Cassette Toilets - Pros and Cons

[jon]

I've had my cassette toilet for a couple years now and I'm kind of getting tired for taking the cassette in and dumping after every trip. Currently my van is not really a RV. It's more a multi purpose traveling/camping van without a water system. My gray water tank is a 5 gallon Jerry so my cassette toilet works very well.

I'm thinking about purchasing a real class B RV, so I'm wondering if it would be easier to stop at a dump station on the way home since I would need to dump the gray water anyway.

What does everyone else think?

Thanks,
Jon

[GeorgeRa]

I had both and currently have cassette:

Cassette pluses:
1. Great for shorter trips, for extended I just got a second cassette.
2. Possible to park RV in house garage, with cassette clean no odor (important for us).
3. Possible to dump in more places.
4. No hose to clean.
5. Great for starting conversation: so how do you like this sh…ty idea?

Black tank plusses:
1. Higher volume = lower frequency of dumping.
2. No need to handle 50 lb. full cassette even with wheels.
3. Usually better roof venting to control the odor.

For our use cassette is perfect, but good macerator pump drain would be good except odor in the working garage.

[jon]

Originally Posted by GeorgeRa

I had both and currently have cassette:

Cassette pluses:
2. Possible to park RV in house garage, with cassette clean no odor (important for us).

For our use cassette is perfect, but good macerator pump drain would be good except odor in the working garage.

I've got our retirement house plan drawn up and it includes a high garage bay for the retirement class b......What is this garage odor problem. Currently I wash and rinse with bleach after every trip. Wouldn't a small black tank similar to the Travato 59G be nearly as easy to rinse out?

I followed your RV build on the Sprinter forum. It's beautiful but I don't have the skills nor patience for a build like that. So, I've narrowed it down to a Travoto or Aktiv.

Thanks,
Jon

[avanti]

I am going to report on my recent experience with cassette toilets in my Iceland Trip thread, whenever I get back to that project. Here's my quick preview:

Although cassettes have some merit, for me the fatal flaw is that the system is not completely sealed. Ergo, they inevitably smell, at least somewhat. A properly functioning plumbed system has no path for gas leakage and will not smell at all (those who disagree with this have defective systems). The nature of cassette toilets makes this impossible. Maybe if our system had the optional electric exhaust fan feature, I might have felt differently, but even though we used the provided chemicals (we use and need none at all in our tank-based system), the constant subtle odor makes a cassette system a non-starter for us.

If I parked in a garage, I would rig up a vent hose to outdoors and slip it over the stack vent during storage.

[jon]

Originally Posted by avanti

I am going to report on my recent experience with cassette toilets in my Iceland Trip thread, whenever I get back to that project. Here's my quick preview:

Although cassettes have some merit, for me the fatal flaw is that the system is not completely sealed. Ergo, they inevitably smell, at least somewhat. A properly functioning plumbed system has no path for gas leakage and will not smell at all (those who disagree with this have defective systems). The nature of cassette toilets makes this impossible. Maybe if our system had the optional electric exhaust fan feature, I might have felt differently, but even though we used the provided chemicals (we use and need none at all in our tank-based system), the constant subtle odor makes a cassette system a non-starter for us.

If I parked in a garage, I would rig up a vent hose to outdoors and slip it over the stack vent during storage.

I rented a campervan before I bought my sprinter and it had an unvented cassette. I know the smell so I installed a SOG vent system in mine. When the flapper is open a small fan sucks air through a filter and out the bottom. it works like a charm.
SOG Toilet Kits, SOG Systems - Sog toilet kits for motorhomes and caravans. Eco Friendly no Chemicals

[Ron J. Moore]

Really glad this discussions came up...wondered the pros and cons of both systems. Ron

[GeorgeRa]

It is a matter of time required to clean a black tank versus a cassette. To get clean rinse water coming out from a black tank it was taking me 3 rinses with rinse sprinkler system built in, minimum 30 min. of wet work or longer if solids were too sticky. When going for a couple or three days this cleaning task was a driving force for us no to use the toilet. From my boating experience I never allowed to leave uncleaned black tank for storage. The garage storage added to a strong desire to keeping my van pristine clean.

With cassette it is simple and fast - drain, water fill, shake, drain repeat and done.

I agree with Avanti that black tanks installation tend to have a better passive roof venting system, but cassette can have one as well. I am in the midst of adding a low draw vent system by Lil-Stanker to keep negative pressure during opening even though we never had any odor problems. My Thetford 402C cassette toilet has spring loaded vent valve on the bottom of the cassette which automatically opens up during insertion of the cassette. The Lil-Stanker will connect to this vent pushing exhaust to the driver side. If I had my toilette in a different place I would simply connect this vent to a roof vent and there would be no difference to a black tank venting. Besides the vent the cassette upper opening blade valve is sealed if not used, so the system is as sealed as my black toilet was.

[avanti]

Originally Posted by GeorgeRa

If I had my toilette in a different place I would simply connect this vent to a roof vent and there would be no difference to a black tank venting. Besides the vent the cassette upper opening blade valve is sealed if not used, so the system is as sealed as my black toilet was.

I don't really agree with this. A black-tank system can be totally sealed end-to-end via glued or threaded pipe. In the best case, a cassette requires a pressure-sealed gasket, so the tank can be removed. I believe that that seal is the achilles heel, when it comes to smell. I'm sure it is fine when in perfect condition, but...

I admit that my experience is limited, so I don't mean to overstate my case. But if I were to ever consider a cassette, I would certainly include active ventilation and the power budget to run it all the time.

[Doneworking]

First, let me say I have absolutely no knowledge of or experience with a cassette toilet.

Second, let me say that I have stored two Roadtreks for almost fifteen years in a heated and air conditioned garage attached to our home and have NEVER had an issue with odor. Never.

As others have said, if you got an odor with your black tank indoors, you need to check your plumbing.

Paul

[BBQ]

.

I cringe every time someone says "cassette toilet is popular in Europe".

Well, they have no choice.

[GeorgeRa]

Originally Posted by avanti

I don't really agree with this. A black-tank system can be totally sealed end-to-end via glued or threaded pipe. In the best case, a cassette requires a pressure-sealed gasket, so the tank can be removed. I believe that that seal is the achilles heel, when it comes to smell. I'm sure it is fine when in perfect condition, but...

I admit that my experience is limited, so I don't mean to overstate my case. But if I were to ever consider a cassette, I would certainly include active ventilation and the power budget to run it all the time.

My experience with cassette is based on about 20-25 dumps, mostly into bathroom toilettes but a few times into RV dumps.

I counted the number of rubber seals on my 402C cassette toilet:
Cassette – main vent, main entry blade valve seal, discharge vent, discharge nozzle rotating seal, cap.
Toilette – to cassette seal.

I had one problem with toilette <> cassette seal due to incomplete insertion, since then no problem, I checked the key seals state by adding water to the bowl and see if its level holds. So yes, there are more seals than in a black tank toilet but I had no problem with them. However, I did have a problem with the black toilet bowl seal and it was a pain to replace.

The key potential problem is with the cassette blade valve, it can get messy if contaminated by solids, so we err on the safe side by opening the blade before using the toilet. Black tank toilette has the same seal but repercussion is minimal as compared to cassette which can spill its content while you carrying it to the dump.

Having both types, I must say they both are painful at different points of #1 and #2 management process and not much technology progress visible in the past decades or on the horizon. As we heading to the 48VDC we still going to have unpleasant dumps, cassette or black tank. We can fill jet fighters in the air but can drive over the discharge station and perform a dump without leaving the driver seat even with the 48VDC on board.

An absolute ideal scenario would be to use human #2 discharges for fuel cells, and processed #1 to wash the dishes.

[GeorgeRa]

Originally Posted by Doneworking

……………………..
Second, let me say that I have stored two Roadtreks for almost fifteen years in a heated and air conditioned garage attached to our home and have NEVER had an issue with odor. Never.
As others have said, if you got an odor with your black tank indoors, you need to check your plumbing.
Paul

My experience differs, I had the Bigfoot camper and the trailer stored in the not heated garage at different points of time, both reeked, the trailer was acceptable and variable but the camper was persistently bad, as far as my checking plumbing was OK and never leaked. I never figured out why.

[jon]

A BIG advantage is that cassettes don't have plumbing.

On the other hand when I built my last house the inspector asked me to add a sewer clean out just outside the garage which I did. Then I just couldn't help thinking it was like having my own RV dump station. Maybe next house I can strategically place my driveway clean out. At least it would be easy to flush the plumbing whenever needed.

[booster]

Our Roadtrek with macerator is stored in my workshop, which I am in a lot, and no smells. The only odor I ever find, and I have a sensitive nose is when we open the side storage where the macerator hose is stored. It is a sealed pod, so any tiny amount is noticeable when you first open the door, but it is quickly gone. I have heard from others with gravity systems that you can get very bad odors in a garage if you don't get the slinky completely clean, every time, and you don't have a well sealed storage tube.

[Saldar]

Originally Posted by jon

On the other hand when I built my last house the inspector asked me to add a sewer clean out just outside the garage which I did. Then I just couldn't help thinking it was like having my own RV dump station. Maybe next house I can strategically place my driveway clean out. At least it would be easy to flush the plumbing whenever needed.

You can use a 120V garbage disposal to pump waste a long way. Our "pee shooter" sends it 60 ft into our septic clean out (~2 ft elevation) in a garden hose. Other folks shoot even further. It's great to have the option to dump at home and not worry about finding a spot on the last leg of a trip, or giving up use of the toilet.

[Davydd]

I now park in a heated garage and I have not noticed any odors from black tank venting. However, my garage is high volume to disperse any odors being 18' x 45' x about 16' high.

Much higher volume of a black tank is a major plus. Ours is 18 gallons which last about 4-5 times longer than a cassette. You have to visit a dump station anyway to dump your grey water. Time to deal with disposal is a major plus as well. The enclosed odorless macerator system takes about 5 minutes to dump both tanks. We average anywhere from 9-12 days between dumps with a 26 gallon grey tank coupled with the 18 gallon black. We mostly dump at opportunity before total capacity is reached to anticipate boondocking where no dump facilities are available.

[BBQ]

Originally Posted by GeorgeRa

...

An absolute ideal scenario would be to use human #2 discharges for fuel cells, and processed #1 to wash the dishes.

[BBQ]

.

I am surprised that in 2017 we still have not come up with a robotic dumping station.

[tgregg]

Originally Posted by GeorgeRa

My experience with cassette is based on about 20-25 dumps, mostly into bathroom toilettes but a few times into RV dumps.

George,

My experience with a Thetford 402 cassette toilet ( not a porti potty ) is based on 13 years, 2 RVs and over 600 dumps.

The biggest plus is not being tied to dumping at an RV dump station. They are messy and in the morning when we want to leave there is usually a long waiting in line.

The campground toilets, whether they are flush toilets, pit toilets or outhouses, are always within walking distance of our site.

Many of the national parks and national monuments have special areas in the bath houses for dumping portable toilets.

We dump almost every day because it's so quick and convenient. With only a days use the cassette is also very light and easy to handle.

After dumping we usually drain the gray water into the cassette, use it to rinse the cassette and then dump that as well.

We've never had a problem with odor.

The second biggest plus with the Thetford 402 is it is sealed against the shower walls on 3 sides as well along the shower pan. This means no shower water, soap scum, dirt etc. can get behind or under the toilet and makes keeping the shower clean much easier.

My wife and I wouldn't have any other toilet system in our RV.

Tom

PS

A little olive oil on the blade seal once or twice a year keeps it in new condition.

[GeorgeRa]

Originally Posted by tgregg

George,
My experience with a Thetford 402 cassette toilet ( not a porti potty ) is based on 13 years, 2 RVs and over 600 dumps.
The biggest plus is not being tied to dumping at an RV dump station. They are messy and in the morning when we want to leave there is usually a long waiting in line.
The campground toilets, whether they are flush toilets, pit toilets or outhouses, are always within walking distance of our site.
Many of the national parks and national monuments have special areas in the bath houses for dumping portable toilets.
We dump almost every day because it's so quick and convenient. With only a days use the cassette is also very light and easy to handle.
After dumping we usually drain the gray water into the cassette, use it to rinse the cassette and then dump that as well.
We've never had a problem with odor.
The second biggest plus with the Thetford 402 is it is sealed against the shower walls on 3 sides as well along the shower pan. This means no shower water, soap scum, dirt etc. can get behind or under the toilet and makes keeping the shower clean much easier.
My wife and I wouldn't have any other toilet system in our RV.
Tom
PS
A little olive oil on the blade seal once or twice a year keeps it in new condition.

Impressive statistics.

I got a surprised look once, coming back from Arizona we stopped at a large RV place next to a highway, our Sprinter was very tiny among fifth wheelers and buses. A lady cleaning bathroom wondered, a bomb?, no, just processed burgers.