How to replace a toilet fill valve


A toilet is one of the most simple devices in a home. The toilet consists of a tank to hold water and a bowl below. The tank is filled with water via the fill valve and water exits the tank into the bowl via the flush valve (commonly referred to a flapper). There isn’t much to go wrong with this system but in the event that something does break replacing the faulty part is incredibly easy. No large plumber repair bill is needed for common toilet repair problems.

Today I’m going to talk about the fill valve. The two problems that you may have with a toilet fill valve are too much water or not enough water. If too much water is added to the tank the excess water will drain down into bowl via the overflow valve. If this happens the fill valve will run constantly and never shut off causing a lot of water to be replaced. The other problem, which is by far the less common of the two, is when the fill valve doesn’t allow the proper amount of water into the system.

Replacing a toilet fill valve is incredibly easy and anyone can do it. First turn off the water supply to the toilet. Hold the handle down on the toilet to flush as much of the water into the bowl below as possible.

HGMM toilet fill valve (1)

The fill valve is on the left side of the toilet where the water supply line connects to the toilet. Older style fill valves have a float ball on an arm that rises as the water rises and puts pressure on an internal shut off valve. These can easily be replaced with a more compact, universal toilet fill valve for just a few dollars.

HGMM toilet fill valve (2)

With the water turned off and the tank flushed put a towel on the floor below the fill valve. It’s nearly impossible to do this without spilling at least a tiny bit of water. Disconnect the supply line from the fill valve and use a pair of adjustable pliers to remove the retaining nut on the bottom of the fill valve threads.

HGMM toilet fill valve (3)

Just a little bit of water will come out of the fill valve body itself but when you remove the fill valve from the tank any remaining water in the tank that didn’t get flushed will leak out of the hole where the fill valve was. Use a small bucket or a large cup to catch as much of this water as possible when you remove the fill valve from the tank.

HGMM toilet fill valve (4)

I used a very common universal fill valve for the replacement. The float is actually attached to the shaft of the fill valve itself making it much more compact. It comes with the fill valve itself, a bowl refill hose, rubber gasket, retaining nut, and a clip for the bowl refill hose.

HGMM toilet fill valve (5)

Before installing the fill valve, slide the rubber gasket over the bottom of the fill valve as far as it will go. Place the fill valve into the tank and determine if the valve needs to be adjusted to be higher or lower. The bowl refill hose mounting location on the side of the fill valve should normally be about an inch higher than the overflow tube in the center of the tank. Adjust the height of the fill valve as needed.

HGMM toilet fill valve (6)

Once properly adjusted place the fill valve into the tank and secure it from below with the retaining nut. Tighten this slightly with a pair of adjustable pliers to compress the rubber gasket slightly. Then connect the supply line. Using pliers here is not normally necessary. You should be able to get this tight enough without any tools.

HGMM toilet fill valve (7)

Before turning on the water connect the bowl refill hose to the fill valve and place the other end down the overflow tube. If the overflow tube does not have anything to hold the hose in place use the included clip. Slowly turn the water off and check for any leaks on the connections outside the tank. If any are present tighten the appropriate fitting as needed. Finally, allow the tank to fill up completely. If the water level is too high or too low adjust the height of the float. The final height of the water in the tank should be about ½” lower than the top of the overflow tube.

HGMM toilet fill valve (8)

There really isn’t much to replacing a toilet fill valve. Anyone can do this and by doing it yourself you will end up saving a ton of money. Good luck!


  1. To avoid most water spill after removing of valve… I do this…Once I had turned off the water supply and flush water out of tank, I will use sponge to soak up the remaining water in bottom of bowl before removing the valve. Still may want a have towel below.


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