**Before you say “get a new flapper!” I want you to know I DID THAT. **In fact, I replaced the whole insides - fill valve, flapper, all of it. It’s cheap and easy and not something that can be easily messed up.
My toilet has been filling itself, ever so slightly, EVER so randomly, for a month or so. Since I work from home in my teeny little house, I’m lucky enough to be close to the toilet most hours of most days so I hear it. MAYBE once a day, or none some days and more than once some other days.
I checked for external leaks, there are none. As I said I replaced the flapper and the fill valve and they’re good.
Any clue what I should do next?
The toilet itself is probably about 10 years old. It’s the cheapest one they sell at Home Depot but it gets the job done.
It sounds like the flapper isn’t matching up to drain hole cleanly. As it is a new flapper, did you inspect the drain hole? It might be as simple as cleaning it with a scrubby pad.
Man I hate when this stuff happens. I have a toilet in the house which when the flapper etc goes it leaks very very slowly. You have to practically have your ear in there to detect it but when enough has leaked out the water comes on to fill for about 5-8 seconds. I usually have to do at least one of each of the suggestions above in order to get it sorted.
It might be that you’re noticing this when your water pressure changes. I think some toilet fill valves take more force to close when the water pressure is higher. In my house, with a well pump, I might flush the toilet and it fills and stops, and whatever cycle of the well pump we are in continues as we use water here and there. Then the pressure gets low enough that the pump switches on and runs a while until the pressure gets much higher, twice as high possibly. Once it rises above approximately wherever it was back when I flushed, the equilibrium point for the float force and the valve force requirement shifts, and the toilet runs a little to raise the tank level and the float force.
I have a Toto toilet that was causing me a problem like this. I replaced the parts and still had a problem. But I was using a third-party thing and not genuine parts. I did this, because that’s what was available from Home Depot and Toto endorsed them.
I talked to Toto customer service on the phone and found out I could order the genuine part which has a completely different design than the third-party. I put it in, and no more leaks! So if possible, try a different design for the internals of the toilet.
Put a few drops of food coloring in the tank and shut the water off. Check back on it a few hours later. If the dyed water is in the bowl you have a leak from the tank to the bowl, in all likelihood, it’s the flapper. It is possible to have it not installed exactly right (it has to sit on the drain just right and there should be a little bit of slack in the chain). If the dyed water hasn’t made it into the bowl, it’s the fill valve. Either it’s bad or needs to be adjusted.
That’s really it. Either the valve is calling for water when it shouldn’t be or water is exiting the tank. Throw some dye in there and you should be able to narrow it down pretty quickly, or at least over the course of a day or two.
I was going to suggest the food coloring trick, but Joey beat me to it. So I’ll just second his suggestion. It’s an easy way to determine whether the flapper is leaking.
But, for real, just a few drops. Just enough to notice it. I don’t know that it’ll stain the porcelain, but even a few drops will take multiple flushes to clear it all out of the bowl.
Sometimes gunk (algae? mineral deposits?) can build up on the flapper valve and the edges of the drain pipe, and keep it from sealing properly. Try cleaning them thoroughly.
The flapper rests on top of a rubber gasket / interface between the tank and the bowl. Make sure you replace that as well. It may seem fine, but the slightest imperfection could cause exactly what you are describing, a slight slow leak. For months, I had the same issue. I kept replacing the flapper and bowl and adjusting the chain, but I finally replaced the rubber gasket and solved the problem.
Something else to keep in mind. Before you spend too much money trying to fix this, remember, you’re not going to recover your investment for a long, long time. In my area, a gallon of water, with all the fees included, costs 0.5¢ (half a cent). Based on that, if you lost a half a gallon of water every day for a year, it would cost $1.00. However long it takes to lose 1000 gallons is the payback period of a $5.00 part.
Don’t get me wrong, it would bug me and I’d fix it too. I’m just pointing out that this isn’t costing you hundreds, or even tens of dollars a year.
Also, if you’re in an area short on water, that’s different too. Years ago I pointed something similar out to a board member that was leaning towards a more expensive dishwasher because it used less water (like a fraction of a gallon less then the other one). She mentioned that getting the model that used a bit less water wasn’t about the money, it was about living in CA or AZ and not wanting to waste any water she didn’t have to.
Anyway, before you throw any more money at it, at least do a dye test (with the water shut off) to isolate the problem.
JoeyP - do the dye test. If there is blue in the water your flapper is screwed.
Edwardcoast - If your flapper is screwed, replace it with the original part not the “compatible” Home Depot or Lowes part.
I replaced the flapper on my Kohler with the compatible HD one. It still leaked. I called Kohler and they suggested trying an original part and that worked. For my model, the original was maybe +10% more than the generic replacement.
Depending on your toilet style, another check you do is to shut the water supply off as soon as the toilet flushes (so it can’t fill back up). Then monitor it. If the flushing/filling stops then the defect is between the flapper and below the high water level. Kohler suggested this - they have a type of cylinder that runs up the middle of the toilet that can crack somehow.
Thanks all! Good info. I’ve been busy since I posted but will start with the dye ASAP and see where that gets me. Likely culprits are either the gasket being faulty or dirty. Hope I didn’t throw away a gasket that came with my replacement kit! Pretty sure it didn’t have one.
I’ve been using bromine tablets (meant for hot tubs), at least partially, because they’re supposed to be less detrimental to the tank innards. It’s also one of those systems where the water that goes directly to the tank gets rerouted through a tablet holder (actually meant for chlorine tablets), then down the overflow tube. That’s system, in and of itself, exists specifically to keep the chlorine out of the tank.