Final answer:
Water presence in a Freon refrigeration system can result in a frozen expansion valve which disrupts the refrigeration cycle.
Step-by-step explanation:
Any water present in the refrigeration side of a Freon refrigeration system can cause a frozen expansion valve. The water can freeze at the expansion valve due to the low temperatures encountered there, potentially blocking the flow of refrigerant and disrupting the operation of the refrigeration cycle. This happens because the liquid refrigerant is cooled through expansion at the expansion valve, which can drop to temperatures low enough to freeze any moisture that might have entered the system.