Freezers are very useful appliances, whether they take the form of stand-alone units or are part of refrigerator-freezer combos. In both cases, a freezer uses a series of components and controls to produce cold air that is capable of freezing water and keeping food at a set temperature. If you notice a puddle of water under your freezer, it can come from any number of sources.
If your freezer fails to run and the food inside melts, it may produce a large puddle on the floor below the unit. Failure can result from faulty wiring, a mechanical failure in the compressor or condenser, a bad thermostat or a lack of sufficient electrical power. Even though freezer doors seal tightly, they can't hold back the weight of water as frost and food products melt, allowing water to leak down the door seal and collect on the floor.
Freezers produce some water normally during each defrost cycle. This occurs when the freezer's defrost timer reaches its defrost cycle, which usually happens once or twice each day. The freezer coils heat up and allow any accumulated ice to melt. The melt-off and condensation collect in a drip pan that is mounted below the freezer. If you manually override the defrost timer to cause another defrost cycle before the water can evaporate, the pan may fill up and spill onto the floor.
Some freezers are equipped with water lines that feed automatic ice makers. These lines can be a source of leaks that result in puddles below the freezer. If the line itself ruptures, or if any of the gaskets that seal off the line's connection to your home's plumbing system or the freezer's ice mechanism fail, water will run onto the floor below the freezer.
A puddle of water under a freezer may come from a source entirely unrelated to the freezer itself. Most freezers and refrigerator-freezer combos sit low to the ground, meaning that spills in the kitchen can leave puddles that are difficult to notice and clean up. If your freezer is located in the basement, water from outside can leak in and pool up under the freezer, especially if the floor is sloped. Standing water can breed mold and damage your flooring over time. Check under the freezer during regular cleaning, both to determine that the freezer is functioning properly and to identify other problems in the area.