My toilet (American Standard 4078) has been acting weird last month or so. Every 2 minutes or so, a little amount of water slips from the tank into the bowl and the tank makes the gushing/hissing sound for 2-3 seconds to top it off. Mind you, it's not that much water that it flushes by itself.. . can't be more than a quarter cup.

I have changed flappers twice but that hasn't helped. The linkage does have the necessary slack. My plumber replaced the entire flush assembly and that did not help either. He thinks the entire toilet might need to be replaced.

Before I do that, is there anything else you can suggest?

Thanks,
K

Since water is leaking from the tank to the bowl there is a leak somewhere.

If you have replaced the flapper twice and the plumber replace the flapper and over flow assembly that should pretty much eliminate a leaking flapper.

The tank may have a crack in it near the drain hole but that doesn't seem likely.

The water level in the tank should be set to about 1" below the top of the overflow pipe.

The little black refill tube from the fill valve to the overflow pipe should be attached to the top of the overflow pipe, not stuck down in it. This is what I think is most likely the problem.

I don't think it's the whole toilet, but probably the gasket the flapper sits on. Please verify that was changed also.

Since water is leaking from the tank to the bowl there is a leak somewhere.

If you have replaced the flapper twice and the plumber replace the flapper and over flow assembly that should pretty much eliminate a leaking flapper.

The tank may have a crack in it near the drain hole but that doesn't seem likely.

The water level in the tank should be set to about 1" below the top of the overflow pipe.

The little black refill tube from the fill valve to the overflow pipe should be attached to the top of the overflow pipe, not stuck down in it. This is what I think is most likely the problem.

Holy Mackerel! hkstroud, you nailed it! That was the problem. The refill tube was inserted all the way down. I pulled it up as you suggested and the leak has completely stopped. If you don't mind, can you please explain the physics behind this?

talaniman: Thanks for your reply as well.

Your plumber should have caught that immediately. Not an unusual problem.


When the float drops and the fill valves opens, water comes out the bottom of the shank to fill the tank and water comes out the refill tube to fill the bowl. When the float rises and the water flow stops, the water in the refill tube, at that moment in time, flows out and into the overflow pipe.

If the end of refill tube is in the overflow pipe below the water level of the tank, the water flowing out of the refill tube, when the fill valve stopped the flow, will siphon more water in from the tank. This continues until the water level in the tank drops to the level of the end of the refill tube. Of course, if the refill tube is very far down the overflow pipe the float will open the fill valve again and the process repeats itself..

Harold sorry it would not let me gave you green, excellent explanation, also see the images below,Thanks.

John

Thanks John. Pictures always help.

Thanks John and Harold for the explanation. Appreciate it.