Cassette Toilet level indicator not working

stepheng

Just de-winterized my new to me 2022 320S. The level indicator on the cassette toilet is not working. Is there a way to test the sensor in the cassette? Does the trailer have to be level for this to work properly?

Yoshi_TAB

Hi, Is it not lighting up or is the level indicating wrong. 

Not sure if this can help, but in my 2021,  I had purple wire that was loose in a crimp (there were 4 wires in the crimp).   I found out the purple wire went to the cassette toilet in addition to the red power wire.    I don't know if the purple was for the sensor.  My issue was an intermittent fuse blowing.  I reconnected with a more secure wago connector.  Maybe something to look for.  The crimp was in the bundle behind the WFCO.

MuttonChops

In addition to checking the wiring you might be able to confirm Tank Float control arm is not jammed.

The 3 attached PDF files (pages of other manuals) include:
Troubleshooting and parts location information.

Good Luck

GregChris

The level indicator in our cassette has never worked. The red light comes on when it's full. 2021 320s bd

stepheng

@MuttonChops - does your level indicator work as the cassette tank fills?  Progressive green lights then red when full?

There are three LEDs on the left side as you face the toilet.  The bottom level light is green when I quickly press the flush button but not long enough to flush.  Filled it with water today and never saw any other lights turn on.  I may not have filled it completely, but I could see that it was getting close to full.  I would have expected the bottom and middle LEDs to come on to show it was filling up.

Does the top plate (#3 in tank parts) unscrew so the float arm can be inspected?

MuttonChops

stepheng said:
. . . - does your level indicator work as the cassette tank fills? 
. . . Does the top plate (#3 in tank parts) unscrew so the float arm can be inspected?

No idea, my rig does not have a cassette.
I just thought you might find the PDF files helpful to your investigation.

techietab

I admittedly have not read the documentation, but I assumed the LEDs aren't meant for indicating fullness of the cassette. The model that's in 320S's has an optional funnel-fill capability for an independent fresh water tank (not implemented by NuCamp), and I think that's what the indicators were intended for. They've never worked on my 2022 model.

Took a look at the owner's manual for the similar model currently on Thetford's website:

"Level indicator display: the red LED on the display lights up when the waste tank is full (C-402C and C-402X). When the flush knob is pressed briefly, the display shows the level in the waste tank and the level in the water tank"

So if I'm reading that correctly - expected behavior is a red light only is the cassette is full. The other LEDs are for the optional water tank.

stepheng

I'm going to do some testing today and will let you know the results.

Also, is there a drain in the compartment in case the cassette overflows?  Would be big mess in trailer.

Yoshi_TAB

Hi,

Are you talking about this opening  (first picture) inside the compartment?  If so, this is a vent.  It goes out to a vent at the bottom of the TAB (see second picture) .  It matches up with the vent on the bottom of the cassette (third picture..not very good).  If you push the vent on the bottom, it raises and lowers and open and closes a vent in the cassette , under the cap on the top of the cassette. (see picture 4 & 5).

scott14

On our 2022 320S, my experience has been that the LEDs to the left of the toilet function and indicate the level in the cassette. I do not believe there is a drain in the cassette compartment.

Yoshi_TAB

Hi,

In the manual that came with my toilet, it says those lights are for the waste (cassette) holding tank level indication , but also says "only one LED for the 402-C model.  The manual is for the 400 series toilets. 

The difference between the 402 and 403 L is the 402 C/X has an intergal water tank to provide water and the 403 L is connected to the RVs central water system.  So I'm assuming we have the 403.  

stepheng

When I removed the cassette yesterday, when de-winterizing the trailer, I noticed that this area was full of water. It had not overflowed, but was almost to the top. I don’t know where the water came from but it concerns me that it could collect water and there is no way for it to drain out. Maybe we should consider adding a drain to this area?

jbajor

My experience has been that the second LED comes on when cassette is almost full and 3rd LED comes on when you have about one flush left.

stepheng

@jbajor is correct. 
Here’s what I found out from my testing.

I filled the empty cassette with clean water, and after 17 L of water the middle light came on.

I then added one more liter for a total of 18 liters and the red light came on at the top of the display and stayed on. 

It appears to work and the bottom LED means the cassette is somewhere between empty and almost full. The middle LED means that the cassette is almost full and the top LED means the cassette IS full.

I also learned how to remove the top of the cassette with the blade assembly and the float. This should be done periodically to clean the assembly and better clean the cassette. you should also lubricate the blade seal and the top assembly seal whenever this is removed, I will post a PDF file later with photos, describing how this is done.