Toilet hissing and tank emptying when water shut off

[Joe Kenney]

Hi all, hope you can help -- have never had such a persistent toilet tank issue. It started hissing some months ago.

First I replaced the flapper, with the basic Korky Universal. The tank still kept hissing. I put vaseline on the bottom of the flapper and used an old toothbrush to clean off the hole that the flapper covers. Still kept hissing!

Then I replaced the old Korky Quietfill Valve with a new one. Still kept hissing! If you shut the water off overnight, the water actually drains from the tank.

Then I went out and got a new Korky flapper -- this one is the "Standard" flapper, which is slightly more expensive than the Universal one. This seemed to fix the issue...for a few days. Now the tank is hissing again, and the tank will still empty overnight if you turn it off. Even if you shut the water off and the tank is mostly full, you can hear the occasional dripping sound.

I've reached the limits of my skillset with this issue. Could it be as simple as the new Quietfill valve being bad? I've checked that the valve is on the correct level -- ie lined up with the stem, or whatever it's called. I followed Korky's setup video during install. Or is there something else I can do to finally fix this hissing/tank emptying?

Thanks!

 

[bud16415]

The only way for water to leave the tank is thru the flapper if the float is shutting the water off correctly at the right fill height. So if you are shutting the water off and in the morning the tank is empty the flapper is not making a perfect seal.



The hissing you hear is the level dropping and then the flow valve opening replenishing the water that leaked past the flapper.



I have had great luck with the Fluidmaster brand fillers and I really like them because the snap ring height adjuster built into the stand tube is also a quick method of replacing the unit without having to break the seal at the bottom of the bowl. I can change a Fluidmaster in less than one minute. As to flappers I have used the Korky brand and they have worked ok. Getting the spacing correct so they fill the hole sometimes can cause a slow leak.



I will say some toilets just don’t want to seal well. My mother had a toilet my dad put in back in the 60s and he was nonstop fiddling with it half his life until took over the job. Finally I had enough and went and bought a new cheap toilet to replace this top of the line low tank expensive one and even though she didn’t care for the look it stayed sealed year after year.



Sounds like you have already tried all my tricks. Maybe others will chime in.

 

[Sparky617]

I wouldn't think that Vaseline would help, and may hurt the seal. I second FluidMasters, I've had good luck with those. Hissing is definitely the water running to refill the tank that is leaking out of the tank. The other thing to make sure is that you're not overfilling the tank. The water should stop about an inch below the overflow tube.

 

[Snoonyb]

The flapper seats into the flush valve at the bottom of the tank and these can become damaged, as swell as build calcium deposits.