The short answer
Start by checking the water level against the fountain's manual. Unplug it before handling the pump, then inspect its seating, removable intake parts and water channels. A dry or badly seated pump can sound different from normal flowing water. Stop using a unit with damaged wiring, leaks near electrical parts or a hot smell.
Identify which sound has changed
Listen from a short distance before touching anything. Is the sound a louder splash, a steady vibration against the bowl, or an irregular mechanical rattle? Water falling farther after the level drops can make splashing more noticeable. A pump touching the housing can transmit vibration through the fountain and the floor.
Make a note of when the sound began. Noise immediately after cleaning points you toward assembly and seating. Noise that builds gradually suggests checking the water level and accessible debris. These observations narrow the task without requiring you to open electrical components.
Check water level before changing parts
Use the marked operating range or the instructions supplied with your fountain. Refill with fresh water when it is low. Do not infer the correct level from the total advertised capacity, because the pump may need a particular depth to operate correctly. Never let the pump run dry as a test.
If the sound continues at the correct level, unplug the fountain with dry hands. Put out a clean water bowl so the investigation does not interrupt your cat's access to water. Leave the power adapter somewhere dry while you work.
Inspect the seating and assembly
Check that the pump sits in its intended position and that any suction feet, clips or mounting points are secure. Look for a tube that is only partly inserted, a tray that is sitting unevenly, or a cover resting against the pump. Refit removable parts in the order shown in the manual.
Place the fountain on a level surface. A wobbling base or contact with a cabinet can amplify sound. Do not wrap the pump in fabric or foam inside the water, and do not block vents or alter the electrical housing to make it quieter.
Clean the parts you are allowed to open
Hair or grit around an accessible intake can interfere with water movement. Follow our cat fountain cleaning routine, with special attention to the pump instructions for your model. If the manual permits removing the impeller cover, check that area gently and put it back correctly.
The Stream fountain and Ripple fountain use powered circulation, so pump access matters when comparing them with a gravity dispenser. A still bowl avoids pump noise but still needs regular washing.
Know when to stop troubleshooting
After careful cleaning and reassembly, refill and briefly observe normal operation. If unusual mechanical noise persists, ask the seller about the correct replacement pump. Match the actual model and power requirements; a plug that fits does not establish electrical compatibility.
Do not continue running a unit that leaks around power components, has a damaged cord or produces a hot smell. A backup bowl is the practical solution while you resolve the fault. Catit's fountain manual also distinguishes pump cleaning and water-level checks from running a pump dry.
