Kohler K-3493 Highline Pressure assist 1.4gpf - Weak flush

I manage a building with 176 pressure assist toilets. Building is 3 years old but I have been in conversation with Kohler for 3 years now trying to figure out why each toilet looses pressure resulting in weak flush or no flush. Toilet will flush for a few weeks and then will gradually lose its pressure. The bowl is labeled 1.4gpf and the Flushmate system installed is labeled 1.6 gpf (I don’t believe Flushmate manufactures a 1.4gpf). Over the course of the last three years and after spending lots of time and money trying to resolve the issue I think I am on the right track but can’t confirm and hope that this posting will help me collect more details from others having same problem.

I think.....
Kohler sells this model 1.4gpf toilet with 1.6gpf Flushmate tank installed and they put in a flow restrictor to reduce the 1.6 to 1.4. (Allowing themselves the ability to market a 1.4gpf toilet even though it appears to be the same tank as what is in their 1.6! Go figure!)
I have a limited understanding of how the pressure assist works, but I believe the pressure necessary to produce a good flush is built by the fill time, pressure and amount of water coming into the chamber??
So wouldn’t a flow restrictor limit the fill time, pressure and amount of water? And if those things are important than how can you expect it to work correctly?
And Why after I pull out the flow restrictor does my toilet now work?
Why is the flow restrictor NOT on the parts list?

All postings I have read about this issue seem to offer only one solution....and that is to pull out the flow restrictor. BUT WHY AM I THE CONSUMER BEING SOLD A TOILET THAT IS MARKETED AS "SAVING ME WATER", AND THE BEING TOLD TO PULL OUT THE WATER SAVING DEVICE TO ALLOW IT TO WORK PROPERLY!?
If I had a single family home with 2-4 toilets...then no big deal, but I have 176! We have spent a lot of money with Kohler to buy these 1.4gpf toilets.....it makes no sense that the only fix is to remove the water saver! Then why sell a 1.4 at all?? Now I have to pay a plumber to remove 176 flow restrictors?? Wouldn’t purchasing the 1.6 been a whole lot cheaper and easier?? Again...I have given Kohler over 3 years to help with this issue; any advice from this site is MUCH appreciated! Thank you!

As I understand it (not necessarily right!), when you push the flush lever, it starts a timer (mechanical) that keeps the pressurized water storage outlet opened for a specified time. If you put a restrictor, in the amount of time allowed, not as much water will come out, and it may be slowed down a little. My guess is that the timer isn't adjustable, so the only way to restrict the amount of water out is to put in that restrictor. I don't think it affects the fill time as the valve is reset on it being full, not time.

Now, whether that toilet actually would work well with 1.4gpf, your experience implies it doesn't. My (limited) personal experience with Kohler is that they do it their way and are severely infected with NIH (not invented here) - they like to do things their own way. There's a reason why most other companies use one of the tried and true methods to flush a toilet - they work, are easy to repair when necessary, and the parts aren't very expensive. Kohler often isn't any of those things. They often do look good, though. I prefer performance instead.

It is too bad you are stuck with these. My guess is when the building specs were made, the person selecting the brand went by the famous name rather than really finding out what works. Kohler is still living on their name and reputation earn in a much earlier time. Pressure assisted flushing is, in my not-so-humble opinion, a gimmick that is an attempt to make a poor design perform. There are some who think they are great, but most of us do not. I wish I could offer a solution to the problem, but other than buying 176 new Toto toilets, I don't see a practical answer.

Flushmate makes a 1.6 and a 1.1 pressure assist tank.
For Kohler, they also provide a 1.6 that is restricted down to 1.4



Kohler Highline 1.4 gpf pressure assist

When these are working, they work real well. Jimbo has a 1.6 that went 10 plus years before working on it.

When the 1.4 has problems, or really when any Flushmate has problems, the first step is to insure that there is good flow and pressure from the wall supply. Often we will disconnect the supply line and check the flow into a bucket.
If the restrictor on the 1.4 is reducing the flow too much, then historically, we remove them. Problem solved.
However, no longer do you get the water savings either. It reverts to 1.6 gallons per flush. I can see that it would be a large difference over 167 units.
Kohler also sells a 1.1 gallon Flushmate equipped tank. Those don't have the restrictor. I would think that Kohler would be wiser to push their 1.1 gallon model without the restrictors. I've been selling those if someone wants a pressure assist with Flushmate that meets the WaterSense standards.
The 1.1 GPF works great.

I refuse to sell the WDI EcoFlush dual-flush.

Other then the restrictor issue with the 1.4's, the Flushmate products have been pretty solid.

The Flushmate products do seem solid I agree...but seems to me that if the 1.6 flush works well and the 1.4 is having pressure issues wouldnt it be the restrictor?
isnt it the same equipment in both? just the restrictor added to the 1.4??

The only difference between the 1.6 and the 1.4 is the restrictor. Normal operation is high performance. Sometimes due to things in the water, the restrictor can get clogged. Removing that bumps it to 1.6 and best of all, takes the dirt and grime away that were blocking the flow.

Terry said:

The only difference between the 1.6 and the 1.4 is the restrictor.

Click to expand...

Can anyone help me figure out where the flow restrictor is on the K-3493 Flushmate unit? I've been searching the internet but cannot find an exploded view that identifies it. I would like to remove it as has been recommended above. Also, anything else I need to know about removal (other than where it is)? Thanks.

Bill Keegan said:

Can anyone help me figure out where the flow restrictor is on the K-3493 Flushmate unit? I've been searching the internet but cannot find an exploded view that identifies it. I would like to remove it as has been recommended above. Also, anything else I need to know about removal (other than where it is)? Thanks.

Click to expand...

I'm late answering this Bill. The restrictor on the 1.5 is on the water inlet where the water supply attaches. I bend a paper clip to a tight bend to make a hook, push it up past the grid and then pull it down and out.





This 1.6 was installed 11/2017 installed for Thanksgiving guests.