Dometic CTW 4050 toilet pump replacement

 Message for Dave Nicholson and / or Richardandros. Which Thetford toilet did you install as a replacement for the Dometic CTW 4050?  I might have to bite the bullet and change to Thetford.  Thanks in advance.

John

Yet another tale of woe with a Dometic toilet.  We've got our van booked in for the end of September to get the toilet swapped to a Thetford.  I don't know the model they will use, but in a previous thread richardandros posted a few photos of their Thetford replacement, LINK 

It's on one of the later pages; the thread makes for interesting reading I think.  We've been away last month, and all went well with ours, although the "full" light stayed on a few times after emptying it, but we can't have it all I suppose  Our problem (up to now anyway!) has been different in that we were unable to actually get the cassette out in the first place, but if you read through the linked thread, you'll be able to read all that, won't go into it again here.

Good luck!

Same problem, rinse leak into the compartment.  I removed toilet unit (CTW 4050), easy to check pipe fitting exiting from pump - no leaking, looks in perfect condition, but can only inspect bowl connection from inside with mirror and cant be sure of a defect or break etc.  Getting to that part looks like a complete disassembly of the unit. Is that so?   Any simple ways to do this.  Don't really want to replace whole unit (expensive) and can't find a Dometic Agent who can fully service.  In any case can not find CTW4050 in market place , only CTW 4110 - hopefully has same hatch and filler location holes.

Lateron , it was posted that could be replaced with Thetford,say 260 series which look the same but would hatch and filler holes in side of van be in exactly the same place?

Up t now using the several other forums, where no complete solution offered.

regards

Brian, Basildon Essex

Would you please advise exactly what model Thetford was the replacement.    Also was the filler hole in the side of the van in exactly the same place as the previous Dometic 4050, or was there no external filler - I think there are some models of the 4050 that don't have an external filler flush water - the external one that does is the CTW 4050

Photos won't upload - probably too big.

Brian

Brian - I think it is the Thetford C263 -CS.  The only 'problem' that you will have is that - as you rightly suspected - the filler holes don't line up - so it's not possible to use a Thetford model that requires an external filler for the flush tank. The 263CS has a dummy header tank so, to all intents and purposes, it looks almost identical to the Dometic from inside the van.  The only difference being that the curve around the base is slightly different, so if you have a fitted carpet around it, it doesn't quite follow the contour of the new toilet.  That said, unless it was pointed out to you, you would never notice.

The flush water, therefore has to come from another source - and in our case, in comes from the inboard tank - which supplies all our water for the van, anyway.  (Filled up automatically from the aquaroll).  I believe, however, that there is no reason why that flush water can't come directly from the aquaroll - just a question of putting the pipework in.

I was a bit sceptical, at first, about the water coming from the inboard tank and therefore not being able to put additive in - as I always had.  In the event, I actually prefer it - no additive isn't a problem - we use a spray bottle if required - and not having to think about filling the flush tank is one thing less to do!

All of this renders the existing filler cap on the outside of the van, redundant.  However, that again isn't a problem because the appearance of the van isn't altered and no one but you knows it's now just there for 'decoration'!! 

This little exercise cost me £650 for the dealer to carry it out - and they have done loads because of all the complaints they had received about Dometic toilets  - so they were well experienced at it.  Although the van was only five months old, it couldn't be done under warranty because it wasn't a 'like for like' replacement. That said, it was the best decision I made because that blasted Dometic toilet was spoiling what was an otherwise, near perfect, van.

Hi Brian

More of the flush water pipework can be fairly easily exposed for checking. Remove the seat with the tool which should have been provided with the Dometic handbook. This is pushed under the seat rim at the several points indicated with arrows moulded into the seat assembly. Once this is removed it exposes the flush ring. This can then be taken out by removing the screws, I think there are 8 of them. The ring can then be gently lifted and the pipe, the connection onto the flush ring and another elbow where the pipe comes through from the main body of the toilet can be examined. It was this elbow that had fractured on mine. There is plenty of slack in the pipe which is housed between the ceramic bowl and the outer plastic part of the bowl. Refitting is just a reverse of the foregoing. 

If it is the elbow that has fractured may I suggest using the company that I obtained both the correct pipework and elbow from - PVC Tube Online Ltd. The pipe is 16mm with a 10mm bore and the elbows 10mm. I bought more that I needed including three elbows for just over £10 including delivery.

Hope this helps.

Brian

I forgot to add that the above can be done with the toilet in-situ. If you need to replace the pipe or elbow I'm afraid it is probably a complete toilet removal as the pipework goes behind the header tank. See my earlier post about how I did it.

Thats very helpful.   I haven't got the 'tool' you mentioned so I will search for it in my record files etc or otherwise  apply my 'prying'  skills.

Next weeks job!

Brian

Thanks Richard , very helpful if I eventually change to the Thetford. Was the cassette outer door in the same place, - used the original? I dont mind the water filler door being surplus.

Did you 'tee' off the cold water pipe which runs adjacent to the toilet (in my case heading for the bathroom).   Presumably a length  of plastic  pipework and tap to squirt down the bowl when required or piped into and connected to the Thetford intake - did it need  an anti siphon valve or was that within the Thetford?

As you say its worth the money getting it sorted but down here caravan servicing people are completely full for months so a DIY approach is more likely for me.

Thanks

Brian

Brian

I did post some pictures on here of the installation (or it might have been Caravan Talk!).  Either way, I can't find them and I seem to have Deleted User them from my phone/computer.  I will take some more so that you can see the result.

The existing door is used but I think the Thetford cassette housing must be slightly larger than the Dometic because I have an additional surround around the aperture.  It looks very professional, though, and anyone looking at it would think it was the standard fit. It's difficult for me to ascertain how it is plumbed in because most of the pipework is in existing trunking - but there must be a "T" somewhere from the existing cold water feed to the bathroom and it just connects to the Thetford toilet - press the button on the top and it flushes!

Another advantage is that since the header tank is a dummy - there is no condensation / dampness to get to the switch / PCB which I know seems to cause quite a few problems for others.

I have pointed a few others in the direction of ALV at Tebay who are used to doing the work and I know that at least one person is getting it done there - but is having to wait until September.

Good luck!