Toilet valve water hammer problem

Sep 18, 2007 3 Replies

I've had a fluid master type toilet valve for 4-5 years with no problems until recently when it would shut off and the pipes would rattle from the water hammer effect. (This is the type where the float rides up and down on a shaft, as opposed to the ball float on an arm.) So I installed a new one and it worked fine for only about 1 month, and then it too started rattling the pipes when it shut off. I then installed another, and again, after 1 month, it did the same. Now....


  1. Our water has not changed, and it soft county supplied and we have no problems with deposit buildup.


  1. The other toilets (all single story home) have the same valves and work fine.

  2. No other water hammer problems in the home ever.

I've turned the toilet shut off valve halfway off to slow the water flow and that has solved the problem. But I'm curious if anyone knows why this might be happening?



Thanks



You might have a pipe losse in the wall or have you added any pipe.

I should not have used the word "rattle". Sorry. I have not added any pipes and they are not loose. The water hammer is a very solid thud.

It could be that the pivot where the float attaches to the valve head is a little corroded and isn't moving freely. That might cause it to 'jerk' to the closed position once the water level gets high enough to exert enough pressure to overcome the resistance caused by the corrosion. Try a little WD40 on the parts that should be moving freely to see if they loosen up some.

Otherwise the valve may be going and will need replacing.

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