Putting a pressure assist in an older toilet.

[Terry]

I got asked today by someone from Arizona about putting a pressure assist in an old Kohler toilet. He wanted to switch out a gravity tank with a pressure assist tank. He was telling me that the pressurized air would produce a great amount of water. A huge amount in fact.
I tried to tell him that they only produce 1.6 gallons at the most, and that the bowl is a different configeration that is designed for the push the pressure has. It's not for a siphon bowl. They are not gor gravity bowls.

Any bowl before 1992 requires at least 3.5 gallons, and pre 1985 5.0 gallons or more. Putting a pressure assist that only outputs 1.6 gallons is a waste of time and money. If you want a pressure assist toilet, you buy it as a set. A matched bowl designed for it, and the tank. Kohler makes a nice pressure assist toilet with a Flushmate.

K-3493 Kohler Highline with pressure assist. Not to be mistaken for their gravity Highline with a different bowl and tank.

 

[Flapper]

Any bowl before 1992 requires at least 3.5 gallons, and pre 1985 5.0 gallons or more. Putting a pressure assist that only outputs 1.6 gallons is a waste of time and money.

But the pressure assist would provide more boom so the results would be different. Would be fun to experiment.

I think a better idea would be to make a high tank toilet. That would be a fun project.

 

[Sponsor]

 

[Terry]

But the pressure assist would provide more boom so the results would be different. Would be fun to experiment.

I think a better idea would be to make a high tank toilet. That would be a fun project.

Using 1.6 gallons on a five gallon bowl does nothing.
And a Flushmate pushes water through, the other bowls work on siphon. It's horrible. All over the Flushmate site they warn against trying.
The bowl has to match the power curve of the tank.

 

[Jadnashua]

An older toilet probably does not have a siphon jet and the washdown holes in combination, would probably not work at all. Most of those old bowls required the thing to nearly fill up to generate enough head pressure to start the siphoning and empty...there's no way to increase the volume of a pressure assisted device, so it would spray out making a mess, and then, not have enough volume in the bowl to start the actual flushing.