Toilet Flush

Since we have had the Rienza (6.5 years) the toilet flush been intermittently unreliable.
So far I have changed the switch twice twice, changed the pump because the tank was thick with black gunk and repaired the wiring several times.
This time the switch was playing up going from not working to sticking on and keeping the pump running. I took the switch out to try freeing it off and spraying it with contact cleaner. The problem went to not working at all. The wiring at the joint in the feed wire had broken again. Despite me sealing it with heat shrink the connectors and wiring were corroded.
I have had dealings with vehicle wiring in the past and it’s asking for trouble having the wiring connections in water as they are on the Thetford flush system. I will try and re route the wiring so the connectors are above the water level but having the flush button right under the shower isn’t going to help. 
New switch ordered and we will see how long this lasts. 

Something is reminding me of a microswitch in the cavity where the cassette goes to prevent the pump operating when the cassette is out?
Worth a poke around in there, others will know I'm sure....

The problem has always been the connections within the flush tank Ian. There is probably some magic water proof connectors but I think re routing  above the water level as I said will be a start. 
The age of the wiring is always going to be against me but I am sure I can improve things. We used to have problems like this with vehicles that had cheap wiring looms and connectors that rotted away when I was doing breakdown work. You couldn’t solder connections so we had to rely on crimp connectors. 
Slightly annoyingly our N Reg Duetto never had this problem but the fuse in the main panel had to cleaned occasionally to get a good connection. I suppose I should be happy to be be able to sort the lesser technical problems rather than the issues the modern builds throw up.

Could you replace it with a manual flush?
The first 'van we used had a manual pump to flush the toilet. Never any problems. Our current van has a later Thetford toilet with electric pump. The pump seized frequently and had to be replaced. The switch assembly has been replaced too. It's an easy job to revert it back to a manual pump and I've vowed to do this the next time it goes wrong (needless to say, since I made that decision it has worked perfectly!).

Whilst I was sat on the toilet repairing this problem last time I actually thought about reverting back to a manual flush but thought it was a different system. As I said before our ratty old Duetto didnt have this problem and that was electric flush.
I will do some sussing and boggling about ready for next time it plays up.

Our van is a similar vintage to yours, so the Thetford is probably the same model (C200 if I recall). The electric flush seems to be an upgrade to the original manual system, replacing the old hand pump with the button, but I think the later technology was designed to fit exactly the same opening in the water tank as the original pump, which makes reverting a fairly simple operation. I'm sure I've seen info on the web about people doing just that - there may be something relevant hidden away on this forum!

I had a look on Jacksons web site regarding the pump. There is a video showing how to fit the manual pump. As you said it looks a direct replacement.
Adding up the cost of a replacement switch and a pump I am going to give this a try next time. 
All this agro with wet electics reminds me of a builder that used to call us out to his Transit. The indicator fuse used to blow when it rained. One of his rear lights was cracked and filled the indicator with water. No matter how often we told him to get a new light unit the only cure was when he eventually scraped the van. 

Had same issue on my 09 reg Nuevo.

My 15 reg Nuevo was ok

My 21 Reg Broadway has no seperate tank for flush, uses main tank. Is that progress or saving a few quid in build?

Richard G wrote:Had same issue on my 09 reg Nuevo.

My 15 reg Nuevo was ok

My 21 Reg Broadway has no seperate tank for flush, uses main tank. Is that progress or saving a few quid in build?

My 2001 Hymer took its flush from the main tank and when I swapped it for the  Lancashire I bemoaned the separate flush tank. Now I prefer it - but because I have changed from blue in the cassette to bio Persil liquid in the flush tank. On our last long trip I did get some black bits coming in the flush but once we were home jetted the inside of the tank as much as possible with a garden hose and rinsed it well until they all cleared. That's the first time I've had a problem but I've never used pink flush aid. Bio Persil gives us a much cleaner bowl and an easier empty. It seems more efficient at dissolving the Andrex.

The new switch arrived  on Saturday  but the post person put it in next doors post box. Thanks Royal Mail , next door should have been away but only got as far as getting there motorhome out of storage on Saturday before there trip was cancelled. If they had not cancelled there trip I would have been in trouble. We were here all day Saturday and there was no note through our door to say were it was.
Our normal postman is very good with parcels so I assume it was  as a different person. I will challenge them this morning.

To bring this to a close the switch is fitted. I tried to move the wire joints out of the water but it just cant happen. There isnt enough room for the wires to tuck up above the water level.  I have put heat shrink on the joints and insulating tape as well. I know heat shrink is supposed to be waterproof but it didnt keep the water out last time. Maybe its just cheap heat shrink but I used the bit that came with the switch and its done  what its supposed to do, shrink.
Another motorhome crisis averted for now. Management can flush the loo without using the shower head again.

Glad it's sorted, at least for now. Just reading about the possibility of retro fitting a manual flush. Although I've never had a problem (so far) with my electric flush, it would've stopped an event when we joined our grandsons who were camping with parents a few weeks ago. I thought nothing of it when one of the kids came in to use our toilet. However when I came to use it a while later, the previously empty cassette was full and the brimmed flush tank empty.. Turns out said grandson used the toilet like a domestic one, he thought the flush would stop automatically and kept his finger on the button till no more water came out....
Al.