Korky anti-siphon 528 is a trusted brand of fill valve for your toilets. It protects your toilet against any kind of flapper leaks and overflow of the tank.
Sometimes you might go to use your toilet and find your Korky anti-siphon 528 hissing and making weird noises. But why is this happening?
The fill valves usually make this kind of hissing sound when the air inside of it cannot pass or if the fill valve has defected somehow. The hissing sounds from the fill valve get annoying sometimes so let’s just not sit back. We have to fix it!
You don’t always need a plumber to fix things. The task we are talking about can be done all by yourself. But before that, let’s have a look at some common reasons behind the hissing sound and their fixes.
Reasons Behind Hissing Korky Anti-Siphon 528
Knowing the reasons for a problem would help you find the best remedies. That is why we will first discuss the probable reason why you’re facing such an issue so you can fix your fill valves on your own.
- Leak In The Valve
One common reason behind the hissing problem is that there might be a leak in the valve.
The fill valve handles a significant amount of water pressure throughout the use of the toilet.
So, even a small leak inside the valve would cause a kind of noise or hissing like this.
The bigger the leak in the valve, the louder the noise gets. So, a large leak in the valve would make a noise like water following from your tap.
The leak may cause your toilet tank to overflow as the fill valve would not be able to maintain the water pressure level with a leak on it.
Eventually, water from your toilet tank will overflow. So, it is best for you to take immediate action for the leak, or else you will have to face bigger problems in the coming days.
- Air in the Water Line
Sometimes, the water line that supplies water to the toilet tank in your bathroom and also connects with the fill valve may have some air inside of it.
This air causes a noise or hissing sound from the fill valve the whole time your toilet tank is filling up. It would usually stop when the water of the tank is filled up entirely.
The hissing noise coming out of the valve should stop within a minute or two if it is caused by the air inside the water tank. If the sound doesn’t stop after a few minutes, then you should check the waterline and the pipe to see if there is any other problem with the valve or not.
Sometimes the water might overflow to the bowl pipe and this creates the hissing sound. It indicates that the valve could not turn off the water supply when it was supposed to.
- Defective Flapper
Flappers in your toilet play a very important role for the whole system to be running smoothly. Flappers prevent any water from escaping the bowl, allowing the fill valve to run properly and as required.
The unusual noise or hissing sound might be heard due to the malfunctioning of the flappers as well. The flappers might get defected due to being very old or any other foreign matter.
Due to this, the flapper loses its ability to hold the water in the bowl, and the water escapes from the bowl, causing the fill valve to function very slowly.
It works late from its usual schedule. This might also cause the toilet tank to overflow and create a mess inside your house.
- Misaligned Float Cup
The plastic float cup needs to drop straight down as water level rises. If the cup is tilted or misaligned, water will spray out the sides causing a hiss during refilling.
- Excess Sediment
Mineral deposits, sand and debris can partially clog the anti-siphon ports or float cup seat. This restricts proper valve closing and creates a pressure spray.
- High Water Pressure
Excessive water pressure above 80 PSI can also cause the valve to hiss from water blasting through small gaps during closure.
- Damaged Diaphragm
If the rubber diaphragm inside the 528 valve is torn, warped or deteriorated, it may leak causing audible hissing after the tank has refilled.
- Low Water Level
A low fill level in the tank can drop the float prematurely before the valve fully closes. The remaining gap sprays water creating a hissing sound.
- Bad Solenoid
In electronically controlled fill valves, a defective solenoid coil can fail to fully shut off resulting in leakage hissing.
How To Fix The Hissing Of Korky Anti-Siphon 528?
You can fix many of the trivial problems of your Korky anti-siphon on your own, but some may need the assistance of an expert. So, you need to know which problems are fixable by calling the plumbers and which are not.
Now let us dive in to see how many possible fixes you can have for the hissing problems you are facing with your Korky anti-siphon 528 fill valve.
- Fixing The Leaks
Leaks can be of different kinds. Leaks can occur due to loose screws of the valve. It also can be the case that the pipe itself has a punctured leak.
So, if it’s a leak due to loose screws, you just need to tighten it. At first, turn off your main supply. After that, open the valve and clean it properly using cleaners. Then place back the valve and remember to tighten the screw as much as you can.
This problem of leakage can cause many unwanted situations. So, it is better to address this problem quickly.
If you are doing the replacement of the valve, then we would suggest you seek help from some experts. You can call the nearest plumber to fix it. Replacing the valve is a sensitive task.
So, expert help is recommended if you are not experienced enough.
- Fixing the Air in the Water Lines
Sometimes air gets into the waterline and makes a hissing sound, which is very annoying. To get rid of that, you must open your waterline and attach it again, which would let the air out of the pipes. Then the annoying hissing sound would also go away.
To do so, at first turn off the water supply of the entire house. If you have a separate waterline just for your toilet, you just need to turn off that one.
When the water supply is turned off, carefully open the screws to your waterline connecting with the fill valve. Clean the pipe with cleaning liquids if there is any debris left in it. After you are done cleaning, carefully attach it back.
If you see any defect inside the pipe, then you might need to fix it. Sometimes the pipe may be broken. So, in that case, you should change the entire pipe of the waterline.
While attaching the pipe again, be very careful to tighten the screws properly, or else the air will again enter the pipes and create hissing noises. If you are not confident enough, then ask for expert helps to fix your problem.
Korky has its own helpline as well. You can also contact them for any kind of assistance.
- Fixing the Flappers
Another common problem is the flappers not working properly. Flappers may have different kinds of problems. Sometimes they might get loose and sometimes they might get broken.
A loose flapper can be fixed within minutes by tightening, but a broken or old one needs replacement.
For fixing the flapper, you again need to turn off the water supply. Remember that for any kind of fixes you do to your toilet, you must turn off the water supply first, or else your house will be flooded with the toilet tank water, which is disgusting to deal with.
Now coming back to the flappers, reach down to the flapper chain and carefully open it to detach it from the system. An old and broken one must be replaced.
It is best to call a plumber to do this job as it is a very sensitive part of your toilet. One wrong step would ruin your entire toilet system.
Unless you are an expert on these things yourself, we would suggest you call one. And lastly, if you don’t have any idea how a Korky anti-shipon valve works, watch this video.
How to Clean the Korky 528 Anti-Siphon
If you hear sporadic hissing that continues after the tank has refilled, sediment buildup is likely preventing complete valve closure. To clean the 528:
1. Shut Off Water
Turn off water supply and flush out tank as before.
2. Remove 528 Cap
Unscrew the cap on top of the 528 device using adjustable pliers. Pull cap and internal parts out.
3. Rinse Components
Thoroughly rinse cap, diverter, seal disk and rubber diaphragm under hot water. Use tweezers to clear any debris clogging passageways.
4. Descale
For heavy mineral buildup, soak parts in white vinegar for 30 minutes. Then scrub with an old toothbrush and rinse.
5. Reassemble
Carefully replace parts in proper sequence in the 528 housing. Hand tighten the cap firmly.
6. Test Operation
Turn water back on and allow tank to refill, checking for any further hissing noises.
Removing built-up sediment debris from the anti-siphon ports and seat should stop intermittent hissing after refilling is complete.
How to Fix a Leaking Korky 528 Diaphragm
If cleaning the anti-siphon doesn’t solve persistent hissing after the tank has refilled, the rubber diaphragm inside may be damaged and leaking. To replace:
1. Drain Tank
Shut off water and empty tank completely using a sponge or cup.
2. Remove 528 Cap
Unscrew the cap counter-clockwise using pliers and remove internal components.
3. Extract Diaphragm
Pull out the rubber diaphragm, inspecting for cracks, tears or deformation.
4. Install New Diaphragm
Press a new diaphragm firmly into the valve housing, with the molded ring seated evenly.
5. Replace Parts
Reinstall remaining parts in proper sequence and hand tighten cap.
6. Turn On Water
Refill tank and test for leaks, adjusting water level if needed. This should stop any post-refill hissing.
Swapping in a new diaphragm typically fixes a leaky Korky 528 causing it to hiss after the tank has refilled. This inexpensive part preserves the valve function.
Frequently Asked Questions (FAQ)
Common reasons include misaligned float cup, buildup of sediment, damaged diaphragm, high water pressure, low tank level, and defective solenoid on electronic valves.
Gently bend the float arm so the cup aligns perfectly above the valve opening. Set tank water level 1 inch below overflow tube. Refill and test operation.
Remove cap and internal parts. Rinse thoroughly under hot water. For mineral buildup, soak in vinegar, scrub with toothbrush, then rinse. Reassemble and test operation.
Check fill valve alignment, clean internal parts, replace diaphragm if leaking, set proper water level, and consider water pressure reduction. Replace fill valve if worn out or badly mineral-clogged.
Final Words
Korky anti-siphon 528 is a great model to use as your toilet fill valve until it starts making weird noises. Your Korky anti-siphon 528 would make hissing sounds only when something is not functioning properly.
So, make sure to check every possible place for a fix and don’t just wait for the sound to disappear on its own.
