The leak often is caused by calcium residue which prevents to complete sealing of the joker valve.

Do you apply regularly a decalcifier ( some say you should not use a household one , some say apply it once per month or after 100"cycles") .

In addition there is a special oil for the loo, which keeps the rubber parts flexible.

 

I am still using the original set after 3 years ( in total about 15 weeks of usage by 2 persons ).

 

I am using Yachticon Products which are available from my local chandler:

http://www.yachticon.de" rel="nofollow - www.yachticon.de

 

To keep all rubber parts flexible : WC Öl

To remove residues in the system:  Schlauchfrei ( imho you can take any household decalcifier )

 

Fair Winds

Also (or alternatively) I am eating black water backing from the holding tank. What causes this problem and how do I Stop it?

Thanks

Terry                                                                                                                                                                                         

The standard arrangement with the holding tank is that the outlet from the toilet enters the top of the holding tank. The outlet from the holding tank in at the bottom which is above the water line. The only other fitting in the holding tank is a air vent at the top of the tank which is vented on the boats side. There is no way you can go straight from the toilet over board without changing the piping arrangement. You can of course just leave the sullage tank valve open and the effluent will go from the toilet into the top of the tank and straight out the valve at the bottom. If you make sure you pump a lot of water through the toilet after each use the effluent should get flushed out of the tank. 

The black water backing up into the toilet (blowback) after use is most likely caused by the joker valve not sealing properly. This is normally caused by a build up of a calcium like deposit on the valve which causes it to let effluent back through the valve. The replacement of the joker valve is not too difficult but is made easier if you have a "wet vacuum cleaner" that you can use to suck out the offending effluent before you dismantle the pump and valve to get at the joker valve. The pipe which goes from the toilet to the top of the holding tanks is about 38mm ID and about 2 meters long. So this pipe holds a fair bit of liquid and exerts a bit of head pressure on the joker valve. It is the liquid in this pipe which leaks back into the toilet. 

We replace the joker valves on our toilets once a year. We liveaboard our boat all year so the toilets get a lot of use. You can reduce the calcium build up by using a chemical to dissolve the build up - some people use vinegar and leave it in the toilet, pump and pipework for say 24 hours before using the toilet again. Others use "descaling" products available from hardware stores. When you replace the joker valve make sure you clean out the pipe where the valve fits into because it will have a build up as well. If you don't clean out at least the first say 75mm of the pipe you may find the joker valve does not sit correctly. After fitting a new joker valve and cleaning out the pipe and other components some people use the "toilet oil" product listed in another post above. Other people just tip some cheap olive oil down the toilet once a week or so. The olive oil seems to make a difference and may slow down the calcium build up.

If you pump a lot of water through the toilet after use you will find even when you do get "blowback" it will mainly be just salt water because all the effluent was pumped into the sullage tank and can't then run back into the toilet bowl. 

Rather than buy the toilet service "kit" I normally buy just the joker valve because the kit costs about E40 whilst the valve costs about E8. The other parts in the kit do not need to be replaced as often as the joker valve.When it gets to needing to replace the whole pump or base it is probably better to replace the whole toilet because they only cost about E130 for a complete toilet.  

This season we have started using the inline Yachticon Purytec  Head Treatment System which is simply a slow dose bottle fitted into the salt water supply line to the toilet just before the pump. According to the info on the bottle this product "cleans and deodorizes the bowl and lines and helps breakdown solid waste material with every flush". Time will tell if it does all it states but it does leave a nice smell in the toilet with each use.

I hope some of the above helps.

  

Like Waynes says it's the JOKER valve that need cleaning/replacing.

But If you buy a new pump or toilet you should go for Jabsco Twist n' Lock, which should prevent blowback:

http://www.jabscoshop.com/files/MAN%20TWIST%20N%20LOCK%20toilets%20doc632.pdf" rel="nofollow - https://www.jabscoshop.com/files/MAN%20TWIST%20N%20LOCK%20toilets%20doc632.pdf

I have not tried the "black sticker pump" with twist n' lock yet.

But I would try this before going a electric...

Again many thanks for your help in resolving this tricky problem.

Regards

Terry

I think the " holding tank pump" is an option and possibly a macerator pump but I am sure you don't have the pump fitted. We have the same switch but no pump.I think you will find all the Hanse sullage tanks are emptied to the sea by gravity which is not a bad design.

If your joker valve is badly choked up with calcium like deposits it may be too far gone to use the cleaners. These cleaners will keep the calcium at bay but may not completely clean the joker and completely fix your existing problem. Try the cleaners but I would replace the joker valve particularly if it has not been replaced before. 

Don't forget the rubber gloves when you do the job!

Again many thanks. I. was afraid it was just my ignorance of the boat that I couldn't find the pump!!!!!

Regards

Terry