If you hear running water sounds inside your refrigerator, it's likely due to one of the following reasons:
Water Dispenser: If your refrigerator is equipped with a water dispenser or an ice maker, the sound you hear might be the flow of water through the water line. When the ice maker refills or when you use the water dispenser, water may flow through the tubing, creating a running water sound.
Defrosting: Modern refrigerators often have a defrosting system that helps prevent frost buildup. During the defrost cycle, any accumulated ice on the evaporator coils is melted, and the water drains into a pan or tray at the bottom of the refrigerator. The running water sound might be the water dripping into this collection pan.
Clogged Drain Line: In some cases, the drain line that leads to the collection pan during the defrost cycle can become clogged with debris or ice. This can cause water to back up and create a gurgling or running water sound as it tries to find a way out.
Water Line Issues: If your refrigerator has a water dispenser or an ice maker, there could be an issue with the water supply line. A partially closed water valve or a kink in the water line can lead to irregular water flow, which might result in running water sounds.
Ice Cubes Falling: Sometimes, when ice cubes are ejected into the ice bin, they can create a sound that resembles running water.
Faulty Water Inlet Valve: If the water inlet valve that controls the water flow to the ice maker or water dispenser is malfunctioning, it may create unusual noises, including running water sounds.
Expansion and Contraction of Parts: Temperature fluctuations inside the refrigerator can cause parts to expand and contract. This could potentially lead to clicking or running water-like sounds.
To determine the exact cause and address the issue, you should investigate the source of the sound. Start by checking if you can identify the location of the sound, and try to correlate it with any specific actions like using the water dispenser or the ice maker. If you can't find a straightforward explanation, it might be best to contact a professional appliance repair service to diagnose and resolve the problem.