1- Assess the water flow pressure into the tank. If the water pressure is too high or too low, it can create noise in the water flow valve. In order to assess the water pressure of the water coming out of the fill valve, pull off the refill hose right where it connects to the fill valve. Be careful, as water will be flowing if this is done while the toilet is filling.
• If there is a strong stream of water coming out, then the water pressure may be too high. If this is the case, try turning the water valve at the base of the toilet partly down, reattach the hose, and try flushing again. The lowered pressure may eliminate the noise.
• If the water pressure into the toilet is very low, then you will need to increase it. This will require you to investigate the fill valve a little further
2- Clean out the fill valve. If the water pressure is too low, it may be restricted while it goes through the fill valve. In order to assess this, you will need to take the top of the fill valve off and clean it out. First, turn off the water to the toilet. Then, take the top of the fill valve. Look for debris that could be impacting the water pressure.
• To clean out the valve you will need a large cup that you can hold over the top of it. With the top of the valve off, place the cup over the top and turn the water back on for a few seconds. The water should shoot up into the cup, taking all debris and gunk that was in the valve with it. Then, turn the water off and replace the valve cap.
3- Replace the fill valve if necessary. If you have cleaned out your fill valve and it is still making a lot of noise when the toilet tank fills, then you may need to replace it. Turn the water to the toilet off and then drain the tank by flushing the toilet. Remove the existing fill valve and take it with you to your local home improvement or hardware store.
• By having the existing fill valve with you, you can be sure to get a replacement that will fit your toilet.
• Ask an employee at the store to help you if you are unsure how to find the right part.
• Take the replacement part home and follow the instructions it comes with to install it correctly.