Today we sailed and motored a few miles north to Benicarlo which is a pretty marina. The heads ( toilets) have been back filling the whole trip and today was the day to tackle them. The problem is Javelin has an American toilet not the standard European ones but I did have an exploded parts diagram and a service kit. I diagnosed the problem as the joker valve, yes that is correct it is called the joker valve! The picture shows the old one after taking it out. This is on the waste exit and was completely furred up with calcium and C***. The pipe was also about a third of its diameter due to the same material. 4 hours later after lots of grunting and swearing the system is back together again and touch wood working well. I am on the beers now after a cleansing shower!
To make matters worse another English boat has moored alongside and the skipper/owner has delegated maintenance to a crew member. I obviously need an engineer for these troublesome tasks.