Back40

I recently (2 months) replaced both fill and flush valves in 2 toilets with Fluidmaster products. A week ago I noticed both toilets fill valves are turning on even though the water level in the tank is at the full mark. (Note: the water level at the full mark is below the overflow tube.) The fill valve runs for about 10 seconds before turning off. I did a test where I slghtly lifted the flapper allowing water to leak slowly into the bowl and found I had to allow the water level in the tank to drop at least 1.5" before the fill valve turned on. Therefore, this does not seem to be a problem with leaking around the flapper but a fill valve problem. Any ideas of additional adjustments I need to check/make? Thanks!

joecaption

There's a plastic coller around the shaft where the unit mounts to the tank it needs to be adjusted.
http://www.fluidmaster.com/index.asp?bhcp=1

Back40

Are you referring to adjusting the height of the fill value unit vertically? I have it mounted so that the ring is at least 1 inch above the overflow pipe per the instructions.

Redwood

Did you dye test the toilet? Blue food coloring in the tank will probably reveal water from the tank going into the bowl.

Did you use the supplied clip for the bowl refill tube or, did you just shove it down the overflow tube?

Back40

Have not done the dye test yet but plan to. I did use the clip to attach the refill tube to the overflow pipe so no siphoning is taking place.

Back40

Dye (blue) test on both toilets resulted in light blue water in bowls, so I'll be replacing the flappers next. Question about flapper design/fit, should part of flapper that protrudes into the water outlet be the same approximate diameter as the outlet? Currently, the diameter of both flappers protrusions is about half the diameter of the water outlet. Thanks!

Redwood

Try using either a Korky #2001BP or, for a 1.6 GPF toilet a Korky #16BP flapper. The Fuidmaster Flappers Stink!

karsar

I have the same issue with a fluidmaster system. I went and got a fluidmaster flapper & replaced the old korky with it. Still the water keeps leaking into the bowl (I can visibly see the water getting down into the bowl).

After reading this thread i have bought a set which contains korky flapper & also a replacement flapper seat with the silicone sealant. i am going to replace the fluidmaster flapper with the korky one and see if that will do the job.

if it doesnt what are my next options?

Redwood

Is the bowl refill tube placed down inside the overflow tube or is it attached to the top of the tube using the clip supplied with the Fuidmaster 400A?

karsar

The refill tube is placed down inside the overflow tube. This is a universal-rundall system from 14 years ago.

i havent replaced the fluidmaster flapper with the korky one yet. Should i go ahead and try that (or) is there something else that we can try?

Should i try the dye test? I am positive it will turn out positive since i can clearly see the water leaking into the bowl. How can i identify the part that is actually leaking the water.