Wednesday, February 11, 2009
Nothing wrong, except it doesn't work.
The toilet in the upstairs hall bath has been making funny noises for a while. Went to fix it yesterday and naturally it was dead quiet. Downstairs toilet had been making noises earlier and I discovered that the flapper valve had some kind of mold or something growing on the sealing surface, causing it to leak. I figured the same thing was going on here. It's easy enough to fix, as long as the shut off valve is working properly.
The flapper valve just clips onto it's pivot points, so you just push up on the two arms, undo the hook and there you are. The mold, or algae or whatever it is comes off just by rubbing with your fingers. A little running water to wash away the debris and five minutes of rub-a-dub-dub, wipe off the sealing surface and put it back in, and you're good as new.
Or not. Now the water won't come on. Open up the top of the Fluidmaster valve, looks good, put it back. Water fills the tank, but now it won't shut off. Repeat this drill two or three times and we have no progress.
Go to home depot today and buy a new valve top. Put it on and everything works fine.
Okay, the toilet is working now, but I still have two problems. 1) What's wrong with the old valve? and 2) just how does this valve work in the first place? The float is connected to a lever. The other end of the lever is connected to a pin. The pin slides through hole in the center of the diaphragm. It does not actually push on the diaphragm, it just slides up and down.
On close examination, I can see that the top half of the pin has a smaller diameter than the bottom half. There is a collar that is on top of, and part of the diaphragm. There is a small hole in the side of the collar. So if the float pushes the lever up, the lever pushes the pin down, the smaller diameter of the pin reaches the hole in the side of the collar, and air is vented to the top of the diaphragm. So the valve would open, right?
You would need water pressure pressing down on the entire diaphragm to overcome the pressure of the water from the inlet pushing up on the smaller center section of the diaphragm. The area over the top of the diaphragm is not sealed, any water up there would just flow out the top of the valve. This does not make any sense and is extremely annoying.
A second round of searching the web produces this page, which does a pretty good job of explaining with illustrations, just how this mystery piece of equipment works. It isn't at all obvious.
Update March 1, 2009: Fix didn't take. If I'd left it alone it probably would have been fine for a while, but it had been making noises, so it was definitely headed for trouble. Replacing the fill valve fixed one problem, but evidently we didn't clean the flapper valve well enough because periodically the fill valve would open for few seconds and then shut off again. Went in and cleaned the rubber washer on the flapper valve again yesterday and found a very little bit of stuff still adhering to it. I think I got it this time because no more complaints about the toilet turning off and on.
Putting the rubber washer back on the flapper is kind of a trick. It is just a little too thick for the slot provided for it. Stretching the washer thins it out enough that it will slide in the slot, but by the time you've worked your way all around the outside, you are left with a bunch of extra washer all piled up in one spot. What seems to work better is to just push the washer down over the central projection. This leaves the upper edge of the inside of the hole in the washer facing up, it hasn't slid into the hole. Just pushing down of this visible edge is enough to get it to tuck into the slot. Work your way all the way around and you should be good to go.