Not sure what linkage you mean when you say the linkage jams but it sounds as though you need to get that fixed because if water keeps running down the pan then the other symtom you will be gettting is that the saniflo comes on regularly by itself, this will be putting extra work on the unit and will void your warranty and cause your saniflo to burn out sooner than later. As for the Syphoning, I assume the saniflo is on a floor above the ground floor and the outlet pipe from the saniflo go down not up, you simply need to put a air brake valve on the highest point of the outlet pipe to brake the syphonig when it starts, that is normally a really easy job providing you have good access to the pipe
David, April 2011