Need to install two new toilets, back to back issue

Discussion in 'Toilet Forum discussions' started by BruceG, Dec 4, 2010.

  1. BruceG

    BruceG New Member

    Messages:
    3
    Location:
    San Jose CA
    We are doing a remodel and will replace two older Toto toilets. They are back to back connected with a "T". I was going to install newer Toto toilets but due to our "T" connection Toto won't support it. I researched American Standard and Kohler and their support reps have said the same thing - they won't perform in a back to back with a "T". Our plumber has told us that to change out the T would be a substantial amount of work (and cost).

    I've seen some postings in this forum that indicate that while it's not ideal, it can be done with some possible issues.

    Two questions:

    Realistically, what type of issues could we expect?

    Second, which brand/model would best the least problematic in this config? We do need ADA height, and would like to stick with a major brand where replacement parts won't be a problem down the road. We'd like to keep the price reasonable, but do want decent quality.

    One suggestion was a Kohler model with their Ingenium flushing system but from what I can read that's not an especially good toilet - hate to install something I know in advance won't work well.

    Thanks in advance for any help.

    Bruce
  2. jadnashua

    jadnashua Retired Defense Industry Engineer xxx

    Messages:
    22,023
    Location:
    New England
    To flush with the mandated smaller water use, ANY toilet needs to flush much faster than the old styles. I don't think any of them will work properly with a simple T between them. What will happen is the jet of water created when they flush will flow across and cause splashing in the other toilet, not a good situation, especially if you're sitting there! time to bite the bullet and change it out to the specified fitting.
  3. BruceG

    BruceG New Member

    Messages:
    3
    Location:
    San Jose CA
    Jim,

    Thanks for your feedback. The cost to make the change is steep as it involves a lot of redoing of the piping - it's not a simple switch of the connection unfortunately.

    We can certainly ensure we don't use both toilet at the same time to avoid any issues - if that's the only problem we'll live with it. I'm interested to know if that's the extent of the problem, and if there are any toilets currently that might be less prone to cause a problem. One that might not be as powerful as the new Toto for example, but would do a better job than the Kohler with the known issues.

    Thanks,
    Bruce
  4. Gary Swart

    Gary Swart In the Trades

    Messages:
    7,350
    Location:
    Yakima WA
    Agreed that making the drain configured correctly may be costly, that's the only option you have. Please realize that changing from Toto toilets to any other brand will not fix the problem. This might be a time that a plumber would offer the most cost effective solution in the long run. He would not only do it right, but probably would have it completed in the time it would take you to figure out how to DIY.
  5. Terry

    Terry Administrator Staff Member

    Messages:
    15,011
    Location:
    Bothell, Washington
    Any toilet with a 3" or larger flush valve will push some water from the opposing toilet bowl.
    Using a slower flushing 2" flush valve will mitigate the issue.

    That being said, I do plenty of installs on back to back toilets, and yes you can lose some water in the opposing bowl. It's not that big a deal.
    However, my new installations are being piped with that in mind. Rough In plumbers, are you reading this?

    [​IMG]

    A double wye fitting on the left is okay
    A double fixture fitting is marginal, it will still lose water in the bowls.
    A double Santee on the right doesn't not work well at all.
    Last edited: Apr 9, 2014
  6. BruceG

    BruceG New Member

    Messages:
    3
    Location:
    San Jose CA
    Terry - thanks for the input. So where were you when they built this house in 1973? :)

    Would you have a recommendation for the "best" 2" toilet to look at? By the way, this is part of a remodel, not a DIY job. If completely necessary we'd have the plumber make the changes, but he's told us that it's not simple (or cheap) and I have good confidence in him - he's experienced and has done a good job for us.

    Bruce
  7. jadnashua

    jadnashua Retired Defense Industry Engineer xxx

    Messages:
    22,023
    Location:
    New England
    There are several brands that use a 3" flapper because it allows a great amount of water to fall fast, and that is necessary to get a toilet to work well with a little amount of water. Pressure assisted toilets might get by with a smaller flapper, but then you have to deal with the noise, the splash, and the shorter life of the components. Plus, many power assisted toilets shread the paper and waste, and often leave little bits in the bowl. not my first choice! Your application might work okay, but is not optimum.
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