCE® here.

E: So are there things that I can do to my existing toilet to reduce water consumption without impacting its ability to flush?

M: We suggest installing an adjustable product. This will allow you to fine-tune water usage to find that balance between less water and adequate performance. Follow this chart to select the best adjustable product for the toilet you have or are servicing:


Part Age of toilet Flush valve size HDS Part Product Name
Flapper Before 1994 2” flush valve 579320 Korky® Plus Adjustable
Flapper After 1994 2” flush valve 579509 Korky® Plus 1.6
Flapper 1997 and newer 3” flush valve 579522 Korky® Universal 3” Flapper
Fill Valve All toilets N/A 579001 NEW! Korky®MaxPERFORMANCE®


E: Can I do anything to prevent leaks?

M: A way to protect from water waste is to “insure” the toilet in the case that the flapper does leak. Install the smartest valve on the market: The Korky® WaterWI$E® Fill Valve for dual leak protection.

  1. The first kind of leak is a slow flapper leak. The valve will remain off in this scenario and will not continue to run intermittently like a non-leak detecting fill valve would.
  2. Secondly, WaterWI$E® is the only valve that will protect from a severe leak. In this scenario, the toilet is running non-stop due to a flapper hang-up or a sticky flush lever. WaterWI$E® is the only toilet fill valve with a self-shutoff feature to protect against this type of wasteful water spike!

If a leak is detected, the consumer will be signaled by WaterWI$E® because the toilet tank will be empty. In the case of a leak, the valve has a convenient reset feature, which allows for continued use until the leak has been fixed. Check out this video about WaterWI$E®.

E: What does Korky® do to promote water conservation?

M: Since inventing the flapper in the 1950s, Korky® has led the way in terms of toilet repair technology. In 1990, Korky® revolutionized the industry again by introducing the first chemical-resistant flapper. Since then, we have been advocates of saving water by installing a durable, chemical resistant flapper to protect from flapper leaks, the No. 1 water waster in the home. As municipal water supplies continue to change, we continue to improve our material and engineer for performance that will resist the modern-day water supply and drop-in tank cleaners.

E: What kind of water conservation products do you use in your own home?

M: It is not surprising, but our team at Korky® all has products in our own toilets to save water. I personally have a Korky® adjustable flapper installed to minimize GPF, and a WaterWI$E® fill valve in case a leak does occur. Other members of our team have also upgraded to 1.28 GPF toilets as another great way to save water.


Do you do anything else to promote water conservation on your property or at your home?


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