Dometic CTW 4050 toilet pump replacement

You are a star!   Two very ordinary flat head screwdrivers worked ok as prying tools and the seat came off OK exposing the seal - remove 8 bolts and the top spray ring/pipe connection still ok , no leak.  Juggle and remove the ceramic bowl and lo and behold the elbow joint is fractured and signs of flush water dried out. !    Just like yours and perhaps many people.   I will now head off on the web to the supplier you suggested  for elbows and tube.      I haven't tried to take off the pipe clips - I am only used to jubilee clip stuff.  Any good way to remove  and what to put back with?

Lie you I am baffled why the elbow should break - its a softish plastic and I suspect just degraded. Perhaps there is slight pipe movement with cassette going in or out or even the bowls moving.  Clearly a long term and known Dometic problem. Pity they aren't honest about it.    

Brian

Brian - here are the pictures showing the installation of the Thetford.  The first one shows the additional surround - it must be a stock item because it's all bevelled etc, in the right places! Second one, self explanatory - and the third shows the slight gap between the carpet and the base of the Thetford - but who cares

PS - must get the weedkiller out on the drive!

The pump on my 2012 Elddis Avante has stopped working a couple of times - because we hadn’t used the van for a few months, the pump impeller had just dried out and got stuck.  Only found out when pushing the flush button and getting nothing but a slight click. With a sharp point, gently prised off the stick on pad with the push button on it which reveals the power connections attached, undo a couple of screws in the panel underneath and lift it up - attached are the connections to the pump, extract the pump and gently turn the impeller to free it, then reassemble. Pump work again!  Quieter than it used to be too.

Hi Brian

Getting the clips off or back on is the most difficult part of the job. I tried using ordinary pliers and point nose pliers but they weren't much good. I found that a pair of pincers worked by far the best, they don't slip off the clip. Because of the lack of room I didn't find it possible to use a jubilee clip instead of the spring clip except for where the pipe attaches to the anti-siphon valve. Unfortunately it is a case of gentle brute force to get the clips open enough to slide over the pipe. Good luck.

Richardandros - you did post some pictures on here, in an earlier post in this thread I did provide a link to it, HERE

And yes, we are having our toilet changed at ALV in Tebay at the end of September.  I also think that paulfrompontefract is having his done in September.  

When speaking to ALV, they told us that they have done "loads" of these, not surprised, given the problems we've had, and reading other people's tales of woe.

Well done InaD.  I couldn't find it!  Pleased to hear you are getting it sorted as well - I knew about Paul.  Sounds like Jon at ALV is going to be busy - but you're in good hands - he's very good.

Thanks to Greeninit - you are right of course. It is 12V not 24V. Senior moment !

For info and future reference to service the Dometic flush pump you do NOT need to remove the toilet the pump comes out through the control plate orifice

Just had to deal with a non working pump. Checked electrics and all ok so had to try to access pump. There was not enough room to access the pump from the top because of the plastic pipe coming off at right angles so it was down to removal using the method in previous posts. The two screws in the floor at the rear of the cassette cavity were rather stubborn and the heads were chewed a bit by the time we got them out so replaced them with slightly shorter screws when refitting. Got the toilet removed and accessed the pump by the bayonet type fitting beneath the switch. Connected to a 12v power supply and using a screw diver levered the blades to get it started. It ran fine so reversed polarity and ran in the other direction. As we had the filler tank removed, I took the opportunity to flush the tank. I think the pink additive had contributed to the pump seizing up.  We then commenced to refitting everything. Unfortunately whilst doing so had a slight accident and the pipe fitting at the top of the housing broke!! We got over it by gluing a smaller diameter pipe inside to make an effective join. Continued to refit everything and test. All good. I did wonder afterwards if reversing polarity before removing the pump may have freed it up and save the job of removing the toilet!  Hope this might help someone with the same issue.