it just beeps three times and flashes the add water light, but the tank is full. won't start.

Diagnosis

The three beeps accompanied by a flashing "Add Water" light—despite a full reservoir—indicate a failure in the water level detection circuit. This specific Sweetcrispy model utilizes a magnetic float switch: a small, white plastic cylinder that floats on the water's surface. When the water level is sufficient, the float rises, triggering a reed switch that tells the control board it is safe to begin the freezing cycle. When the light flashes while the tank is full, it means the float is physically stuck at the bottom of the tank or the magnetic coupling has become misaligned. This is often caused by mineral buildup (calcium/lime) from hard water, which creates a frictional "crust" around the float's shaft, pinning it down. In some cases, a small piece of debris or a bubble of air trapped under the float prevents it from rising to the trigger point. Because the sensor reports "empty," the machine enters a safety lockout mode to prevent the pump from running dry and burning out.

How to Fix It

To resolve the sensor lockout and restart the ice-making cycle, follow these precise steps:

1. Unplug the unit from the wall outlet to ensure the control board resets and to prevent accidental pump activation during the process.
2. Remove the ice basket and the scoop to clear the workspace.
3. Gently tilt the entire machine 15 to 20 degrees to the left and right. This creates a wave action in the reservoir that can dislodge a stuck float from the side wall.
4. Using a clean plastic straw or a cotton swab, reach into the water reservoir and gently nudge the white plastic float cylinder upward. If you feel resistance, the float is likely scaled over with minerals.
5. Drain the reservoir completely by removing the rubber drain plug located at the bottom of the machine. Let the unit drain for 2-3 minutes.
6. Fill the reservoir with warm (not boiling) distilled water. The warmth helps dissolve mineral deposits that may be gripping the float.
7. While the water is filling, manually lift the float up and down several times with the straw to ensure it moves freely through its entire range of motion.
8. Plug the unit back in and press the "Start/Reset" button. The beeping should cease, and the "Add Water" light should turn off as the float reaches the trigger height.

If That Didn't Work

• Perform a Deep Descaling Cycle: If the float is still sticking, mix a solution of 50% white vinegar and 50% warm water. Fill the reservoir and let it sit for 30 minutes without running the machine. This dissolves the calcium carbonate buildup around the float shaft. After soaking, drain the unit and rinse twice with fresh water.
• Check for Air Lock: Sometimes an air bubble forms around the sensor. Unplug the unit and tip it completely upside down for 10 seconds, then right it again and refill. This forces air pockets out of the sensor housing.
• Inspect for Mechanical Obstructions: Use a flashlight to look at the bottom of the tank. Ensure no small pieces of plastic packaging or debris from the initial unboxing have fallen into the reservoir and wedged themselves beneath the float.
• Hard Reset the Control Board: Unplug the machine and leave it disconnected for at least 30 minutes. This clears the volatile memory of the logic board, which can sometimes "hang" on an error state even after the physical condition (water level) has been corrected.

Heads Up

• Use Distilled Water: To prevent the float from sticking in the future, use distilled or filtered water. Tap water contains minerals that create the "scale" that pins the float switch down.
• Avoid Overfilling: Do not fill the water past the "MAX" line. Overfilling can occasionally cause the float to wedge against the top of the sensor housing, causing an erratic reading.
• Weekly Cleaning: Once a week, wipe the interior of the reservoir with a damp cloth to remove biofilm or slime that can increase friction on the float's movement.
• Power Stability: Always plug the unit directly into a wall outlet rather than a thin extension cord. Voltage drops can sometimes cause the sensor logic to glitch, triggering false "Add Water" alerts.