Issue with Aquia flush

I had three Aquias installed about 4 or 5 months ago. Overall I'm very happy with them. However, they all suffer from the same issue, namely that more often than not, pushing the number 2 flush button only flushes the same amount as the other button. Occasionally it will flush the whole tank, but usually not. This happens whether I push with the button on the lid, or if I take the lid off and push the button directly inside the tank. The tank fills to the correct height, right at the fill line. And the low flow flush lowers the water level by 2 or 3 inches. All three toilets were installed by the same person.

I've been getting along by juts holding the button in until everything flushes, but I've reached the point where I'd like to improve the situation. Is there something simple to adjust which will fix this? Looking at the manual, I only see an adjustment for the low flow flush amount, not the high flush.

Thanks,
Jerry

Well...are you sure that there is no difference between the two? Remember that the difference is only going to be .7 gallon in total, or less than 3 quarts of water. It should be somewhat noticeable but it's not going to be an amazing difference. I don't believe that in either event it is supposed to drain the whole tank (unless you are talking about the wall-mount version).

I would call toto customer service 1-888-295-8134 and talk to them about it. It's the first time I have heard or seen this complaint, and it seems odd that it would happen on all three toilets. Let us know what you find out.

I guess the bigger question is, does it actually flush the stuff away when you flush? If it does, don't worry about it! Almost no current toilet drains the tank with a flush...they rely on the height of the water to help propel what water they do use. It also helps prevent or limit condensation since there's some room temperature water in there to temper the cold incoming replacement water, often, keeping the mix above the dew point.

The unflushed depth of the water in the tank is 7 1/4". Pushing either button lowers it by ~2 3/4". So no discernible difference. I suppose it's possible that the low flush is adjusted to the largest amount, if it can be as large as the large flush. But I haven't tried to measure the actual water amount yet. Ok, hold on...

I turned off the water, flushed, and then poured water into the tank to bring it back up to the fill line. 96oz almost exactly. 0.75 gallons. Which would put the total tank capacity at just about 2 gallons. So it's flushing less than it should be even on the low flush, and less than half of what the high flush should be.

For Jim's question, no, it's not quite flushing enough. I probably overstated when I said "drains the tank". I haven't measured the amount when that happens.

I can probably get the low flush up to 0.90 by adjusting the blue ring or raising the fill level, but it probably won't help the high flush much.

Normally I would tell you that you are leaving out the bowl-refill water, but as the Aquia is a washdown flush, I'm thinking that this is not a large amount. There is a refill hose and a percentage of the water coming into the fill valve is going to be diverted into that tube. The actual measurement, of course, is going to be the amount of water that rolls through the angle stop on the wall from the moment that you push the flush button until the moment the unit turns off.

On a Drake II/Vespin II/Ultramax II/Carlyle II, the refill percentage is 28%. On a 1.6gpf G-Max flush, the refill ratio is 40%. So...on a Drake II, you lose a gallon from the tank in the flush, and while that gallon is being refilled, .28 of a gallon goes into the bowl to refill it, leaving you with -- duh -- a 1.28gpf toilet. On a G-Max flush, the refill gallonage is x/1.6=.4 or .4*1.6=x so .64 gallon is used on refill and .96 gallon is drained from the tank in the flush.

I am only guessing on the Aquia, but it used to use the TSU09A.8R "Dual-Max" fill valve. I can't find the refill percentage on that valve anywhere, unfortunately...