My Fisher & Paykel E450 fridge only unit seems to be draining out too much water. The drain capture container at the back of the unit fills up about once a week. Any help would be good.

A fridge must be transported upright or if not left idle for several hours in it's new home before switching on. Failing to do that can seriously reduce the life of the compressor as also failing to ensure it is adjusted level to a spirit level or plumb-line accuracy can similarly do so.

A frost free fridge can produce quite a lot of water depending on the usage, the contents and ambient humidity. The water in the capture container that is fitted directly to the top of the compressor should evaporate almost as soon as it is produced due to the heat generated by the compressor.

It is possible the fridge isn't producing abnormal amounts of water unless the door seal is faulty, the door is being left open for periods that are too long or hot food or very moist food is routinely being placed inside.
It is possible the water isn't evaporating fast enough because the compressor isn't getting hot enough - possibly because it isn't working hard enough or perhaps it is cycling too quickly. Perhaps it has lost some refrigerant...