How to Fix Slow Filling Toilet

If your toilet is filling slowly, there are a few potential causes. The most common is that your fill valve may have internal debris build-up. If you have a Korky toilet fill valve, you're in luck as our fill valves are 100% serviceable. 

If you have older technology, it may be time to upgrade. Also, ensure the water supply line, the hose connected to your toilet that runs to the wall or floor, is open all the way. If it is only partially open, the water may be restricted, causing your toilet to fill slowly.

Does this describe your toilet issue?

Outdated Technology

Older ballcock and fill valve models can become less efficient over time, causing reduced water flow and long refill cycles. Most of the time, sediment and debris can clog the fill valve, so it is essential to have a serviceable model. 

If you have a Korky model, you're in luck! All Korky fill valve models are serviceable and have a 5-year Warranty. If you do not, check out the 528MP, our most popular fill valve.

How to Service a Korky Fill Valve

  1. First, ensure that the water supply valve is turned completely open and that the supply line is free of kinks. If the supply line was kinked or if it was necessary to turn the water supply open, flush the toilet to observe the water flow. 

Kink in water supply line


  1. If this was not the problem, turn the water supply off.

Shut off water supply


  1. Pinch the refill tube and cover together to ensure the cap on the valve is completely tightened. After pinching, turn the water supply on and flush to see if the valve is working properly.

Pinch refill tube


  1. If this does not improve water flow, turn the water supply off and flush to empty the tank. Make sure to hold the valve firmly through all steps so it does not get turned out of the locked position.


  1. Next, remove the refill tube; you may need to twist it slightly.

Remove refill tube


  1. To remove the valve cover, place your thumb under the tab and lift it up. Please note, that the color of your Korky fill valve may vary by model number.

Remove fill valve cover


  1. Once the cover is off, remove the float by gently pinching the float arms towards each other (the float is the piece that has an X at the top).

Remove fill valve float


  1. Remove the cap assembly by grasping the cap firmly and turning it counter-clockwise on eighth turn (it looks like it has a set of railroad tracks at the top). While turning the cap assembly with your free hand, hold the body of the valve in place to prevent the valve from unlocking. We recommend rinsing under warm water to remove any trapped debris.

Remove fill valve cap


  1. Remove the supply tube from the valve by pulling straight and out of the valve (the piece that looks like a wagon wheel).

Remove supply tube


  1. Pull the white strainer from the bottom of the supply tube. Rinse the strainer under warm water to remove any sediment.

Remove strainer


  1. Insert the strainer back into the supply tube and insert the supply tube back into the valve body. Twist the cap assembly clockwise to lock it onto the fill valve.

Reassemble fill valve cap


  1. Once completed, reattach the float arms to the valve body. Pinch the float arms inward to clip them back into place. Tap the "X" on the float to make sure the float moves up and down freely inside of the black box, and is not scraping the sidewalls of the float chamber.

Tap fill valve float


  1. Reattach the fill valve cover onto the valve and connect the refill tube. Ensure the refill tube is clipped to the lip of the overflow tube. Never insert the refill tube down into the overflow tube; doing so may create a siphon and cause the valve to run continuously. 

Attach fill valve cover


  1. Make sure the valve is locked into place by turning it clockwise.

install fill valve


  1. Pinch the refill tube and the cover to make sure the cap is completely tightened. 

Pinch refill tube


  1. Turn the water supply on to test the water flow. 

Turn On Water Supply

How to clean and service a korky quietfill toilet fill valve