Simon
In order to know what to look for may be an understanding of the purifierpiping would help. The system is separated from the engine lubeoilsystem, only connected via the lube oiltanks. You have two pumps one for dirty and one for clean oil. There are two heaters, one for the "washingwater" and one for the dirty lubeoil. When the engines are running, the warm coolingwater from the exhaustmanifold is used and enter via the washingwater heater, in this case probably not to be used. When the engines are stopped, cold water from the seainlet is entering the heater and heated before added to the purifier. The dirty oil is taken from either the dirty oiltank, or stb and port engine lubeoil system tanks,entering the purifier lubeoil heater heated if needed and afterwards mixed with the warm washingwater from the waterheater and fed to the purifier. I have added colours to the systemsketch below. Red warm washingwater, blue cold washingwater, green dirty lubeoil and yellow clean lubeoil, the black is sludge. As I said I believe a lot of the stuff is intergrated in the purifier. We really need a picture of the actual purifier.
Tore