Toilet Flush Problems.

[pensioner]

My 2014 Lunar Cosmos 352 is fitted with a DOMETIC CTW 4050 toilet.

On a recent trip away the RED cassette full light came on and of course there is no flush.

I went out and removed the cassette but it was actually nearly empty so replaced it. The light was initially still on but went out within an hour and I had flush.

This happened twice more and then the light stayed on.

I've contacted Dometic and had an initial acknowledgement but as yet no advice.

Can anyone help with a cause and solution please.

 

[audiorob]

Presuming this is much the same in operation as earlier models. Is it possible that the internal flaot mechanism is stuck or held near the top of it's travel rather than floating up on the waste? You should be able to assess this via the soil entry point.
Within the housing is there a visible small circuit board at the back that reacts with the magnet in the float. Worth giving that a spray of circuit board cleaner . Mine once constantly showed full and it was after I had replaced the cassette in heavy rain and transferred moisture from cassette to circuit.
Presumably you have manuals, but these can be viewed and downloaded from the manufacturers site if you google the toilet description. I think you should also be able to access 'exploded' diagrams and consequent list of spare parts.
Good luck!

 

[pensioner]

Thanks Audoirob, I checked the float system and it's free and the mechanism it connects to moves as well.
I'll check the circuit board next, I think I have cleaner, if not I'll soon get some.
The manual isn't of any help at all, it only mentions 3 faults none of which apply.

 

[pensioner]

Latest update, had a chat with the guy from Dometic and he thought it may be a sticking magnetic switch.
I went into the van this morning and the light has gone OUT and I have flush, so I'm hoping it was damp in the switch system on top.
Was going to Maplins to get some spray, only to be advised by her indoors that it's closed.! I'll ask around for other likely outlets.
Thanks again for your help.

 

[SirRogerFFS]

Whatever you do DO NOT use WD 40 on it. you can get a WD 40 contact/ switch cleaner that is very good
Sir Roger

 

[pensioner]

Yes thanks SirRoger, I try to avoid WD40, I do use GT85 for lubrication, but I've bought some proper stuff which is due to arrive tomoro.

 

[SirRogerFFS]

we have had problems for ages with the flush on our van.It all started with the micro switch under the flush cassette housing then it was another circuit board under the flush button. The van is now 10 years old and several circuit boards later I have done away with the switch in the cassette and the circuit board in the flush tank and fitted a toggle switch no more problems .
Sr Roger .

 

[pensioner]

Nice one SirRoger, you must show me how

 

[camel]

Can't understand why the toilet needs a circuilboard what's wrong with a on off switch,

 

[SirRogerFFS]

Can't understand why the toilet needs a circuilboard what's wrong with a on off switch,

Camel ... The reason for the circuit board is quite simple is connected to switch in waste holding tank which tells you when the cassette is full. It is the worst thing Thetfords ever came up with If you read my previous thread you will see I have done away with circuit board and the switch in waste holding area and fitted a neat little toggle switch that sits nicely in the place where the circuit board would have been .
Sir Roger

 

[Underwood]

Dometic designed the CTW 4050 toilet (and subsequent models) with a control-panel with 4 informational displays as well as carrying the flush button.



Replacing the complete control-panel is far from cheap and I believe it may not be possible nowadays to obtain just the pcb .

https://www.inter-spares.co.uk/dome...100076500/control-panel-including-pcb-en.html

 

[camel]

My red light is on all the time I certainly don't need alight to tell me when my cassette is full I have eyes, so you removed the circuit board and then connected what to what please,

 

[camel]

Dometic designed the CTW 4050 toilet (and subsequent models) with a control-panel with 4 informational displays as well as carrying the flush button.

View attachment 97

Replacing the complete control-panel is far from cheap and I believe it may not be possible nowadays to obtain just the pcb .

https://www.inter-spares.co.uk/dome...100076500/control-panel-including-pcb-en.html

That circuitboard/ control is just more stuff that can go wrong,

 

[camel]

Dometic designed the CTW 4050 toilet (and subsequent models) with a control-panel with 4 informational displays as well as carrying the flush button.

View attachment 97

Replacing the complete control-panel is far from cheap and I believe it may not be possible nowadays to obtain just the pcb .

https://www.inter-spares.co.uk/dome...100076500/control-panel-including-pcb-en.html

£153.00 To replace that panel they must be joking I'll keep looking down the hole,

 

[pensioner]

Camel, you say your red light is on all the time,, so how do you flush as on mine the flush is inhibited when the light comes on.

 

[camel]

Camel, you say your red light is on all the time,, so how do you flush as on mine the flush is inhibited when the light comes on.

The red light is indicating that the cassette is full not to sure if it goes out when I take out the cassette to unload it,

 

[pensioner]

Yes I understand that, mine is the same but, with the red light on , mine will not flush,
How is it yours does.

 

[camel]

Yes I understand that, mine is the same but, with the red light on , mine will not flush,
How is it yours does.

Have you checked the fuse in the container that the cassette sits in right at the back have you checked all connections,

 

[Underwood]

I don’t know if this link will help

https://www.caravantalk.co.uk/community/topic/135676-dometic-toilet-light/

It is very apparent from the on-line complaints that the Dometic toilets have a reputation for warning light-related problems.