Are Toilet Tanks Standard?

One of the most ignored pieces of furniture in your home is the toilet tank. Not the toilet bowl itself, or even the toilet seat, but the receptacle that holds the water so that when you flush your solid or liquid waste, it finds its way into the sewer line and away from your house. We may lean on it, cover it, or most commonly, use it as a shelf where we put an assorted number of odds and ends. But when it stops working, that is when it really gets our attention.

In our disposable world, many people choose to replace their entire toilet when it stops working. In most cases it is cheaper, and there are advances in plumbing technology that can be taken advantage of for a more sanitary, water-saving toilet.

A little secret many people do not know about is that toilets simply wear out after a number of years. So attempting to replace your toilet tank should only be done after you know it is the problem.

In This Article

In this article, we will provide a guide to identifying the type of toilet tank that you have, and how to replace it. Many people wonder whether toilet tanks are “standard”, as in, can I replace one water tank type with the other? The short answer is no, but we will explain why below, as well as explain the specific differences in toilet designs that account for this.

Then, we will explain some common problems you may have with your toilet tank, and how you might be able to solve them without needing a replacement at all!

Types of Toilets

In order to know the right type of toilet tank to buy you need to know the type of flushing mechanism you have. There are three basic types:

  • Gravity
  • Pressure assisted
  • Dual flush

Below, we will explain each type, and then explain why they are not necessarily interchangeable. Toilet repair is not always an easy task, but it is essential to do it properly, because the last thing you want is a leak in your bathroom (or worse).

Top 10 Best Toilet Reviews 2020: Helping you find the perfect porcelain

Being prepared with this information will make your decision much easier, and when it is installed you will not have second thoughts about whether you made the best decision for your home.

Learn More Learn More
We earn a commission if you click this link and make a purchase at no additional cost to you.


Most people know about the gravity flushing systems since they are the most common found in homes. The flush lever is on the front side of the tank, and there are two holes in the bottom – one for the water intake pipe and the other that connects to the toilet bowl as the water outlet source. And of course, it uses the power of gravity to generate its flushing power.

Pressure Assisted

The pressure toilet has the same water intake and outlet holes as the gravity unit, but instead of using the pulling force of a gravity toilet there is a single unit placed inside the tank that fills up with water and pushes the contents of the toilet into the sewer line using the water in the tank.

Why Did Toilets Used to be Outside?

The main reason toilets were kept outside, without indoor plumbing and proper disposal of waste, toilets stunk. Gases like Methane could even seep into the house and cause an explosion.

Learn More Learn More
We earn a commission if you click this link and make a purchase at no additional cost to you.

Dual Flush

Dual-flush toilets are becoming increasingly popular, and their design is similar to the gravity toilet. The major difference is that there are two buttons on the top center of the toilet tank, one for liquid waste and one for solid waste. The goal is to conserve water by reducing the amount of water used per flush.

Which Type Do I Need?

Just from a general description of how each of the different flushing systems work, it is clear that there is not a one size fits all approach to choosing a toilet tank.

One rule that applies to all types of flushing systems is that you will have a choice between a one piece model and a 2 piece model. If you choose the one piece model and the toilet tank needs to be replaced, you will have to replace the entire unit. The major consideration in choosing a new two piece tank is making sure the inside will be able to properly fit and install the hardware.

Gravity toilets are your best chance for being able to replace a toilet tank with a universal fit. The reason is it has become an industry standard, so most if not all of the inner pieces you currently have will fit into the new tank without a problem. Just be sure to check and see if your toilet has any unique features. There are also toilet tank models that attach to the wall with screws. If you judge that there is no longer a need to have wall-hung toilets, then you can replace it with a universal model.

Do Toilets Come In Different Heights?

People come in all shapes and sizes and because of that there are some toilets that are higher, and some that sit lower on the floor. This is why houses with more than one bathroom usually have master bathrooms and children's bathrooms.

Learn More Learn More
We earn a commission if you click this link and make a purchase at no additional cost to you.

All pressure assisted toilets have one thing in common when it comes to replacing a toilet tank: the tank you choose must comfortably fit the water collection unit inside the toilet tank. This may require you to buy a replacement tank only from the manufacturer. Also be sure to make sure it is the same model. Pressure assisted tanks can be placed on the floor or rest on the toilet as with the standard gravity types.

Dual flush models are much the same as gravity models except you need to make sure the top of the tank has an opening for the flushing mechanism.

So the best answer to the question is it depends. The more standardized your unit is, as with a gravity toilet, the better the chances are you can find a replacement tank without any trouble. Since dual flush systems are becoming more popular, they rank second, and pressure assisted unit may require some searching.

So whatever type of toilet you have, keep the owner’s manual handy and don’t forget that regular maintenance can significantly reduce the number of problems that can occur with the tank. We wish we could say that toilet tanks are all standard, because that sure would make life easy. However, if there’s one thing to take from this, read the manual and know what you are dealing with from the start. If you learn how to replace your toilet tank right as you are installing it, you can save yourself a lot of trouble in the long run.

How Did Toilets Work In Castles?

 Some castles were built to where the moat would feed into a running river, acting as a flush toilet and removing the waste from the castle. And then, there were those who had to clean the pits.

Learn More Learn More
We earn a commission if you click this link and make a purchase at no additional cost to you.

Common Issues

Throughout this article, we have mentioned that there are several potential problems that could lead to a tank needing replacement. Therefore, it might be helpful to run down a few of the more common problems. If you are aware of what could potentially go wrong, you’ll know what to look out for and how to avoid it. Some of these problems don’t even require a tank replacement at all.

Toilet Flushes On Its Own: If you have ever noticed your toilet flush seemingly out of nowhere, you may have a problem with a specific part within the toilet tank. This issue is caused because the toilet tank is slowly leaking water into the toilet, emptying itself, and then refilling on its own, as if it had been flushed.

Luxe Bidet Neo 120 Fresh Water Non-Electric Mechanical Bidet

With a sleek design and high-quality parts, our bidet attachment will give your bathroom a next-level look. Constructed with high-pressure valves with metal/ceramic cores and steel hoses instead of plastic.

Check Price On Amazon Learn More
We earn a commission if you click this link and make a purchase at no additional cost to you.

While this may seem like an issue with the toilet tank, it is actually generally a cause of the flapper. The flapper is meant to seal the tank from leaking water into the bowl. Usually, if you clean the flapper, the problem will resolve, and you won’t need a new tank at all!

Water “Trickling” In Tank: If you constantly hear water trickling into your toilet tank, you may also think there is something wrong with the tank. This is not always the case, often it is the result of water coming in through the inlet valve. It may also be caused by the refill tube being inserted too far into the overflow tube. Finally, it may be the result of a malfunctioning ballcock assembly.

As you can see, these problems do not require replacing the tank. In fact, often your toilet simply has problems with the mechanisms within it. Of course, this is frustrating in its own right, but is worth looking into before you splurge on an all-new tank. Unless your tank is noticeably broken or leaking, you can likely find the solution somewhere else.


So there you have. The simple answer to our question proposed in the title is – it depends. It really will depend on which type of tank you have, and how standardized your unit is. Therefore, our best advice for you is to familiarize yourself with the tank upon installation. What better time to learn about the specifics of your toilet than when you are already installing it anyways? Not only will this help you deal with having to replace a tank if need be, it will help you solve many problems should they arise.

Understanding How Toilets Work

You might want to start designing your dream home but if you do not know how bathrooms work, you would be going wrong somewhere. Understanding how toilets work can help you create the right bathroom design that you and your guests would love.

Learn More Learn More
We earn a commission if you click this link and make a purchase at no additional cost to you.



  1. Joe b
    • Jason Wilson
      • Tammy Morris-Traylor
  2. GFR
    • Jason Wilson
      • Fred Kerrick
  3. Harold CHORNY
  4. Wayne Floyd
  5. Wayne Floyd

Leave a Reply