A toilet hissing sound can be very annoying to both residents and neighbors sharing the walls of the toilet.
In addition, the toilet may be wasting a lot of water depending on where the hissing is coming from.
Let’s talk about how toilets make this hissing noise, and the quick, easy, and cheap DIY methods to stop this.
Damaged or Wrong Size of the Toilet Flush Chain
After every flush, the flapper located at the toilet tank base needs to be shut completely to store the next water cycle.
A chain is attached at one end on top of the flapper, and the other to the toilet handle’s extension arm.
Whenever the chain stops the flapper from closing or is too long that excess chain is stuck underneath the flapper, the toilet makes a hissing noise.
And when the chain is too short, the flapper will remain slightly raised and allow water to continuously pass from the tank. This also results in hissing sounds from the toilet.
Fixing a Toilet Flush Chain
Your toilet flush chain may have been sized incorrectly during its installation, or it may just be warped up and shortened.
If so, you can easily adjust the chain. Otherwise, you can replace the chain entirely if it is damaged. This replacement would cost around $2 to $3.
- Take out the lid of the toilet tank and place it aside.
- Use a flashlight to examine the chain to ensure it is not bunched or twisted up, or caught on any other component of the toilet tank.
- If twisted up, straighten the chain out while it is still in position.
- If this does not work, shut the water supply to the toilet and flush out the water in the tank.
- Reposition the toilet chain to the right length. It should be long enough to close the flapper and not twist or get stuck underneath the flapper.
- A rusted, mangled, or old chain is more likely to get twisted up than a new one. Replace your existing chain if it is damaged or old.
Dirty Flap Valve and Seal
The flap valve is a pivoted flapper at the toilet tank base that lifts as needed to allow water to flow into the bowl.
This flap valve can be red, blue, black, or gray, and it can be made from hard plastic, rubber, or soft silicone.
After being immersed in water over the years, the flap valve and its seal underneath can build up sediment, slime, mold, or other debris.
If any of them are dirty, it means they are both dirty since they are closely attached. This glop permits the flow of little water into the toilet bowl, causing a hissing sound.
Repairing a Dirty Flap Valve and Seal
- Locate the shutoff valve close to the floor and turn it clockwise to shut the water supply to the tank.
- Flush the toilet to empty the tank.
- Lift off the toilet lid and place is aside.
- Use a hand towel to carefully dry off the base of the tank.
- Use your hand to lift the flap valve at the tank base. Then use a flashlight to examine the base of the flapper and its silicone or rubber seal. Check that they do not have grime, slime, or sediment. If they do, clean them up.
- Scrub off the particles using a non-abrasive scrubbing pad.
- Then, dip a cloth in warm water and clean them.
- Reposition the flapper and turn the water back on to fill up the tank.
Deteriorated or Cracked Flap Valve and Seal
The flap valve at the toilet tank base opens to allow water flow into the toilet bowl or closes to refill the toilet tank. Since the flapper and seal are made from silicone or rubber, they’re prone to cracking or deteriorating over time.
When water leaks slowly through cracks in the toilet components or between a damaged seal and flapper, it causes a toilet hissing sound.
A damaged flap valve and seal cannot be repaired. Instead, they must be replaced. This replacement can be done using a universal 2-inch toilet valve repair kit, which costs around $10 to $1This kit normally comes with a toilet flapper, sealant, seal, and chain at times.
- Turn off the toilet water supply by turning the shutoff valve clockwise.
- Flush the toilet to remove water from the tank.
- Take out the tank lid and carefully place it aside.
- Use a hair dryer or towel to dry the base of the toilet tank.
- Take out the existing toilet flapper. Unclip the chain from it and leave the other end on the arm of the toilet handle. Detach the flapper ears from the pegs extending from the side of the valve tube.
- Take out the old seal.
- Install the replacement flapper by fixing its ears on the pegs of the valve tube.
- Attach the chain on the new flapper.
- While the tank is still empty, carry out a test flush to examine how the chain lifts the flapper. There should not be excessive slack on the chain to get it twisted up. However, a tight chain may not allow the flapper to seal completely. Adjust the chain as needed, either shorter or longer.
- Reposition the tank lid and turn on the water supply.