Hello.

I recently installed a Fluidmaster 400C valve into my toilet. The toilet will periodically run or sound as if it is filling with water. I have tried adjusting the fill valve and the float cup but nothing seems to be working. Can anyone provide me with any insight as to how to stop the toilet from running?

Thank you in advance for the help.

Mark

Eller, it sounds like you may have some debri caught under the cap of the fluidmaster. Turn your water supply to the toilet off. Take the cap off and you will see a small round seal. Clean any trash or debri out of it and put it back together. This would be the first place to look for trouble since the Fluidmaster is fairly new.

The image is of a 400a but the cap is in the same location on a C.

Here's a link to detailed instructions on how to replace or work on the seal.

http://www.fluidmaster.com/pdf/242_instructions.pdf

Take some green easter egg food dye or any dye make the water in the tank green. DO NOT FLUSH! wait overnight if the water in the bowl is now the same color your flapper is not sealing properly and its causing the water to cycle on because its leaking into the bowl. I still find myself replacing the valve when I just need a new flapper.
And they all don't fit nice, you may need to buy a better one that the chiepie that came with
Let me know
Frank.. Never an expert!

I checked all the checks and the Valve is still leaking and the water running into the bowl.

However if I fill the tank and shut off the water it does not leak into the bowl.

I installed a new 400C and it does the same thing it continues to run after shut off, yet when you turn off the water supply no water leaks into the bowl.

This is the third valve I replaced and each time I have followed the trouble shooting steps with the same problem.

I have photo copies of the Display and barcode for the purchased part.

Are you sure you don't have the water level too high? Set the critical mark properly? The fact that the level doesn't drop with the water off suggests same. Never saw 3 bad 400 's.

Checked everything according to the instructions and the water level was lowered. If the water is turned off at the valve in the wall there is no leakage. The bowl does not show the green dye and the level does not change.

Turn on the valve I have water flow to bowl, level in tank does not change.

Can't figure that one.

Quote:

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Originally Posted by gmrophe

checked everything according to the instructions and the water level was lowered. If the water is turned off at the valve in the wall there is no leakage. the bowl does not show the green dye and the level does not change.

Turn on the valve i have water flow to bowl, level in tank does not change.

Can;t figure that one.

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Make sure the little black tube isn't pushed too far down the middle fill tube. It should not be more than 1" down the tube.

Quote:

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Originally Posted by ma0641

Make sure the little black tube isn't pushed too far down the middle fill tube. It should not be more than 1" down the tube.

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That is done also, right now I have stopped the continueous running water in the bowl by turning off the valve at the wall.

On my way to buy the old fashioned ball float valve.

Those three other ball cock's were all FluidMaster's? And you had the same problem with every one of them? Why didn't you choose the other type of ball cock? The one with the float ball. Back to you, Tom

Quote:

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Originally Posted by speedball1

Those three other ball cock's were all FluidMaster's? And you had the same problem with every one of them? Why didn't you choose the other type of ball cock? The one with the float ball. Back to you, Tom

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I had one in the garage and the other was installed while I was out of town, when my son tried to fix it.

I have chosen the other one. And it is now working fine.

I won't be buying fluid master again that is for sure;.

Glad you get to problem solve. And we thank you for the update. Good luck, Tom

Thanks, it was just simply returning to the basic old fashioned plumbing and getting away from the complicated stuff.

We have a problem with FluidMaster in our area. Somehow, it seems, the water swells the hole shut on the washer and stops the flow. We replace a lot of FluidMaster washers.

Thanks again for the update, Tom