the 'add water' light is on but the tank is definitely full. it won't start cycling.

Diagnosis

The "Add Water" indicator on the NEWBULIG Portable Ice Maker is triggered by a magnetic float switch located at the bottom of the water reservoir. This float is a small, white plastic cylinder that rises and falls with the water level. When the water is low, the float drops, breaking the magnetic connection with the internal sensor and triggering the alert light. If the light remains on despite a full tank, the float has likely become physically jammed against the side wall of the reservoir or is stuck in the "down" position due to mineral buildup (limescale) or a small piece of debris. Another common cause is the formation of a vacuum or an air bubble trapped beneath the float, or in some cases, the float has become detached from its guide rail. Because the sensor relies on a precise magnetic alignment, even a few millimeters of deviation or a thin layer of calcium deposits can prevent the sensor from registering that the float has reached the "full" threshold. You can confirm this by looking at the float; if it is sitting at the bottom of the tank while the water is deep, the sensor is malfunctioning or obstructed.

How to Fix It

To resolve the sensor jam and reset the cycling process, follow these exact steps:

1. Power down the unit completely by pressing the "Power" button and then unplugging the power cord from the wall outlet to ensure no electrical current is running to the sensor.
2. Remove the ice basket to gain full access to the interior of the machine.
3. Locate the white plastic float bobber. It is typically positioned near the corner or center of the water reservoir floor.
4. Using a clean finger or a soft-bristled brush, gently push the float down and let it pop back up. Repeat this motion 5-10 times to break any mineral bonds or dislodge debris that may be pinning it down.
5. If the float feels "gritty" or resists movement, pour a mixture of warm water and white vinegar into the reservoir. Let it sit for 15 minutes to dissolve calcium deposits, then manually wiggle the float again.
6. Drain the reservoir completely, wipe the interior walls with a microfiber cloth to remove any slime or residue, and refill it with fresh, filtered water up to the "MAX" line.
7. Plug the unit back in and press the "Start" button. The "Add Water" light should now be extinguished, and the motor should engage to begin the 6-minute freeze cycle.

If That Didn't Work

• Perform a Hard Reset: Unplug the machine from the power source for a full 30 minutes. This allows the internal capacitors to discharge completely and can clear a "ghost" error state in the control board that keeps the light active even after the float is freed.
• Check for Float Misalignment: Use a flashlight to ensure the float hasn't popped off its vertical guide pin. If the float is floating freely without being attached to the pin, it cannot trigger the magnetic switch. You may need to carefully slide it back onto the pin using a pair of plastic tweezers.
• Test with Distilled Water: If you are using hard tap water, the sensor may be hypersensitive to mineral film. Drain the tank and fill it with distilled water. If the light disappears, the issue is mineral accumulation, and you should run a full cleaning cycle using a dedicated descaling solution.
• Inspect the Base Seal: Ensure the reservoir is seated perfectly flush against the machine base. If the unit is tilted or sitting on an uneven countertop, the float may be resting against the side wall at an angle, preventing it from rising vertically.

Heads Up

• Use Filtered Water: To prevent the float sensor from sticking in the future, always use filtered or distilled water. This prevents the buildup of calcium and magnesium (limescale) which is the primary cause of sensor failure.
• Weekly Cleaning: Use the "Auto-Cleaning" function once a week. This doesn't just clean the ice tray; it flushes the water lines and helps keep the float area clear of biofilm.
• Avoid Harsh Chemicals: Never use bleach or abrasive scouring pads inside the reservoir. This can scratch the plastic, creating "catch points" that make it easier for the float to get stuck.
• Avoid Overfilling: Do not fill the water beyond the "MAX" line. Overfilling can cause water to seep into the internal electronics housing, which may lead to permanent sensor failure or short-circuiting.