What is a Cassette Toilet? How Does It Work?

Last Updated on August 30, 2023 by toilethaven

Cassette toilets are often confused with portable camping toilets. They almost work the same way but are a little different. So, what is a cassette toilet, and how is it different from a portable camping toilet?

A cassette toilet is an RV toilet permanently installed with a detachable portable holding tank with wheels like a suitcase. It is installed closer to the wall of the RV or boat to allow the holding tank to be easily removed and reattached through an exterior door.

Cassette toilets have smaller holding tanks than the traditional RV black tanks and will, therefore, need frequent emptying/dumping. Thetford, which is probably the largest manufacturer of cassette toilets, makes their cassette toilets with a holding tank of 4.75 and 5.1 gallons in capacity.

The main advantage of a cassette toilet over a traditional RV black tank toilet is that you can dump your waste at any place as long as there is a flush toilet, while you would need a dumping station to empty your RV’s black tank.

The disadvantage of a cassette toilet over a traditional RV toilet is the frequent dumping. The waste tank can also be a little heavy for some people. Another thing is that you are in very close contact with the waste, which is less than ideal for some people.

Cassette toilets have been widely used in Europe and are only catching up with the North American market. Some people like them, while others will not even consider them. There are no fence-sitters.

How a Cassette Toilet Works

  • A cassette toilet system consists of the toilet, holding tank, and the water source. The holding tank is normally located under the toilet so that the waste can flow downward with the help of gravity.
  • Between the bowl and the holding tank, there is a sliding valve. The sliding valve prevents waste leakage during transportation and helps contain the smell.
  • Due to the limited space in most RVs, a cassette toilet is designed in such a way that it can pivot/rotate around the bowl. This is especially great for people with long legs since you can turn the toilet towards the shower.
  • The flushing button is normally mounted on the wall, mostly adjacent to the level indicator. The level indicator signals to you when the holding tank is full so you can empty it.

How to Empty a Cassette Toilet

  • First, make sure that the toilet bowl is empty and that the sliding valve is closed.
  • Open the exterior door, pull the latch, and slide out the holding tank.
  • Once the holding tank is out, you can carry it or roll it. It has wheels and an extendable handle.
  • Proceed to the restroom or dumping station.
  • Point the pour-out spout downwards on the dumping hole and start emptying.
  • Rinse the tank a few times with clean water.
  • Slide the holding tank back in the RV.
  • You may opt to lock the cassette toilet holding tank door if you suspect it might be stolen.

Best Cassette Toilets

At the moment, it is not very easy to get a cassette toilet in North America. They are, however, very common in Europe. Nonetheless, the following are what I would consider the best cassette toilets:

1. Thetford Cassette Toilet C200


This cassette toilet bowl revolves around 180 degrees to economize on space but can also be locked down in position by pressing down on the seat. These are some of its features:

  • 4.75 gallons waste tank capacity.
  • Waste tank level indicator.
  • Portrait or landscape service door orientation.
  • Waste tank with extendable handle and wheels for dumping.

There are three models of the Thetford C200 cassette toilet. Let us have a look at how each differs from the other.

The C223-S Cassette Toilet

  • Directly connected to the RV fresh water tank.
  • Electric fresh.
  • It is wall-mounted.
  • Dimensions: 22.875 inches depth, 14.375 inches width and 19.375 inches height.

The C223-CS Cassette Toilet

  • Directly connected to the RV fresh water tank.
  • Electric flush system.
  • The back cover hides the plumbing.
  • Dimensions: 22.875 inches in depth, 15.5 inches in width, and 21 inches in height.

The C224-CW Cassette Toilet

  • Own a 2.37-gallon freshwater tank.
  • Manual flush system.
  • Dimensions: 22.875 inches depth, 15.5 inches width and 28.625 inches height.

3. Thetford C402C Cassette Toilet


Let us look at the features that make this a worthwhile cassette toilet:

  • Bench-style cassette toilet.
  • LED waste tank level indicator. It can be installed on the left or right.
  • Waste tank with wheels and retractable handle.
  • Automatic pressure release vents the waste tank.
  • Electric push button.
  • Removable seat and cover for easy cleaning.
  • 5.1-gallon waste tank capacity.
  • 4-gallon waste water tank.
  • Dimensions: 15.75 inches depth, 26.375 inches width, and 18 inches height.

3. Dometic CTS 4110


The Dometic CTS 4110 is another great cassette toilet. It can rotate 90 degrees in both directions to make use of the available space. Its features and specifications are:

  • Scratch-resistant, high-quality, lightweight ceramic bowl is dirt-repellant and easy to clean.
  • Ergonomic toilet seat.
  • Optimized vacuum breaker increases flush power.
  • Waste tank level indicator.
  • Dimensions: 20.86 inches in depth, 15 inches in width, and 26.46 inches in height.

Cassette Toilets Vs. Composting Toilets

Composting toilets are a type of dry toilets that biologically break down human waste into an organic fertilizer. The main difference between a composting toilet and a cassette toilet is that while a cassette toilet needs water for flushing, composting toilets don’t need water.

The major concern most people have with composting toilets is the smell. I have lost count of the many times I have had someone ask me, “Do composting toilets smell”?

A decent composting should not smell. When most people hear about composting toilets, the first thing that comes to mind is some ugly structure that looks worse than a pit latrine. The truth of the matter is that modern composting toilets are beautifully designed and sleek pieces that will perfectly match any modern bathroom style and decor.

Composting toilets have a way of separating the solids from the liquids. While the liquids are frequently emptied, the solids are left to decompose. Sawdust or peat moss is added to the solids waste bin to take care of the odor and quicken the decomposition process.

The good thing is that you can use the composting toilet many times before emptying the solids. Another interesting thing is that you don’t need to throw away solid waste as it is a good fertilizer for your garden.

Good composting toilets have a fan that takes out the odor from the solid waste bin and channels it outside. The fan also makes the solids dry, which quickens the decomposition.

When it comes to composting toilets worth buying, I know of three brands. These are:

  • Nature’s Head composting toilets.
  • Separett composting toilets.
  • Sun-Mar composting toilets.

The Nature’s Head composting toilet is the best composting toilet and would, therefore, be a good alternative to a cassette toilet. Let us see what makes it a worthwhile alternative.

Nature’s Head Composting Toilet

Nature's Head Self Contained Composting Toilet...
  • No one - and I mean no one - will beat my customer service and individual support
  • Easy to install by any reasonably handy person.
  • Absolutely No Odor. No Maintenance. 5 Year Warranty.

The Nature’s Head composting toilet was originally designed for use in the marine industry, but it quickly became a hit in all of the other leisure activities.

It has a very simple but effective design. The toilet bowl and seat are installed on top of the solid waste bin, while the urine bottle is at the front. The solids and the liquids mustn’t mix, so the gentlemen are always advised to remain seated during the entire process.

Just like any other composting toilet, you start by putting peat moss in the solid waste bin before using the toilet for the first time. This toilet has no bad odors, which is one of its strongest propositions.

There are two variations of the Nature’s Head composting toilet. Depending on your space, you can go for the one with a spider handle or the one with a standard crank handle.

The former is better for people with limited space, while the latter is for those for whom space is not a problem. The handles mix the waste with the peat moss for faster decomposition and odor elimination.

You can choose to have the fan running for 24 hours or switch it off. According to Nature’s Head, if you are in an area with free air movement, you can opt to have the fan off as long as the hose is vented upwards.

Emptying this toilet is so easy. The bowl is attached to the solids waste bin using two side latches. Just unlatch the bowl and proceed to empty the bin. The latches and other hardware are made of stainless steel and will not corrode.

Comfort-wise, the toilet is not too short, and it also has an elongated toilet seat, which is as good as the one you have in your flush toilet at home. 

To show you how awesome this toilet is, you can use it up to 90 times without emptying the solid waste bin. To put that into perspective, two people using it will need to empty it after 4 to 6 weeks of full-time use.

Its dimensions are 22 inches in depth, 20.5 inches in width, and 21.7 inches in height. It comes with a 5-year warranty.

Cassette Toilets Vs. Porta Potty


Porta potties, or portable camping toilets as their name suggests, are portable and can, therefore, be transported from one point to another, unlike cassette toilets, which are fitted on the RV or boat. Portable camping toilets consist of 3 parts: the bowl and seat, the fresh water tank, and the waste tank/holding tank.

The holding tank is detachable to help you dump and clean the waste. These portable toilets are what are called flush-type portable camping toilets. Other types of portable camping toilets are bucket camping toilets and collapsible camping portable camping toilets.

We will, however, focus on the flush-type portable camping toilets as they are the ones that resemble cassette toilets the most and are frequently confused.

How a Portable Toilet Works

  • The bowl: This is normally at the top of the toilet. Although it is not as big as your flush toilet bowl, the best portable toilets try to make it comfortable and a little high. It comes with a seat and lid that snaps tightly on the bowl.
  • Freshwater tank: The freshwater tank is normally located between the bowl and the holding tank. It holds the water necessary to flush the toilet. Freshwater tanks also have a removable cap at the top to help you add fresh water to the tank.
  • Sliding valve: This valve is installed between the freshwater and waste tank. It prevents the toilet from leaking and contains odor inside the waste tank. Pull the valve handle outwards to connect the bowl to the holding tank when you want to use the toilet.
  • Wastewater tank: The wastewater tank is bigger than the freshwater tank and is the one at the bottom. It is joined to the other parts of the toilet using side latches. A chemical that breaks down the waste and removes odor is placed in the holding tank. Once the holding tank is full, the waste is dumped via a spout and also rinsed severally.
  • After dumping the waste, the chemical is added to the holding tank, which is reattached to the other part of the toilet.

These portable toilets are decent when being used as RV toilets. Again, not everyone will like them. Some people are just happy using the usual black tank RV toilets.

I like that you don’t need to permanently install the portable camping toilets in your RV, as is the case with cassette toilets.

So, if you were to go for the portable camping toilet as an alternative to cassette toilets, which one should you go for?

Let us have a look at the best portable camping toilets.

1. Thetford Porta Potti Curve

Porta Potti White Thetford Corp
  • [VERSATILITY]: Award-winning, top-of-the-line portable toilet, suited for RVs, boats, trucks, vans, healthcare, medical, camping and even off-the-grid lifestyle, with a 4 gallons fresh water tank...
  • [DESIGN]: Sleek, modern, and homelike look, Porta Potti Curve comes with a comfortable seat height, increased bowl size, and battery-powered flush
  • [FUNCTIONALITY]: Easy to use and clean, Curve has an ergonomic carrying handle, an integrated toilet paper holder, and a tank level indicator

This is, in my opinion, the best portable camping toilet. It is a modern, sleek toilet that almost resembles a normal flush toilet. The colors available are white and gray.

It has a 4-gallon freshwater tank and a 5.5 wastewater tank, sufficient to last you for up to 50+ flushes. What I love about this toilet is that, unlike other portable toilets where the sliding valve handle pulls outwards, this one slides along the toilet’s body.

The one thing that is hard to get when it comes to portable toilets is a good seat height. This is especially bad if you have bad knees. Fortunately, the Thetford curve has a decent height, like a flush toilet, and you will not need to squat too low.

I was impressed when I saw its integrated toilet paper holder. It is concealed inside the toilet’s body and only displayed when you are ready to use the toilet. Another interesting feature is the ergonomic carrying handle, which makes it easy to carry it from one point to another. It has a hold-down kit for mounting it on the floor during transportation.

Once the holding tank is full, a level indicator on the side of the toilet will let you know it’s time to dump the waste. The wastewater tank has a rotating spout that lets you dump the waste without the risk of it splashing back on your face.

I have mixed feelings about the toilet’s flushing system. The Curve uses a battery-powered flushing system. At any one point, it will need 6 AA batteries to flush. While the flushing is great, what would happen if your batteries start running low while you are away and have no extra ones?

Thetford Porta Potti Curve has a depth of 17.7 inches, a width of 15.2 inches, and a height of 17.6 inches.

2. Dometic 301097206 970 Series Portable Toilet

Dometic 1223.0154 301097206 970-Series Portable...
  • PORTABLE AND POWERFUL FLUSHING: Dometic Portable Toilet is an excellent choice for camping, outdoor events, RV trips, or any situation that requires a convenient and hygienic portable toilet. The...
  • HIGH-STRENGTH CONSTRUCTION: Made with high-density polyethylene, this toilet can withstand harsh environments and is designed to last. You can drop it or stand on it, and it will still work great. The...
  • COMFORTABLE AND SECURE: With an adult-size seat and lid, this portable toilet provides comfort and safety. The side latches lock firmly for added security. You can travel with peace of mind knowing...

The Dometic 301097206 970 portable toilet is another great toilet you may install in your RV as an alternative to a cassette toilet. It has a 5-gallon wastewater tank and a 2.6-gallon freshwater tank. There is also a 5-gallon freshwater tank toilet model, but as expected, it is a little expensive.

This toilet works the same way as the Thetford curve porta potty, but it has a flush button instead of being battery-operated. In order to flush effectively, you will need to pressurize the flushing water first.

On top of the freshwater tank is the small hand-operated pump. Pump for a minimum of 15 times to create pressure in the tank. Next, pull out the sliding valve to expose the holding tank to the bowl.

As soon as you are done doing your business, push the flush button for flushing to occur. Push the sliding valve back to contain the smell.

To get the guesswork out of the way, the holding tank has a level indicator that precisely tells you when to empty it. A side latch on the side of the toilet will help you detach the holding tank from the toilet for dumping.

Before proceeding to the dump, check for a dial on top of the holding tank. Set the dial to “OPEN”. This opens a hole, pushing air inside the tank and creating a smooth emptying process through the long spout.

The holding tank’s design is meant to prevent backsplashing. After dumping, turn the dial to “CLOSE” and attach the tank to the toilet.

If you wish to install this toilet on your RV permanently, Dometic will offer you the necessary mounting bracket. It is, however, sold separately from the toilet at an extra cost.

All in all, this toilet works well and looks good too. Its dimensions are 15.25 inches in depth, 13.2 inches in width, and a height of 12.5 inches.

Cassette Toilet Vs. Black Tank

Two main differences exist between a cassette toilet holding tank and a traditional RV black tank. These are the portability and the capacity of each tank.

Cassette toilet holding tanks, as we have seen, are removable and portable, while an RV black tank is permanently installed on the RV.

On the issue of capacity or volume, cassette toilet holding tanks have a small capacity of about 5 gallons or less. On the other hand, black tanks have a relatively more significant volume of, say, 25 gallons.

This, therefore, means that you will need to empty a cassette toilet tank waste tank more frequently than a black tank. This is the main reason why folks who have always owned traditional RV toilets are hesitant about installing a cassette toilet.

They don’t imagine themselves emptying a toilet every 2 or 3 days. You also have to carry the waste, physically dump it, and clean the holding tank, making it even less appealing to these people.

Not everyone, however, dislikes cassette toilets. I have come across couples and families who swear it is the best thing that happened to their camping lives.

The main advantage of a cassette toilet is that dumping the waste is super quick, and you can almost dump it anywhere as long as there is a restroom. A black tank will need you to find a dedicated dumping station to dump the waste.

I don’t think many people would be comfortable emptying their black tank in their home toilets. With a cassette toilet, on the other hand, you can comfortably empty it in your home toilet without a mess.


I reckon the main advantage of dumping waste from a black tank is that it is less gross, and when you empty it, you can wait for a long time without needing to empty it again.

I honestly don’t think that one system is better than the other. As we all know, people have different tastes and preferences, especially when it comes to camping. You should always go for the systems which will best suit your needs.


Cassette toilets have taken a long to get into the North American market, but they are finally here. Some people liked them from the onset, while others did not even consider them. For this reason, I am convinced they will not make the traditional RV toilets obsolete.

It will, however, be very interesting to see what percentage of the market share they will have taken up in the next 20 or so years.