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Cassette Toilet Emptying in Campervan / Helpful Video Tips

Cassette Toilet Emptying in Camper VanSince purchasing my Hymer Aktiv campervan, I've received so many questions about the cassette toilet that came with the campervan. It's an anomaly here in North America; however, European countries primarily use the cassette toilet instead of the traditional black tanks. 

Cassette toilet emptying in a campervan is much easier than a traditional black tank. I'm going to go through the pros and cons of a cassette toilet, how I use the toilet, how it's different than a black tank, and how NOT to empty the cassette cartridge – because there is definitely a way NOT to empty it!

In my cassette toilet review, I go over how to use the toilet, the swivel operation, the full tank sensors, how to empty the cartridge, the blade operation, using chemicals to keep the odor down, and where to dump the tank and how often.

I’m going to explain to you the entire process on how to operate and empty a cassette toilet so you can determine if a cassette toilet is right for you over the traditional black tanks. 

Why Hymer Used a Cassette Toilet Instead of a Black Tank

My Hymer Aktiv campervan came with a Thetford cassette toilet instead of the black tank to aid in keeping the weight of the campervan down. Since it's a Class B RV and considered a campervan, you already have limited space and storage, especially if you are planning on traveling full-time.

In order to maximize space in the campervan, installing a cassette toilet instead of the traditional black tank makes sense. Not only do you reduce the load of the vehicle, reduce the space needed for the sewer tank (cassette toilet in this case), but you also don't have to carry the sewer hoses, commonly called “stinky slinky”. Hoses associated with black tanks can store in a compartment or container where it cannot touch anything else due to possible contamination. Well, and then there's the smell. Yuck!

Hymer is a brand that is very popular in Europe, and it has taken the philosophy of the cassette toilet and brought it here to North America in its campervan lines to date.

Let's Talk Pee & Poop

An interesting thing happens when you first start RVing that is different than owning a home especially if you boondock or dry camp more than staying at RV parks.

You become acutely aware of your water consumption and – well – how much you go #1 and #2. Okay, so maybe you don't want to talk about or hear about #1 and #2 and think it's gross. Well, I would agree that it can be gross in certain situations, but it's something we all do and is very typical. Plus, when you start to RV, you'll find that we ALL talk about it.

In a traditional home, where you connect to city water and sewer, you might not think about your use as much for sewer and water. You might be conservative, but you still have an endless supply of water at your fingertips by turning on the handle and letting the water flow.

You can go to the bathroom at all hours of the day, every day, all day, whenever. You get my point – right?

In an RV, you become intimately involved with understanding how long you can stay out boondocking and dry camping without needing to empty the cassette toilet or a black tank. In my old RV, the black tank was 23 gallons, and I could wait three weeks before needing to empty the black tank.

That's not the case now. Now I must empty every 4-5 days. You'll find out why coming up.

How the Cassette Toilet Operates Inside the Campervan

You might have seen from my van tour how small the bathroom is and that it's a wet bath, which means the shower and toilet are all-in-one. I don't take showers in there, because it's just a pain. I have to move things around and then dry everything off afterward. Instead, I use public showers, go to the gym, or truck stops. It's just easier. That's a whole other topic that I can post on later.

Hymer Aktiv bathroom

No Toilet Paper

While I do in fact use toilet paper, I do not flush it down the toilet. I didn't flush it in the black tank toilet either in my other RV. This way it keeps anything from getting clogged and saves on capacity in each tank before having to empty.

Instead, I dispose of the toilet paper inside of a garbage can with a lid on it and then empty it fairly often.

#1 & #2 in the Cassette Toilet

Some RVers have a cassette toilet where they prefer only to go #1 in their toilet to cut down on the number of times they need to empty and also having to clean it. I prefer to use it for both #1 and #2 only because I'm a solo traveler and only need to empty it every 4-5 days and it's just more convenient that way. As long as you use the chemicals made for the cassette toilet, you shouldn't get any smell from it.

I don't typically like to use chemicals, but I was thinking that when you are in a home, and the city manages your sewer for you – they are also treating the waste with chemicals to help break it down, which is precisely what I'm doing.

So for now, I'm just using the cassette toilet like I would any other toilet, except for the toilet paper usage.

How Often Do I Empty the Cassette Toilet

I generally am emptying the cartridge every 4-5 days of usage; however, that can depend on where I'm at in the city or in the wild. For example, if I'm doing a bunch of errands and I'm in and out of stores, I'll use the store facilities to go to the bathroom.

If I'm out in the wild, I'll go #1 outside using my pStyle urination device for women which saves me from having to empty, and I can boondock longer.

One of the advantages to those who go #1 in their cassette toilet is that they can empty their cartridge in the wild – as long as it's only urine with no chemicals.

Swivel for Comfort

Since this is a small space in the campervan, the cassette toilet has an added feature that it can swivel to the left and right. When you are sitting down on the toilet, you can swivel the toilet to a position that is comfortable for your legs.

You can also swivel it all the way to the right if you use the wet bathroom for showers so you'll have more space to stand up or sit down to shower.

Flushing the Toilet

Just below the toilet seat, in the front, is a grey lever that you can move to the left and right to flush the toilet. The lever opens up the bottom of the toilet where the blade is at and empties into the cartridge below.

Once you empty the toilet bowl, you hit the blue button on the wall behind the toilet, and it will add water to the toilet bowl to rinse it off. You must have the water pump on for this to operate correctly.

Tank Sensor Button

The tank sensor button on the Thetford cassette toilet only shows when the toilet is full. The sensor function is different than the black tank which will show you how full it is at all times. However, I found in my other RV that those sensors would get dirty and not always be accurate.

How to Empty the Cassette Toilet Outside of the Campervan

On the driver side door is a doorway that opens with a key to the box cartridge on the inside that holds the waste. Once you open the door, you pop up the orange handle to release the cassette toilet cartridge and then pull it out from the side of the campervan.

Opening Cassette Toilet Door

Thetford Cassette Toilet

Screw open the lid to the cartridge and slowly empty the contents into the sewer receptacle. Once the cartridge is tipped over and draining, push the pressure valve button at the top to release the pressure, so all the contents empty faster.

Emptying Cassette Toilet


Do NOT push the pressure valve until after you start emptying the contents else you risk raw sewage spilling through the button sidewalls and onto your hand.

How do I know this?

I was the one who was wondering what that button was for and pressed it while it was right side up spilling nasty sewage onto my hand. Another moment to throw up.

So now that I've entirely disgusted you with my cautionary tales (there's still one more below) – doesn't it make you want to RV? It's such a small part of RVing so don't let this deter you. Remember when I said you would become intimate with #1 and #2 – I wasn't lying!

Okay – so now that the cartridge is empty, you rinse it with water then dump it again until the contents run clear.

Rinsing Cassette Toilet

Next, add about 2 ounces of the cartridge chemicals to the tank, then add about 2 to 4 ounces of water to the tank. Put the lid back on, slosh the chemicals and water around the cartridge, and then put the box back into the side of the campervan and shut the door.

Done Cassette Toilet Emptying

It's that simple. Well – if you do it right and don't do what I did in the beginning, but that's why you're here – to learn from my mistakes!

Pros & Cons of the Cassette Toilet


  • More freedom of choices to empty the tank which can reduce your costs of paying to dump if you can’t find a free dump station.
  • You can dump at traditional RV dump sites like state parks, RV parks, wastewater treatment plants, but now you can roll this small tank, like a suitcase, to a pit toilet, bathroom toilet in a house, and the rest areas off of the freeway.
  • Easy to clean by adding water and sloshing it around to clean the insides and then dumping into the appropriate receptacle.
  • No more dreaded poo pyramids! I never had this happen, but I've heard horror stories on it. Poo pyramids occur in black tanks when there isn't enough water and chemicals in the tank to break down the fecal matter, so the poo keeps rising. Gross right?
  • No “stinky slinky” sewer hoses to store so saves on storage space as well.
  • Super fast and easy to empty.
  • No longer need to flush the black tank or put the rinsing wand down the toilet to clean the tank. Instead just put some water in the cassette toilet, give it a shake and empty.


  • Condensation on the inside of the toilet lid. I haven’t figured this out yet, and fellow RVers have noticed the same on their cassette toilet. Some say it's when you're in areas with high humidity, but I'm not 100% sure just yet as it also seems to happen when I was in a dryer area too.
  • Need to empty more often because it holds 4.6 gallons compared to 23 gallons in my other RV. It's a con only because I was able to last three weeks in my other RV, but that said, it's not a deal breaker for me, and I seem to do just fine with finding places in that time frame.
  • Tank sensor only shows when full and not how full it is at each level as it rises. This is a real bummer because when it's full, you can't go to the bathroom at all in it and need to find a place to dump before you can use it again. I had made the mistake of using it when it was full which leads me into how NOT to dump the cassette toilet.

How NOT to Dump the Cassette Toilet

One morning, shortly after I purchased the Hymer Aktiv, I woke up and saw the cassette toilet was showing full. So I went ahead and used the toilet thinking that I would dump the cartridge and then I would flush what was in the toilet bowl.


I pulled the cartridge out and everything that was in the bowl, #1 AND #2, fell through the bottom of the toilet, onto part of the cartridge remaining in the cartridge bay, and the rest splashed inside of the cartridge bay.

I almost threw up multiple times cleaning that mess up. It was awful! Just awful! I've never had kids, so I don't know what it's like to clean up poo, but this was all over everything.

After I cleaned up the mess, I knew I just had to figure out how that happened. So on closer inspection, the blade at the bottom of the toilet is the same blade on the cartridge in the cartridge bay, so when you pull the cartridge box out, anything in the bowl will spill through because there is nothing below it to stop from emptying since the blade is attached to the cartridge.

There needs to be a big warning sign somewhere in the bathroom about this when you first purchase!

I learned my lesson, and that won't be happening again!

All-in-all, I love the cassette toilet and it's ease of use. It really works for me and my travel style. I'm still loving my Hymer too!

Have you ever used a cassette toilet? Are you trying to decide on getting a campervan or something larger? Leave me a comment below.


Sunday 16th of August 2020

Thank you very much for your detailed explanation and "practical experience" tips and tricks. Straight talk is important. This was VERY helpful. My wife and I are thinking about getting a Teardrop for traveling just as a backup while driving for resting, relaxing, maybe occasionally camping (esp. during what is now a complicated time in these coronavirus days.) NuCamp has just gone over to cassette-only toilets, and of course just says "here it is!" and nothing more. Thanks again. Now I understand what's involved. It will enable us to make a good decision going forward.

Fred geiger

Sunday 17th of May 2020

Hi . Thx for all ur info. We downsized from a 10 cab over camper to a Metris semi mini van. I did the conversion myself, ( side pull out bed, full kitchen w micro and 3 cu ft 120V. Fridge). One thing about it that we really like is having a toilet , even though it is a quite small van ( great to drive and 24 mpg -gas) I found a China marine toilet that sits on top of a 9gal holding tank. So no outside black water tank necessary. I just plumbed in a 1 1/2 inch pipe and shut off valve and have a flexible sewer hose to drain it. We rarely poop in it- emergencies only, mainly night time taking a leak. Even easier than a cassette to drain ( at least in my mind) and 9 gal capacity. It’s a Dometic 711 M28 if u are ever interested in checking it out. U do a great job in yr blog ! Hope to see more in the future and Happy Travels!

Jody Brogley

Wednesday 31st of July 2019

Thank you for sharing your knowledge! Where is holding tank. Is it the white shelf under the cassette with the door? First time...too full, boooo. I also don't have a cap for the orange plastic hose. Splash , ugh. The chemicals, what and where do you get it. My dealership is not an option for information! Thank you SO much!!

David King

Monday 22nd of October 2018

Thank you, Amber, for your reply about my thoughts on having a back-up cassette. I know the Hymer Activ gets hammered about having less than 5 gals. of black tank capacity, so I thought such a back-up could put a quick end to those criticisms and decrease the "range anxiety" for those who might push the limits. I know there's no exterior storage compartment for the Activ, but wonder if any space might be available on the underside to build something to hold a removable cassette. I will check it out the next time I can crawl under an Activ. They found room for the underside a/c unit (for the Loft edition) and they plan to find room for the WATT fuel cell, so it's a low-tech possibility.

No reply necessary. Thanks again.

David King

Saturday 29th of September 2018

Amber, I've thought it would be prudent to purchase a second cassette to have on hand. Since I would not be full-timing, dedicating some space for it seems like good insurance. What do you think?

Amber Baldwin

Saturday 20th of October 2018

I personally wouldn't because of the space it takes up. I seem to manage to always find a place to dump the cassette tank so it's been a non-issue for me. If you're boondocking for more than 5 days at a time and you aren't full-time then it might be fine to get the extra cassette.