My toilet will not fill. It's as if the water line has completely shut down. Do I need to replace the fill valve?

ensure that the supply line is clear. shut angle stop valve off and remove line from bottom of tank place line into a pail and open angle stop valve, if clear water will flow quite readily. if not replace line. the fill valve is available at home depot. personally I would replace toilet with a quality American Standard. if your toilet is not a Glacier Bay good luck finding repair parts.

https://www.homedepot.com/p/Fluidmaster-Flapperless-Toilet-Fill-Valve-for-Glacier-Bay-Toilets-703AP4/202510398

If there is a continual leak in to the toilet bowl you will likely need to replace the flush valve or the toilet flapper.

As a first step try try cleaning the sealing surface of the flush valve to se if the flapper will seat and make a seal.

If this does not work and the flapper is visibly detioriated and breaking down shut off the water supply, remove the toilet flapper and visit your local plumbing supply store to purchase a suitable replacement. Install the new flapper, turn on water supply.

These illustrated instruictions may also assist:

http://www.danco.com/HowTo/How-To-Replace-a-Toilet-Flapper

Although less likely, if the sealing surface of the flush valve is damaged or detioriated proceed with replacement of the flush valve. Again turn off water supply and follow the instructions set out here:

http://www.danco.com/HowTo/How-To-Replace-a-Flush-Valve

If there is not a leak in to the toilet bowl and the water flow does not shut off completely, then water is flowing through the fill valve and the overflow pipe and you may need to adjust the float and float rod to allow clsoure of the fill valve. See here:

http://www.danco.com/HowTo/How-To-Replace-a-Float-and-Float-Rod

Is the flapper valve slow to return to the closed postion allowing water to flow through the flush valve? Make sure the toilet flapper is moving freely and is sealing properly against the flush valve. If there is no lengthy or continual water flow in to the toilet bowl then this is not the problem.

Is the water valve on the water fill line to the toilet tank fully open? This may seem silly but it could be this simple.

Check to make sure your fill valve is opening fully. If you have an older toilet there may be some deposits that need to be cleaned way to allow free movement.

If toilet does eventually fill to the desired level, there is no leakage, water valve on fill line is fully open and fill valve is opening fully then recommend you shut off water supply, drain toilet and disconnect water fill line from the water valuve and toilet tanke to make sure there is not a blockage. If the water line and connections are clear you may need to remove the fill pipe in the tank and check for blockage. If this is very old, conisdering the cost and effort, it may be simpler to replace at this time rather than trying to extend the life.

Hello...

To adjust the water level, you need to set the height at which the float shuts off the water valve. There are several types of floats. In older toilets, the float hangs at the end of an armature, along a metal or plastic rod. Where that arm connects to the water valve there is usually a screw. Adjusting that screw will change the level at which the water valve shuts off. If there is no screw or it is already at its maximum, you may be able to bend the metal arm, but you should remove it from the valve or risk damaging the fill valve.
In newer toilets the float is often a collar around the fill valve and rides up and down vertically. The float typically has a spring clip connecting it to a metal rod which connects to the valve shut off control. Squeeze the spring clip to slide the float up or down the metal rod.
Manufacturers have several variations on the fill valve mechanism, but they all include a method for adjusting the water level. Close inspection should make it clear how to adjust your particular fill valve.

I hope this helps!

there is likely a sediment build up either in the fill valve of the toilet or possibly in the supply line. You can try shutting off the water to the toilet, disconnecting the supply line from the tank and running the water into a bucket to see if the toilet is getting a water supply. If so, then you may need to replace the fill valve. For future reference:
Any time you install a new toilet or remove and reinstall a toilet, it is a good idea to flush the water lines (as described above) before replacing the fixture. This can help to remove sediment from the water lines and the Shut off valve and prevent the sediment from building up (and eventually clogging) the fill valve.

If you have a supply shut off to fixture shut it off and disconnect supply line from inlet to toilet . If your supply line to toilet is a flexible line then bend it so that you can direct water to small container. Slowly turn valve on to see what flow rate is at that point. If flow rate is not good then I would shut water off to house and replace valve. If flow rate to toliet is good I would reccomend you replace flush vallve. To do this shut off water supply to toilet. Disconnect supply nut to bottom of flush valve. There will be a retaining nut that holds flush valve in place in toilet tank. Remove flush valve after removing fill tube from flush valve to overflow tube. Replace with toto replacement valve or use Fluidmaster 400A. Instructions on box of 400A are easy to follow and if you have flex connector you won't need supply line washer. I would reccomend that before you install new valve that you put rubber gasket on shank of valve and slid it about halfway up the shaft. Make sure that inside of tank is dry and use a small bead of silicon caulking on top and bottom side of shaft gasket. slid gasket the rest of the way on valve shank,install in tank and put on retaing nut hand tight. Push down on top of valve and using channel lock pliers finish tightening nut securely.You may need to reach into tank and grasp valve body to stop it from turning. There are other things you can do if you have a working supply valve. Shut off valve and remove screws that hold top of valve in place and remove and clean surfaces. You can turn valve on slowly to help flush out any rust or mineral deposits. I hope this is of some help to you. Thanks

I would ckeck to see where water fill line is inside toilet tank and then adjust flush valve to try to get it to shut off at this point. Not knowing whether your toilet still has original flush valve it is hard to tell you how to fix it. If it has float mounted on rod to flush valve there is usually a set screw on the top of the flush valve in the center. Turn this screw clockwise to make valve shut off sooner. Try to set it so that water shuts off when it is at fill mark. If float is mounted on brass float rod you can support rod closest to flush valve with left hand and carefully bend rod down a little with your right. This will cause flush valve to shut off sooner. If the seat is worn to badly in flush valve you will need to replace it.

You don't have to replace, You just need to adjust the fill valve. If you have the ball **** type just tight the top phillips screw. If you have the newer type, close the water valve under the tank and Push down a plastic ring at the bottom of the filling valve, Push down the top of the valve, lift the plastic ring to it's place and open the water valve.

adjust the over flow

If you replace fill valve with a fluidmaster fill valve that should fix it right up.