My Toilet Troubles

[ts8586]

Hi, folks. Glad I found this forum. Seems like it is very helpful. Anyway, I have a toilet that gradually loses water in the tank. When that has happened in the past, I replaced the flapper and the problem was solved. However, that didn't do the trick this time. All the parts in the tank were replaced with Fluidmaster brand parts (fill valve, flapper, etc, etc). Everything was good for a few months. Now I'm getting the same problem again. Tried a few different flappers just to be sure, but no luck.

Here's the part that stumps me and tells me it's not the flapper. I flushed
the toilet, and let the water refill to the normal level in the tank. I turned the water off because I saw that there was constantly water running in the bowl (it was very light, but you could see it). When I turned the water off, the water stopped filling up in the bowl. This was about a day and a half ago, AND, the water is staying in the tank. When the water is on, the tank was refilling every 10 minutes.

Does anyone know or have any ideas what my next step would be? Thanks for reading my post!

[HayZee518]

It may be the seat of the flapper valve. This is a plastic piece that is molded in one piece from a mold. The plastic "sprues" that make up the mold may have not gotten fully trimmed off the seat so there is a little high spot on the seat that keeps the flapper from sealing completely. This will explain why the float has not fully closed after a fill cycle and keeps leaking into the fill tube.

[Java_Bob]

This was about a day and a half ago, AND, the water is staying in the tank. When the water is on, the tank was refilling every 10 minutes.

make sure the tibe coming from the fill valve, that goes to the overflow is NOT below the water line of the fill or a syphen can happen

[LazyPup]

The repeated cycling of the fill valve is indicating there is a leak in the tank, which in turn causes a reduction in the water level, even though that reduction may be so slight as to go unnoticed to the naked eye.

The fact that the cycling does not occur when the water supply valve is turned off is obvious, there is no water pressure to activate the fill valve, but that in no way indicates the leak is no longer present.

The repeated cycling of the fill valve is indicating there is a leak in the tank. Understanding that the tank is made of vitreous china which is impervious to water, it then stands that the leak must be occurring through one of the openings in the bottom of the tank, whether that is the flush valve or the mount bolts or the tank itself is cracked.

You can test for a leak very easily by adding ordinary "Food Coloring" to the water in the tank, then allow it to set a while and see if the color is showing up in the bowl. If so, you have a leak.

(While I have never seen them in the Home Supply centers, most hardware stores have little packet of 2 dye tablets that are made for this purpose. Generally the test tablets are not on display but if you ask a salesclerk they will nornally give you a couple free or perhaps charge a dime or so).

Without question the flapper is the most common cause of a tank to bowl leak but it may not be a defective flapper. As Hazee has already pointed out, when changing a flapper it is important to feel the top of the flush valve discharge port with your fingernail. Even a slight buildup of mineral scale, perhaps a tiny piece of rubber from a deterioated flapper or a mold sprue will prevent the flapper from sealing completely. (Keep in mind that it is the physical weight of the water above the flapper that holds it in place. Water weighs .434lb/ft vertical and the depth of the water in a tank when full is typically about 10" so the actual pressure holding the flapper closed is approximately 0.04psi.) If you find a rough surface on the flush valve discharge port you might have some success by lightly burnishing the surface with a very fine emery paper.

Now while changing a flapper might appear to be a simple no brainer exercise, such is not the case. Years ago all toilets discharged 5gal/flush and nearly all flapper were the same, but as the standards reduced to 3.5gpf then to the current 1.6gpf it became necessary to slightly re-design the flappers, as a result, flappers are now rated by gpf and it is important that the replacement flapper you get is the correct GPF for your toilet. (Fluidmaster now makes a universal flapper that has a rigid plastic mounting system and the rubber ball is indexed so you can actually turn the ball to dial in the correct GPF to match your toilet.)

There are typically two methods used to mount a flapper ball on the flush valve. The most common method is the little plastic mounting arms extending off the sides of the standpipe and the flapper arms have holes through the rubber that snap over the mount arms. When changing this type it is important that after you remove the old flapper you must check the mount arms to be sure their is no mineral scale or old rubber debris on the arms that might interfere with the motion of the new flapper.

Check the mount holes in your new flapper. If there is any excess mold sprue in the hole you must clean it out or get a different flapper as that excess rubber will interfere with the intended motion of the mount arms.

Make sure the new flapper mount arms are completely past the end stop on the standpipe arms so they are free to move.

Check the length of the pull chain carefully. If the chain is too long the excess chain can get sucked into the flush valve during the flush cycle and will prevent the flapper from properly closing. This also results in a sluggish lift on the flapper when the flush handle is depressed, which then often results in a sluggish flush. On the other hand, if the pull chain is too short it will continuously hold the flapper slightly above the flush valve seat, resulting in water seeping under the flapper and causing the type of problem you are having. Properly there should be approximately 2 links of slack in the chain when the flapper is down and the flush handle is in the at rest position.

The seond type of mount uses a molded rubber ring on the flapper which is slipped over the standpipe and slid down to the proper place. This type of mount can be a nightmare to properly position. (see attached illustration)

If these measures have not resolved the problem the leak may be occuring in one of two places. It is possible that their may be a slight crack in the standpipe tube or the point where that tube connects to the flushvalve body. If so, it will require replacing the flush valve assembly.

If a flush valve assembly has recenty been changed and you still have a leak you will need to remove the tank and tighten the flush valve mount nut a bit more. (I generally apply a light film of clear silicone sealer to the mating surfaces of the flush valve rubber gasket when installing a flush valve.)