Fluidmaster Duo Flush System-550DFRK-1 - The Home Depot


Model # 550DFRK-1

Internet # 203682806

Store SKU # 570897

Duo Flush System

Fluidmaster Duo Flush System

This item has been discontinued.
The Home Depot no longer carries this specific product.

$23.10 / each


Model # 550DFRK-1

Internet # 203682806

Store SKU # 570897

The Fluidmaster Duo Flush System allows you to quickly convert your existing toilet into a Dual Flush toilet. Duo Flush enables you to use less water by offering two different flush settings, one for liquids and one for solids, and with Duo Flush technology you save water without sacrificing flush performance. Duo Flush replaces the toilet flapper, thus eliminating potential leaks in the future. The DUO FLUSH System also comes with PerforMAX Fill Valve to maximize your toilet performance and water savings. The PerforMAX Fill Valve is the quietest and most powerful fill valve sold.

  • Made of durable corrosion resistant materials
  • Use up to 45% less water
  • Fits more toilets than any other dual flush conversion valve
  • Easy adjust top mounted dials allow for easy water level adjustment and eliminate the need to remove the valve while making adjustments
  • Fits most toilets with a 2 in. flush valve (not compatible with Mansfield or toilets with 3 in. flush valves)
  • Installs in less than 10 minutes with snap-on swivel mount for tool free installation with no tank removal
  • Includes chrome dual action tank lever and all necessary hardware


Assembled Depth (in.)  4.3 in  Assembled Height (in.)  10 in 
Assembled Width (in.)  8.25 in 
Adjustable Fit  Yes, Fill Vale fits most toilets and adjust from 9" to 14" and DUO FLUSH Valve fits toilets with a 2" Flush Valve  Dual Flush  Yes 
Hardware Included  Yes  Includes Flapper  No 
Material  Plastic  Plumbing Part Type  Toilet Flush & Fill Valve 
Returnable  90-Day  Valve Type  Fill 
Warranty / Certifications
Manufacturer Warranty  5 years 


Rated 2.8 out of 5 by 38 reviewers.
Rated 1.0 out of 5.0 by Worst Toilet Valve I have every seen! 2 in two years down the tubes.... I bought this valve hoping It would save a little money, time, and help the environment. WRONG.... This is the second one of these that has broken in less than 2 years. I have seen no savings in water and now I'm sending this one either to a landfill or a recycle center due to the poor quality of the flush mechanism. Both have broken the same way the handle shaft breaks at the tank side that goes into the cable gear head assembly. That is either caused by the cable fraying and causing extra strain on the handle or poor design and quality of the handle material them self. Either way I am converting back to the old style.... a $3.00 flapper and 3 minutes every 5 or 6 years, versus $30.00 twice now and have to undo what was done in 2 years. Long story short I'm out $60.00 plus I will most likely have to buy something else that will cost me 20-30 more February 2, 2015
Rated 5.0 out of 5.0 by Great flushing system ~ easy installation and noticeable different/less water usage The Duo Flush System installation guide is incomparable - complete with specific step by step instructions and pictures to guide through installation process. Uses a noticeably less amount of water and is very quiet too. January 19, 2015
Rated 5.0 out of 5.0 by Easy to install When it came time to replace the tank parts of our guest bathroom toilet, I decided to upgrade to a more water efficient system. When the product arrived, I was a bit unsure of what I was undertaking. However, the installation instructions were very clear and the installation took about 30 minutes to complete. The only tool I used was an adjustable crescent wrench. Everything worked as expected. It is in a second bathroom that gets little use so only time will tell as to the durability issues that others have reported. January 6, 2015
Rated 5.0 out of 5.0 by Definitely saves water and reasonably easy to install and set up Since the State of California just declared a drought we decided to do our bit by upgrading to this water saving Duo Flush system. It comes with a comprehensive set of instructions (including a separate set in Spanish), took about an hour to install and fine tune and definitely saves water. Installation is quite straight forward and doesn't require the removal of the cistern from the toilet base, which is handy. All it took was a wrench to loosen the water supply pipe and a bowl to catch some of the water that drained out when we removed the old fill valve. The Duo Flush is compatible with flat, angled and brass valve seats (the valve seat is where the flapper normally sits) and in our case, we had to use the included angled seat adapter before we could install the unit. The most critical part of the installation is setting the height of the new fill valve when you're installing it - it is recommended to be 3" above the top of the Duo Flush valve. If you simply install the new fill valve without extending its height, the cistern will not fill with enough water, rendering the valve somewhat ineffective for flushing anything away. Setting the valve up is simple and straightforward. The dual action handle that comes with the Duo Flush is pushed upwards for a half flush and downwards for a full flush, and the amount of water used can be easily adjusted for half and full flush using rotary dials on the top of the unit. We marked the high and low water levels while removing the old flush and noticed that the Duo Flush fills the cistern to a level that is about 2-3" lower than the previous high water mark, and when flushing, the low water level is about 2" higher than previously, so its easy to see that the Duo Flush is using less water. March 10, 2014
Rated 5.0 out of 5.0 by I like saving water with this good looking product. This looked real intimidating when I opened the box. But the directions were simple and straight forward. I had it installed in no time. The only thing I saw that was kind of weird is the lever. I have another 2 stage toilet that has 2 push buttons. The lever is a little less intuitive, but it functions very well. This worked really well for me, I have a very old toilet. 1952 with a 5 gallon tank. The mechanism allows you to adjust the level of flush. Now I only use 1 or 2 gallons. I'm figuring this will save over the cost of the unit in about a year. Water is about as expensive as electricity today. August 1, 2014
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