Are Toilet Tanks Interchangeable? (Quick Explanation!)

So, your toilet tank looks old and cracked, and it crosses your mind, ‘I can fix this.’ But since there are many options, you cannot help but wonder, ‘are toilet tanks interchangeable?’

Generally, most toilet tanks are interchangeable if they share the same flushing system and brand. Additionally, they have to be the same size to fit the existing pipework.

We’ll talk about the flushing systems and how you can identify them. Plus, we’ll look at some of the leading toilet tank brands and their ability to allow the interchanging of toilet tanks.

Moreover, I’ll help you measure your toilet tank when you want to get the most befitting replacement.      

Let’s get started!

are toilet tanks universal

When Are Toilet Tanks Interchangeable

Essentially, here are two instances that make toilet tanks interchangeable:

  • When toilet tanks have the same flushing system
  • When the toilet tanks share the same brand

And once you accomplish the above two instances or steps, you should look for a toilet tank that matches your existing size. That makes it the third step.

Let’s discuss all three steps.

Step 1 – Same Toilet Tank Flushing System

If you get wrong here, the chances are that the replacement toilet tank won’t fit. Typically, toilet tanks are only universal and interchangeable within the same flushing system.

That brings us to the following three toilet flushing systems:

a) Gravity Flush Toilets

Gravity flush toilets are the most typical toilet types in most homes. As the name suggests, these toilets employ gravitational force to push water down the bowl and into the sewer line.

But since the water doesn’t employ any unique mechanism but is just Gravity-dependent, these toilets are the most prone to clogging. As a result, most homeowners are slowly opting out and considering other options.

b) Pressure-Assist Toilet Tanks

Pressure-assist toilets come with the same setup as gravity flush toilets. But unlike gravity flush toilets, they don’t depend on gravity but a pressure-assisted mechanism to flush water down the bowl.

Usually, you activate the flushing mechanism when you press the flush button on top of the tank’s lid.

Overall, these toilets are the most efficient for cleaning and flushing down. Unlike gravity flush toilets, pressure-assist toilets rarely clog, all thanks to their built-in pressure assist mechanism.

c) Dual-Flush Toilet Tanks

Dual flush toilets feature a set of two buttons that you press when you want to flush the toilet. Usually, the two buttons dictate how much water runs down the bowl into the sewer.

The tip here is to look for a replacement toilet tank with two flush buttons on the lid if you have a dual-flush toilet. Once you get it, you can go ahead to find the right brand and size, as I explain next.

Note that one of the two buttons is for flushing more water (in the case of a poop), and the other is for less water (in the case of a pee). That generally helps you regulate your water usage and save on water bills.

Are Toto Toilet Tanks Interchangeable

Step 2 – Same Toilet Tank Brand

It’s not just enough to find a replacement toilet tank with the same flushing system as your old toilet tank. Sometimes it is but not always. So, instead of taking a gamble, go ahead and look for a matching brand.

You can tell the tank brand name by looking inside the tank, under the lid, or below the bowl.

Some of the most typical toilet tank brands include:

  • American Standard
  • Kohler
  • Gerber
  • Glacier Bay
  • Toto

Are American Standard Toilet Tanks Interchangeable?

As discussed earlier, it’s a matching brand name and a matching flushing system and size that makes toilet tanks interchangeable. That’s the case with American Standard toilet tanks, and all of them come with a model number under the lid.

You can use the model number to find a perfect replacement. Alternatively, you can manually calculate your old tank’s measurement and look for a matching American Standard toilet tank.

Are Kohler Toilet Tanks Interchangeable?

When it comes to Kohler toilet tanks, their replacement parts are interchangeable with Fluidmaster parts. However, that doesn’t mean that all Kohler tanks are interchangeable.

Like every brand, Kohler toilet tanks are toilet specific. They are only compatible with Kohler bowls, and you must pick a replacement with the same flushing system as your old tank.

More importantly, you should get the tank’s size right and ensure it’s compatible with the pipes.

Are Gerber Toilet Tanks Interchangeable?

Very few Gerber toilet tanks are interchangeable with other brands. But still, the replacement and your old tank have to match in size and flushing system.

Overall, you can check for the tank’s model number inside and Google-search it to find a replacement online. Then again, you can inquire directly from the manufacturer.

Are Glacier Bay Toilet Tanks Interchangeable?

When it comes to Glacier Bay toilets, every part is interchangeable with a generic matching option other than the tank, lid, and toilet bowl. So, no, you cannot replace a Glacier Bay toilet tank with another brand but only its sibling.

But even so, the two (old and new) must match in size and flushing system.

Are Glacier Bay Toilet Tanks Interchangeable

Are Toto Toilet Tanks Interchangeable?

Toto toilet tanks are generally interchangeable with their kind. However, the replacement tank has to match the old tank’s size, flushing system, valve outlet, and bolt spacing.

You’ve to consider all these considerations when searching for a replacement Toto toilet tank.

Step 3 – Similar Toilet Tank Size

The third instance, which is just as important as the first two, is when the replacement tank (which is of the same flushing system and brand as your old tank) matches the size of your old tank.

In that case, you have to measure its size, which you can do with a measuring tape by following these steps:

  • Use the measuring tape to measure the tank’s length, depth, and width and write them down
  • Also, measure the fixtures and the pipes. If not, you’ll be compelled to replace them when you bring in a new toilet tank

Alternatively, you can tell what size to get by using the serial number of your old toilet tank.

All toilet tanks have serial numbers, which you can find inside them. So, you can Google Search the serial number, and the tank’s size and replacement options will pop up on Google searches.

Important Note:

Having touched on the fixtures, it’s worth mentioning that you also have to consider the size of the bolts on the toilet tank and their holes. Like the toilet tank, the bolts are only interchangeable if they are the same size.

Common bolt sizes include 5/16th inch and 14th inch, which most people call the standard sizes. But before you can think of replacing the bolts, look at them to see if they are rusty.

If they aren’t, then keep them to use them when you fit the new tank. But if the bolts are rusty, you must shop for new ones alongside the replacement toilet tank.

Are Toilet Tanks Interchangeable Between Brands

People Also Ask

1. Are Toilet Tanks Interchangeable Between Brands?

While most people assume that just because toilet tanks have the same brand name that they’ll fit, it’s often not the case. The toilet tanks also have to feature the same flushing system and should match in size to be interchangeable.

2. Are Toilet Tanks and Bowls Interchangeable?

Toilet tanks and bowls are only interchangeable when they are of the same brand and enjoy the same flushing system. Moreover, the layout of the bolt holes of the old and the new parts should match.

Note, however, that this is unlikely to happen between an older and newer model as the designs change quickly over time.

3. Are Toilet Tanks Universal?

Toilet tanks are universal and interchangeable only when they share flushing systems and brand names. In such cases, you can easily replace them with something similar if the size matches.

4. Can I Put a Different Tank On a Toilet?

You can only put a tank on a toilet if it has the same flushing system as the toilet. Also, it’s advisable to do it if they share the same brand name as different brands employ different designs, which may not be compatible with others.  

5. Can You Mix and Match Toilet Bowls and Tanks?

It’s generally wrong to mix and match toilet tanks and bowls as different brands have different designs and sizes, which may not be companionable with others. So, the two sets may end up not fitting, which could be a waste of effort and cash.

6. How Do I Know Which Toilet Tank to Buy?

You can know which toilet tank to buy by first looking for an option with a flushing system that resembles your toilet. After that, look for the same brand name, and lastly, identify a size that matches your toilet.

Alternatively, use its serial number to find a replacement toilet tank online or inquire from the manufacturer.

7. Are Toilet Tanks Standard Size?

Toilet tanks are only standard size within the same brand name and flushing system. In such cases, the toilet tanks are interchangeable. But still, they have to match in size and be compatible with your existing pipework.

8. Can You Put a New Tank On an Old Toilet?

With the design technology for toilet tanks fast-changing, finding a compatible tank replacement for an old toilet is not easy. That, however, doesn’t make it impossible.

Provided you get a replacement with the same flushing system and brand name as your old tank; you can replace it.

Are Toilet Tanks Interchangeable? Final Remarks!

The reality is that the term standard only exists within a specific toilet flushing system, brand name, and size. If your new toilet tank has the same trio as your old one, then it’s a perfect replacement.

So, consider that before splashing your money on a new toilet tank. However, don’t forget about the pipes and bolts as they also matter.

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