I’ve got a Toto toilet whose fill valve wouldn’t shut off. I thought the excess water was going down the overflow tube but due to recent developments, I think I may be misremembering. I just figured it needed a new fill valve and didn’t do a lot of troubleshooting.
Anyway I swapped out the fill valve and when I flush the toilet, it fills up to the cutoff, turns off, then the water starts instantly draining fairly rapidly. You can see the water line go down by the second.
There is no water going into the bowl so it’s not the flapper. Not only did I look very closely, but the amount that was draining would surely have been visible. There is no leaking water anywhere on the floor. The leaking sound sounds like a weak urine stream into water, so the water seems to be dropping from some height into water below.
The sound is in the lower back part of my toilet. I see no visible cracks in the toilet tank, especially one that could produce that degree of flow, but wouldn’t that dump the water into the bowl or on the floor anyway? Anyone have any idea what could possibly cause this? Thanks!
Try putting some colouring into the water Coffee? Not food colouring, it’s hard to clean I hear. And preferably not something yellow…
That will tell you if there’s some other bypass to the bowl. I presume you can tell whether there’s water going into the floor or wall by now, if the volume is that great…
BTW, what does this do to your water bill? I assume once the tank drops enough, the water flows again.
The toilets I’ve seen, there’s an overflow pipe above the flap valve (If the tank gets too full, it goes down this pipe into the bowl instead of overfilling all over the place). I wonder if that pipe is leaking at the bottom around its base or has a hole or something. Was it part of replacing the flapper or is it still the original? Some replacement parts I’ve seen include this whole setup - overflow pipe, float, flap valve…
Bold assertion, given you haven’t said how you determined this.
After the tank fills, put some type of safe colorant (food color, etc) into the tank water and see if it doesn’t end up in the bowl.
Your only real alternative would be the floor by leaking out of the tank and color would help make that obvious (unless you pick a color that wouldn’t be visible in contrast to the floor).
I thought of doing the color test but thought it unnecessary. I’m aware that it’s very difficult to see small leaks but this is much too fast a leak and there’s no movement in the slightest. More importantly, I can hear it leaking in the lower back of the toilet behind the bowl. The tank empties in less than a minute. That kind of water going into the bowl would be clearly visible.
The tank can have three sets of holes below the waterline through which water can leak:
Water inlet. Water can escape around the valve body seal, in which case it would run out onto the floor or, if the geometry is right, along the inlet water line. (Which may be onto the floor, eventually, but without a cutoff valve I could imagine the water capillarying into the wall.)
Outlet to the bowl. Water could leak past the flap or flush valve into the bowl, or around the outlet body onto the bowl pedestal. From there, the only place to go would be the floor.
Bolt holes which secure the tank to the bowl pedestal. Like a leak around the outlet tube, those would seem to inevitably end up with water on the floor (or soaking into the subfloor, if it can get past the flooring without puddling).
Ok so I decided to run a blue dye test. Maybe this toilet works in a different way because rather than seeing blue dye run down the sides of the bowl like I see in other toilets. Just a little blue water showed itself coming out of the flushing hole in the bowl, but most of it must have been going directly down the drain making that sound in the lower back. Now I’m confused how this thing is designed.
I pressed hard on the firm white plastic ring that the flush valve sits into and the leak stopped (at least until I pressed all around it to try and seat it better and it started again).
I’ve changed the flapper valve before but never the seat for it. I couldn’t see well but it looks like the overflow tube might have been attached to it. I’m not sure how the valve seat is attached to the bottom of the tank. Does anyone know if this is an easy fix or am I gonna need a plumber? Thanks for all your help.
You need to remove the tank from the bowl.
2 brass bolts and nuts hold it on.
Then, you replace all the defective parts, get new gaskets, and maybe new fasteners, and put it back together.
I once hadf a toilet that did this and the issue was not the flapper but the opening where it was supposed to seal when it was closed. there was a buildup of lime or something on that ring that kept the (brand -new) flapper from sealing
I would assume (!?) buildup on the flapper valve seat would have been obvious when the valve was replaced. However, it may be chipped or cracked or the buildup may not be a different colour. Try wiping and scrubbing the valve seat.
This is a modern low-flow toilet where the major part of the downflow from the tank is jetted out of that hole to encourage a vigorous flush actuon down the trap with a minimum of water building up in the bowl. That’s why the leak goes preferentially out the jet port – the flow out of the tank goes out that first and backs up to drain down the sides of the bowl after that outlet is completely saturated.
That’s exactly what happened to me. The tube had a crack around the bottom and the water just kept trickling through there. I replaced enough flapper valves to handle the ballast tanks on a submarine to no avail. Finally called a plumber who tracked it down.
And BTW, that overflow tube an only be removed from the below the tank, not from inside it. . .
And those brass bolts are likely corroded and will crumble as soon as a pliers touches the nut. My plumber had to shove a Swaz-All between the tank and the bowl, prefacing it with, “I can’t give you a a guarantee this won’t crack the porcelain.” Fortunately, it didn’t and he got everything put back together sucessfully.
This is actually a one piece toilet. It appears there’s two screws when you lift the flapper but there’s nothing online from a quick search that shows how to replace it. In fact i have the part number and still can’t find it. Now I’m not sure if the problem isn’t as simple as a bad flapper because when I pressed that hard enough the leak stopped too. Of course I don’t know if that was because I was also putting pressure on the valve seat. I suppose flapper is obvious first thing to try. Thanks.
Flappers can get brittle with age. Also, as mentioned above, the seat can get a build-up of calcium and other crud on it. Maybe hitting it with some scotch-brite would fix it. Or, that and replacing the flapper.
I have 4 Toto toilets I have to take care of, and I replace the fill valve and flapper in each them every 5 years or so. I’ve had slow leaks, and that’s always been the flapper. Sometimes the valve goes bad. It’s about a 10 minute job to replace everything for me now.
The flapper on mine doesn’t screw down. It clips to some pegs on the flush valve pipe. Note which ring of the chain is connected to the handle before removing the old flapper.
If the flapper is good and that hasn’t fixed it, I might try draining the tank, pulling the flapper, and then spraying the flapper seat with some Lime Away or CLR to dissolve any calcium buildup. Let it sit there for maybe an hour, and reapply every 15-20 minutes.
I have an old Mansfield toilet from the 1980s that doesn’t use a flapper but a rigid plastic plunger, the whole of which is lifted up by a rod connected to the flush lever rather than a chain. It seals against a small rubber ring, and if that ring isn’t PERFECTLY seated in its flange, it’ll leak.
Agreeing with this. It’s been revealed by the dye test. Flappers are the most common cause of these leaks. Often so slow they aren’t noticed and often called ‘silent leaks’. The leaks accumulate over time, and usually begin to leak more over time. Worse, the problem, or at least the degree of leakage can be intermittent.