Toto AP and larger GPF in-wall tank - time sensitive question

[ToiletChallenged]

I am finally finalizing the rough-in on our space challenged powder room. A key question has come up about the Toto AP wall hung toilet we’ve planned for. I’ve been told by one of their tech support reps that it can be paired with an in-wall .8/1.6 gpf tank even though it is described as a .8/1.28 dual flush toilet. The advice was to NOT remove the flow restrictor as doing so will cause the water to go over the rim. Presumably the larger tank will simply flush water into the bowl a little longer?

Then, on a second call, a support tech said you should NOT pair the .8/1.6 gpf carrier with the Toto AP. He was very emphatic about it and said the other tech rep was simply wrong.

Does anyone have any experience or other knowledge about the pairing?

 

[Terry]

You can push the flush buttons in and drain the entire tank in the wall if that's what you want to do.
So that being the case, why would it matter if you push the 1.28 or the 1.6 when the bowl will take anything you throw at it?
I have not talked to TOTO support about this, but when I'm servicing them, part of working on them is flushing with enough volume to make sure that everything is working well.
And yes, they work very well with only 1.28 on the full flush.
I see on this spec a pressure loss ring. That does raise some questions for me.

• For use with WT172M In-Wall Tank System

 

[Sponsor]

 

[ToiletChallenged]

Thank you Terry. I’ve read quite a bit about the need to scrub brush wall hung toilets frequently due to the limited water surface at the bottom of the bowl. I was hoping a 1.6 flush would do a better job of addressing skid marks than the 1.28 would. Is that a valid assumption?

If I understand what you are saying, one can hold the button in longer on a 1.28 flush and get the same effect. Is that right? If that does offer a better cleaning result then the 1.6 would be a matter of convenience - i.e. not needing to hold the button in longer. But, if it’s got some downside to pairing it, I don’t want to go that route.

Thoughts?

 

[Terry]

Pick up the in-wall 1.28
I think that most of the time, you're just fine flushing with 1.28 anyway.

 

[Tuttles Revenge]

I did a warranty call for Toto on a wall hung toilet with flushing issues. The real issue was that the rim jets were holding water that would dribble down hours after use causing staining..

However in the course of diagnostics, I played around with the mechanism on the side of the flush tower that supposedly controls the volume of water from 9L,6L,4.5L per flush. I could observe a noticable difference between the lowest and the highest flush. I think we installed a 4.5L (1.28G) AP with the flush tower left at 6L (1.6g). The homeowner hasnt called to complain about any overflowing issues, so I assume it has worked.

Smudge applied for clarity in the photo.

 

[Tuttles Revenge]

And just in case you are using a Geberit in wall tank/carrier. They have a similar adjustment. It just comes with the following warnings for users in the US.

 

[ToiletChallenged]

And just in case you are using a Geberit in wall tank/carrier. They have a similar adjustment. It just comes with the following warnings for users in the US.

View attachment 88930

Thanks @Tuttles Revenge! It is a Geberit. Are you saying even a Geberit sold as a 1.28/0.8 can actually be set to 1.6 (6L)?

 

[Tuttles Revenge]

I believe that they can. I only have 1 flush tower that I got a Long time ago when their system was very new and they didn't have any spare parts. We broke a part off the tower so I ordered new parts... From Germany!! It took weeks to get. I'm sure they're much more available now. I made them send me 2 sets of towers since they were so scarce.