Replacing a Toilet Fill Valve Guide of 2023

If you have a leaky toilet, chances are the fill valve is faulty. Toilet fill valves are designed to prevent water from running when the tank is empty. If your tank is full, the float ball does not float up and water flows out of the overflow tube.

When the tank gets low on water, the float ball rises and cuts off the supply of water to the bowl. It’s easy to replace a fill valve yourself in just a few minutes. You don’t even need many tools..just a screwdriver and wrench or pliers will do.

Toilet Fill Valve Replacement (Step-by-Step Guide)

Step 1 – Turn Water Off

The first thing you need to do is to turn off the water supply to the toilet at the shutoff valve under the sink. If there isn’t one, turn off the main water supply for your home. The shutoff valve is typically located on an exterior wall of your house, but it might be inside near where the supply line enters your home.

Step 2 – Remove Tank from Bowl

Next, unscrew each of the bolts holding together the tank and bowl with an adjustable wrench or pliers. There will be about four bolts in all – two at each side of the tank’s base flange and two more holding down the overflow tube inside of the tank itself. These bolts may be corroded, so be cautious when removing them.

Step 3 – Disconnect Water Supply Tube

Turn off the water supply to the toilet by turning off its shutoff valve. The valve is usually located on a pipe just outside of the wall or floor where it enters your home. If you can’t find this shutoff valve, check inside your basement for an access panel that covers plumbing for all of your bathrooms.

Step 4 – Remove Tank lid and Set Aside

open toilet tank against a blue wall

Remove the old valve by unscrewing it counterclockwise. If that doesn’t work, try loosening it with pliers to break its seal.

In some cases, you may have to remove other parts of the tank before you can access the fill valve. It’s important to take apart only as much as you need to in order to avoid unnecessary damage or leaks.

The old valve will probably be attached with a large nut or bolt on top of the tank, so you’ll need an adjustable wrench or socket wrench in order to get it loose. Once you’ve removed the old valve, set it aside so that you don’t accidentally drop it inside the tank while installing your new one.

Step 5 – Disconnect Fill Hose from Overflow Tube (Bottom of Bowl)

Remove any screws holding down the old fill valve so that you can pull up on it. If there are no screws holding down your old fill valve or mounting bracket, remove them by hand instead. Then disconnect your old fill hose from underneath your overflow tube inside your bowl by pulling on it hard enough so that it bends slightly outwards away from where it connects with your new valve inside.

Step 6 – Loosen Nut Connecting Flapper Rod (Use a Wrench)

Ball-and-arm toilet float in white background

The flapper is a rubber or plastic disk that fits over a hole in the bottom of the tank and allows water to enter when you flush. It’s attached to a metal rod that protrudes from one end of the tank’s interior.

Water flows into this hole from below, filling up the tank and causing it to float up to open another hole at its top end. This hole lets water out of the tank into your toilet bowl when you flush.

You want to use a wrench to loosen the nut that connects the flapper to its rod.

Step 7 – Thoroughly Clean Area Before Installing the New Flapper 

Cylinder toilet float in white background You don’t want dirt or grime getting into the inner workings of your toilet, so make sure that everything around where you will be working is clean and dry before installing a new flapper.

Step 8 – Insert New Flapper into Same Hole

Once you’ve removed the old fill valve, and cleaned up any debris with a rag or paper towel, you want to insert a new flapper into position through that same hole in your toilet tank usually located just below where you removed your old fill valve.

Make sure that it fits securely over its seat inside of your tank before installing it onto its mounting nut or bolt at this point. You may need to attach one end of a chain which should be included with most new fill valves onto this flapper before proceeding with the installation.

Replacing Tips – New Toilet Fill Valve

Replacing a toilet fill valve can be a quick and easy job if you know what to look for. Here are four tips to help make your next toilet repair a success.

  1. Before you begin, make sure that all of the water is drained from the tank. You can do this by flushing the toilet and opening the drain valve at the bottom of the tank or by removing a cleanout plug if your toilet has one.
  2. Use a flashlight to locate and disconnect any wires attached to your old fill valve. There should be two small wires going into the fill valve in addition to a larger black wire that connects to the float itself. If you don’t see these wires, skip this step because they may not be present on your brand of fill valve.
  3. Unscrew or pry off the top cover of your old fill valve with a screwdriver or putty knife if it’s held in place with clips or screws depending on the model. Remove any nuts or retaining rings holding it together if necessary.
  4. Look inside for any plastic parts that might need replacing; if so, remove them now and set them aside. Make sure there are no broken pieces inside that could leak later on down the road!

Final Thoughts

Toilet fill valves are the heart of your toilet. When a fill valve is damaged, it can cause your toilet to leak or not flush properly. Replacing a fill valve is an easy plumbing task that can be done in less than an hour especially if you follow the aforementioned steps.