Toto Guinevere: replacing flush valve

Discussion in 'Toilet Forum discussions' started by gdr128, Oct 10, 2017.

  1. gdr128

    gdr128 New Member

    Joined:
    Oct 10, 2017
    Location:
    Los Angeles
    I'm wondering if I can substitute a drain valve for a flush valve on my toilet.

    I have three four-year old Toto Guinevere (MS974224cefg) -- a terrible toilet. The flapper leaks, and the trip lever breaks; I've been through several of each. Two now sound like they're flushing themselves -- time for new flappers.

    I looked online, and it appears that there is now a "drain valve" that can be substituted for the "flush valve." I thought maybe that would solve the frequent-leak problem. But I'm wondering if the drain valve will work in the model toilet I have. I called Toto tech support, and they said no, a drain valve will not work in my toilet, so I need a new flapper. My question is: are they right, or would a drain valve in fact work in my model Toto Guinevere? (They said that the new flapper they have, the THU500, works better. Of course I'm skeptical -- of everything Toto says.)

    Thank you!
     
  2. Reach4

    Reach4 Well-Known Member

    Joined:
    Sep 25, 2013
    Location:
    IL
    Maybe try a Fluidmaster flapper?

    I don't find any references to a THU500 flapper.
     
    Last edited: Oct 10, 2017
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  4. wjcandee

    wjcandee Wise One

    Joined:
    Apr 27, 2012
    Location:
    New York, NY
    Your experience isn't the norm, either for the Guinevere or for the Toto line in general, so your "skepticism" may be misplaced. Maybe there's something we can uncover that would help you.

    First, flappers do deteriorate over time, but not usually at the speed you are describing. Are you using an in-tank bowl cleaner, like 1000 Flushes or similar? That will degrade a flapper ricky-tick. There are some automatic cleaner setups that can bypass the tank.

    And while we occasionally see discussions about the trip levers on the Drake, it's not the norm to see someone going through 2 trip levers in 4 years. That plus the flapper issue makes me wonder whether someone is being a bit of a gorilla with it. If not, its just bad luck.

    What's Toto is calling a "drain valve" is really just another form of flush valve; it is however a tower design rather than a flapper design. In a one-piece, the flush valve is installed a little differently than a 2-piece (because there is no detachable tank, so you have to have a design that is removable and installable from inside the "tank"); I guess they haven't made a tower version for the Guin.

    Which replacement flapper are you using? Maybe we can suggest one that's a little more durable.
     
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  5. gdr128

    gdr128 New Member

    Joined:
    Oct 10, 2017
    Location:
    Los Angeles
    Thanks very much for the replies. I very much appreciate the interest and the help.

    1. I don't know why the flappers are failing. I don't use any in-tank cleaners. I just use normal toilet bowl cleaner periodically, as needed. Oh well.

    2. Thank you for the flush valve vs drain valve clarification. That really helps. I have done some research, and here's what I've come up with.

    a. The man at Toto technical support told me that I can't use a drain valve, but rather must use a flush valve. He said to buy THU451.10A-a. That, though, is just the kind of flapper-less one-piece unit you mentioned above.

    b. I looked on plumbingsupply.com, and that appears to be incorrect. That website shows that valve is I should use a THU453.6B-A. The latter is for the eco version of the Guinevere, which is what I have. The one Toto's person recommended is for the Ultramax -- not the Guinevere -- and the 1.6 gpf, not the eco 1.28 gpf. So, it seems that putting in the THU 453.6B-A will solve my problem, because it will get rid of the whole flapper issue.​

    Right?

    Links used:
    https://www.plumbingsupply.com/tototoiletparts-guinevere.html
    https://www.plumbingsupply.com/tototoiletparts-ultramax.html
     
  6. jadnashua

    jadnashua Retired Defense Industry Engineer xxx

    Joined:
    Sep 2, 2004
    Occupation:
    Retired Systems engineer for defense industry.
    Location:
    New England
    FWIW, the water chemistry makes a big difference in the life of most any rubber components. Have your own well, a flapper valve may last a decade or more...have highly chlorinated water, maybe a year or two. The Korky units do have a warranty, so if you go that way, keep the receipt.
     
  7. wjcandee

    wjcandee Wise One

    Joined:
    Apr 27, 2012
    Location:
    New York, NY
    Well I have to say I'm impressed. I didn't think to look past Toto Customer Service's comments to you because they are usually very good and knowledgeable, and let you talk to an engineer if your question is really complicated.

    But I'm glad you did!

    To confirm what you were told elsewhere, here is the current parts list for your Guin. https://www.totousa.com/filemanager_uploads/product_assets/PD-00529_MS974224CEFG.pdf

    Item 8 is the flush valve and gaskets and such, all in a little kit. So they DO now make a flush tower for the thing. And you got the model number right. If you google that number, some places have it for less than $20 with free shipping.

    Good luck! Let us know how it goes!
     
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