Two-piece Gwyneth tweaks

We bought the two-piece Gwyneth for the latest Toto technology but were disappointed at first with the fine particles left in the bowl after a flush. A closer look revealed that the water level in the tank was well below the specified 1/2 inch from the top of the overflow tube, and that there was quite a bit of slack in the chain from the flush handle to the flapper. My guess is that the head pressure was below spec, and the flapper was not being pulled completely open. A couple of quick adjustments and the flush is now as advertised. It seems the Gwyneth does do a great job at 1.28 gallons but needs a proper set-up to do so; reasonable for a high performance design.

I have two 2-piece Gwyneths, one in my home and one in the showroom bathroom. I can confirm about needing to adjust the water height in the tank to the appropriate level. I have had one or two instances where particles remains, but i consider those flukes, rather than a problem.

As far as a chain adjustment, does this really improve the flush to the stated 1.28 gpf or simply increase the amount of water over the 1.28 gpf?