How To Replace A Toilet Tank Fill Valve (In Just 9 Steps)

One of the most irritating things to happen in your bathroom is when your toilet water keeps running and running and does not seem to want to stop! Other than the annoying aspect of it, this could be indicative of a leaking toilet.

How To Replace A Toilet Tank Fill Valve (In Just 9 Steps!)

Luckily though, you can replace the toilet tank fill valve which should solve your problem. But some people might be unaware of what to do here.

But don’t panic – we’ve done all the hard work for you. We’ve listed the nine steps that you need to follow in order to replace a toilet tank fill valve, and it’s not as complicated as you might have thought!

So, if you’re ready to learn a lot more – then read on and discover the solutions!

What Is A Toilet Tank Fill Valve?

Let’s start off by examining what exactly a toilet tank fill valve actually is. Essentially, this is the valve that controls the flow of the water, which then allows the water to fill and refill both the tank and bowl, every time you flush the toilet.

However, older toilets use a ball-cock system which is pretty much like a plunger in the way that it operates.

Modern toilet systems however will have their tank fill valve inside of the tank, and typically these will work fine for a long time.

Having said that, plumbers recommend that people should look for a replacement valve every five years or so for maximum efficiency.

Why Would A Toilet Tank Valve Stop Working?

Before we look at how you could replace a toilet tank valve, we should explore the potential reasons why the original toilet tank valve stopped working in the first place.

Wear And Tear

Over time, it’s common for a toilet tank valve to stop working through the expected wear and tear. Normally, this is due to a buildup of dirt and debris which eventually causes the system to stop working.


Another common reason why the valve would stop working is due to damage. Sometimes, this is caused by a heavy object falling onto the outside basin, but more often than not it is damage caused by someone “fiddling” with the valve, perhaps to try to fix or inspect it.

It’s not always a good idea to do this unless you know what you are doing and what you are looking for.

Poor Fitting

Another reason why your valve might have stopped working is because it was wrongly fitted in the first place. This is generally quite clear within the first few times that you use the toilet, like when you move into a new place.

Replacing Your Valve – The 9 Steps

How To Replace A Toilet Tank Fill Valve

Let’s now examine the 9 steps for replacing your toilet tank valve in the easiest possible way.

You Will Need

Before you begin, be sure that you have the following items:

  • A sponge
  • An adjustable wrench
  • A float-cup fill valve assembly

One thing to note before you start though is to be sure that you have all of the correct and necessary parts.

It’s a good idea to buy a universal valve kit assembly, but some toilets will not accommodate it, so try to ask a professional if you are unsure.

Instructions Step By Step

How to replace a toilet tank fill valve

  1. Tuen off water supply

    The water supply is located under the toilet tank. Turn it off and then flush the toilet and sponge-dry the tank entirely.

  2. Remove locknut

    Using an adjustable wrench, release and remove the top locknut for the fill valve which is under the tank.

  3. Remove fill valve

    Remove the rest of the fill valve with your wrench.

  4. Release the clip

    Release the clip of the refill tube and take out the fill valve.

  5. Adjust height

    Alter the height of your new fill valve and fit it to the tank by twisting it from the base. Your kit will have instructions on how to do this step.

  6. Insert fill valve

    You now need to insert the threaded base of the fill valve through the bottom hold of the tank and then secure it with your locknut.

  7. Reclip

    Reclip the refill tube to the overflow tube.

  8. Reconnect top supply

    You now have to reconnect the top supply slip nut to the system. Remember to switch the water supply back on once you are absolutely sure that the valve is fitted correctly and tightly and then allow the water to fill the tank.

  9. Flush

    Flush your tank and adjust the float to the specifications required for the right water level.


If you are having difficulty with these steps, it’s always a good idea to contact a professional to assist you. This is particularly important if you find your tank is not refilling at all, or the original problem has returned.

The system might be leaking or you might have further damage that you have not noticed. Avoid trying to fix the problem yourself if you are still unsure.


Once you are sure that you have done everything right and the system is working as it should be, you need to now keep an eye on your toilet (not literally) over time.

For the first couple of days, you should always listen out for strange sounds or continuous running water. As always, try to keep the surroundings of your toilet clean and free of debris and other loose dirt.

You should find that the new toilet tank fill valve lasts for a number of years now, but it’s recommended that you find a replacement in five years after this, or before if you need to.

If you discover that your toilet tank fill valve is not lasting very long, you should contact a professional in this circumstance. Once again, this could be indicative of a more serious problem with your toilet system.

Is All Of This Expensive?

No, you can source everything you need for a very budget friendly price. However, the costs will increase if you have damaged the system and need to call out a professional, as it will then be down to their personal charges and costs.

Sometimes, it is better calling them out right away rather than trying to fix the problem yourself if you are totally unsure!

Final Thoughts

Toilet tank fill valves will need replacing from time to time, but with this know-how and the right confidence – you should be fine!

Adrienne Carrie Hubbard
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