Defrost and drain your freeze dryer after every cycle. This is very important. Otherwise, the ice may become too thick and prevent the water vapor from being captured on the walls of the chamber. This could send excess water through the pump. This is not always the case for candy loads, but for regular food loads is a must.

Make sure to run the vacuum pump with the gas ballast valve open about one to four full turns. This will help cycle water vapor through the oil.

Make sure the pump is on the correct side of the machine. If it happens to get installed on the drain side the pump could ingest liquid water after the defrost cycle.

Check that there is no liquid water in the vacuum chamber during the cycle. This can boil off and the refrigeration will not keep up. If too much water vapor is created all at once, excess water vapor may be sent through the pump.

Make sure that the chamber and tray rack are cold if you are skipping the freeze cycle. Otherwise there may be some melting going on that can cause liquid water in the chamber.

Keep loads to about 8 pounds of food for a medium freeze dryer or about 16 pounds for a large freeze dryer when wet food is being dried. Larger quantities of wet food could cause excess water vapor and therefore excess water in the oil.

If excessive water in the pump continues to be a problem for your specific application, active oil water separator filters are available for purchase on our website.