How to Replace a Toilet Tank Fill Valve

Unlike replacing the flush valve ("How to Replace a Toilet Tank Flush Valve"), fill valve replacement does not require that the tank be removed from the toilet bowl.

Difficulty: Moderate

Instructions

Things You'll Need:

• Adjustable Wrench
• Groove-joint Pliers
• Some old rags
• Bucket and sponge

1. 
   Shut-off valve

   Shut off the water supply using the shut-off valve located under the toilet tank, to the left as you face the toilet.
   
   Remove the tank lid and set it aside on a flat surface, so it does not get cracked or broken.

2. Flush the toilet, and hold the lever down to remove as much water from the tank as possible. When you release the flush lever, no water should come into the tank, as the water supply is shut off (if it does, the shut-off valve needs replaced or repaired).
   
   Remove any water remaining with the sponge.

3. 
   Water Supply Tube

   Disconnect the water supply tube (runs between the shut-off valve and the bottom of the toilet tank) from the fill valve stem.
   
   This should be a finger-tight connection, but may require the use of the wrench or the pliers. An old rag on the floor will catch any water draining from the tube.

4. 
   Toilet Fill Valve

   Disconnect the overflow tube from the fill valve (see diagram of parts). Now, while holding the old fill valve with one hand, remove the large nut that holds it to the tank (located outside the tank, below the fill valve).
   
   The fill valve may now be removed from the tank.

5. We reverse the order above to install the new fill valve.
   
   Insert the new fill valve with its gasket into the toilet tank, and through the hole.
   
   Attach the large nut, with its gasket, to the fill valve stem, under the tank body, and tighten finger tight; then tighten another half turn with the pliers.

6. At this point, I like to check this assembly for leaks. Since we haven't yet attached the water supply tube, do this by pouring some water into the tank with a tumbler or pitcher.

7. Lastly, attach the water supply tube to the new fill valve stem, and tighten finger tight; then tighten one half turn with the wrench or the pliers.
   
   Turn on the water using the water shut-off valve, and check for leaks. If none, you're done!

Tips & Warnings

• The water inside a toilet tank comes from the same source as your drinking water (although it looks pretty dirty sometimes), and poses no health hazard through touching it.
• When tightening nylon/plastic nuts, be gentle, as it's easy to strip the threads.