Fine-Tuning Water Closets
I could line up the ball, set the lift wires and bend the rod to adjust the float like a pro. Of course, that makes it sound like I come from a bygone era. Balls and lift wires have been replaced with flappers. Manufacturers now provide a set screw for adjusting the float.
We used to set the water level based on the performance of the bowl flushing. That used to be part of the real art to setting up a water closet. You wanted an optimum performance during the flush. Today, manufacturers punch the water level in the tank. This establishes the level for flushing the maximum 1.6 gallons of water as permitted by federal law.
What I have noticed, of late, is that many plumbers are forgetting how to fine-tune a water closet. Either that, or they never learned how to begin with. We have seen so many improvements in the quality of our fixtures that we assume that the manufacturers do it all.
I have spoken to countless plumbers who say when they install a water closet, they set it, connect the water, turn on the water and leave. Most of the time, the water is not on, hence, they cannot tune the water closet even if they are supposed to. They admit they never go back after the water is turned on to see how the water closet is performing. This sends shivers down my spine.
Unfortunately, I have been asked to investigate many of these water closets because they are reportedly failing. I would rather not have to check these installations, since they could easily be avoided. Everyone is quick to blame the low flow. Others curse out the manufacturer for developing a lousy water closet.
Incorrect Setting: Every time I investigate poor flushing water closets, I find the water closets were either never tuned or they were improperly tuned, making matters worse. The No. 1 cause for a poor flushing water closet is the incorrect setting of the water level. When the line is stamped in the tank, that is the level the water should be set at. If the water closet was never tuned after being installed, quite often, the water level will be higher in the tank.
I am amazed at how many young plumbers assume that the manufacturers set the water level in the factory. If you think about that, it is nearly impossible for the manufacturer to do so. A ballcock shuts off by a float. The float and float arm react to the supply pressure of the water system. The pressure supply for the water closet can be anywhere from 8 psi to 80 psi. How can manufacturers set this at the factory?
Some ballcocks have an attached float (without a float arm or rod). These ballcocks have much less tolerance between the allowable pressures. They are normally closer to the water level mark than the ballcocks with a float arm. However, they still need to be checked to make sure the water level is properly set.
The second biggest problem is the cutting of the buckets inside the water closet. Many of the manufacturers install buckets to reduce the amount of water being flushed, while maintaining the pressure head to flush the water closet. The cutting of the bucket normally occurs after the owner complains that the water closet doesn't flush worth a darn (probably because it was never tuned after installation).
Cutting the bucket is a dumb way to solve an easy problem. It voids the manufacturer's warranty on the water closet. It also results in the water closet violating the federal law requiring a maximum flush of 1.6 gallons. If caught, the penalties are high.
The cutting of the bucket comes from the thought process that more water is better for flushing. Thus, if you allow a greater quantity of water to go down the drain, it is guaranteed to improve the flushing performance. This mentality is screwed up! More water does not improve the flushing performance of 1.6-gpf water closets.
Apparently, we have allowed our thought process to turn to mush when the feds mandated 1.6-gpf water closets. Many of us grew up on 5-gallon water closets. In the 1970s, the water quantity for flushing was lowered to 3.5 gallons. Many manufacturers didn't do much to their water closets during this water reduction period. They just lowered the amount of water into 5-gallon flushing water closets.
Less Is More: When the reduction to 1.6 gallons was made, the manufacturers had to redesign their water closets. The design engineers will tell you that they designed the water closets for optimum performance with a flush of between 1.3 and 1.6 gallons of water. Less water and the flush stinks; more water and the flush is garbage.
The greatest performance is when the bowl flushes 1.6 gallons. If you question my intelligence on this one, just think of how a siphon action works. You attempt to get the maximum pulling force to evacuate the bowl. What is the best way to kill a siphon? Throw water into the middle of it. That water can reduce, or even stop, the siphon. Try it some time.
When the buckets are cut, or the water level is set too high, what are we doing to the water closet? We are killing the siphon. Too much water reduces the performance of the water closet.
If you remember the basics of tuning a water closet, the flapper should close off at about the same time that the siphon action in the bowl is the greatest. If the flapper is still open during the maximum siphon, you are killing the siphon action.
Every time I investigate massive failures of water closets, I end up demonstrating the difference the water level makes when setting up a water closet. A good field test is two lengths of toilet paper about 8 to 10 feet long, placed loosely in the bowl. With the water level set too high, the water closet is flushed. Quite often the paper will be removed, but the flushing performance is weak.
I then set the water level to the proper height. The same amount of paper is added to the bowl. This flush is stronger and easily removes all the water. The improved performance is very visible to the naked eye.
No, the 1.6-gpf water closets are not the same as the 5-gallon flushers. But they can operate very well when they are properly set up. Double flushing will become a rare, if not non-existent, condition when you set the water closets to flush exactly 1.6 gallons of water. No more, no less.