it's making ice but the cubes are super thin and hollow, like little shells. what's wrong?

Diagnosis

The production of "shell" or hollow ice cubes in the Igloo ICEB26AQ is a classic symptom of an insufficient water fill cycle. In a healthy cycle, the pump pushes a specific volume of water into the freezing molds; if the volume is too low, the water doesn't fill the mold to the brim. Because the cooling pins freeze the water from the outside in, the small amount of water available freezes against the walls of the mold first, leaving a void in the center. This is typically caused by a restriction in the water flow path, most commonly mineral scale buildup (calcium and magnesium) within the internal pump or the intake filter. When the pump struggles to push water through a clogged filter, the water level in the tray never reaches the trigger point for the sensor to stop the pump, but the pump times out or fails to deliver the required volume before the freezing cycle begins. You can confirm this by watching the fill cycle: if you see the water barely trickling into the tray or if the pump sounds strained (a higher-pitched whine), you have a flow restriction.

How to Fix It

To restore full ice cube volume, you must clear the water delivery system and descale the internal components. Follow these steps precisely:

1. Unplug the unit from the wall outlet and remove the ice basket and the water reservoir to access the internal chassis.
2. Locate the water inlet port where the reservoir connects to the main unit. Inside this port is a small, cylindrical mesh screen filter. Use a pair of needle-nose pliers or a toothpick to gently extract this filter.
3. Submerge the filter in a solution of 50% white vinegar and 50% warm water for 30 minutes. Use a soft-bristled toothbrush to scrub the mesh, ensuring no white mineral flakes remain.
4. Prepare a descaling solution by mixing 1 cup of white vinegar with 2 cups of warm distilled water. Pour this directly into the reservoir.
5. Plug the unit in and run a "Clean" cycle if available, or manually trigger a fill cycle. Let the solution sit in the internal lines for 20 minutes before running the pump to flush the system.
6. Drain the reservoir completely, rinse it with fresh water, and refill it with filtered water.
7. Run three full cycles of ice production and discard the first two batches to ensure all vinegar residue is gone.

If That Didn't Work

• Check the Water Level Sensor: If the filter is clean but the cubes are still hollow, the water level sensor (the small probe in the freezing tray) may be coated in limescale. This "blinds" the sensor, causing it to tell the pump to stop prematurely. Use a cotton swab dipped in white vinegar to gently scrub the metallic probe until it is shiny and free of white deposits.
• Inspect the Pump Impeller: If the pump sounds weak, a small piece of debris or a mineral chunk may be lodged in the impeller. While the unit is unplugged, check the pump intake for any visible obstructions. If the pump is failing mechanically, you will need to replace the internal pump assembly (Part #ICEB-PUMP-01).
• Adjust Ambient Temperature: If the unit is placed in a room above 90°F (32°C) or directly in sunlight, the cooling pins may be overheating. This can cause the water to freeze unevenly or evaporate slightly during the fill process. Move the unit to a cool, ventilated area with at least 6 inches of clearance on all sides.
• Verify Water Hardness: If you are using hard tap water, the scale will return quickly. Switch to distilled or reverse osmosis water. If you use distilled water, add a tiny pinch of salt to the reservoir to ensure the water level sensor can still detect the liquid via conductivity.

Heads Up

• Never use caustic chemical descalers or bleach in the reservoir, as these can corrode the aluminum cooling pins and ruin the unit.
• Perform a vinegar rinse every 30 days if you live in a hard-water area to prevent the "hollow cube" phenomenon from returning.
• Always ensure the reservoir is seated perfectly flush against the intake port; a slight gap can introduce air bubbles into the line, leading to inconsistent fill levels.
• Avoid overfilling the ice basket; if the basket is too full, the sensor may trigger a "Full" signal prematurely, interrupting the cycle.