Reaches suggestion is an easy thing to try. Is this a rental or used only by you?
I am replacing Toto Aquias that do not winter well in unheated buildings at -20 F, or else they have just been less than stellar performers. In spite of repeated flush and fill valves replacements (water will continuously leak into bowl) necessitating the water be shut off at the floor tap immediately after each flush.
-20 F? Does not winter well? With no heat, all the water lines must be blown out with compressed air. That alone will not guarantee completely dry line's especially the fill valves In the tank.
It happened to me one time, one toilet would auto fill about every five minutes. After a week's effort replacing everything, the mistake I made was the fill tube was inside the overflow tube below the maximum Fill Line. This caused a siphon effect. The real kicker was it was right there in the instruction. The fill tube should be on a clip to hold it above the water line.
Toto said I could use a universal fill valve to reduce the flush volume. 1) Any experience with doing that? 2) Can I adjust the fill valve that comes in this Drake to achieve a flush volume of 1 gpf and still get good flush performance?
There is a balancing act between the tank and bowl. The bowl may whole .8 gal or a little less. On the flush the bowl needs to fill over the hight of its trap way to create a siphon to empty the bowl. You can see how much water is needed. Using a quart bottle full of water slowly pour water into the bowl, it will start to drain a bit but once the level gets high enough the bowl level will drop when the siphon starts. This would be you absolute minimum by how much water you poured in.
Toto said I could use a universal fill valve to reduce the flush volume. 1) Any experience with doing that? 2) Can I adjust the fill valve that comes in this Drake to achieve a flush volume of 1 gpf and still get good flush performance?
Korky makes or made a universal flapper that you adjust on how soon the flapper closes. I found it made no difference. The simplest thing to try is adjust the fill valve to lower the hight of the tank water level but as I stated, there is a balance. The get a good flush is how fast the water drops from the tank. The latest no longer use a flapper but a cylinder like device that lifts up to allow rapid water volume to drop quickly.
Why I asked is this a rental or not. I grew up with three sisters, mom and dad and for a while one bathroom. Our home was at the lowest elevation of the subdivision. Most homes used cesspools, not septic tank and field. The problem was the water table was very high whereby the cesspool would not empty into the ground, therefore the tank, had to be pumped out once or twice a year. For there was a golden rule, no flushing for liquids only, only the second user could flush. It wasn't to about 1975-79 that sewers were installed.
