the ice size selector button doesn't seem to do anything, cubes are always the same small size.

Diagnosis

The perceived failure of the ice size selector on the Igloo Premium Self-Cleaning Countertop Ice Maker is typically not a mechanical failure of the button, but a misunderstanding of how the "S" (Small) and "L" (Large) settings operate. Unlike commercial machines that have different physical molds, this unit uses a single set of fixed-diameter aluminum freezing pins. The size selector does not change the width of the cube; it adjusts the duration of the freezing cycle before the ejector arm pushes the ice into the basket. When set to "Small," the machine triggers the harvest cycle earlier, resulting in a thinner, more fragile cube. When set to "Large," the compressor runs for a longer interval, allowing the ice to freeze deeper toward the center of the pin. Because the diameter remains constant, the difference is primarily in the thickness and density of the ice. If you are seeing "small" cubes on both settings, it is often because the ambient room temperature is too high or the water is too warm, preventing the "Large" setting from actually achieving a thicker freeze before the timer expires. To confirm if the button is working, you must observe the timing of the harvest cycle; the "Large" setting should take approximately 2-4 minutes longer per batch than the "Small" setting.

How to Fix It

To properly calibrate and verify the ice size functionality, follow these exact steps to eliminate environmental variables:

1. Empty the ice basket completely and discard any remaining cubes to ensure you are comparing fresh batches.
2. Fill the water reservoir to the "MAX" line using chilled, filtered water (approximately 40°F). Using room temperature water often masks the difference between the S and L settings.
3. Press the "S" (Small) button. Wait for the machine to complete one full cycle (approximately 6-10 minutes). Remove these cubes and place them in a separate bowl.
4. Press the "L" (Large) button. Now, wait for the full duration of the cycle. You will notice the machine spends more time in the "freezing" phase before the mechanical arm activates.
5. Compare the two batches side-by-side. The "Large" cubes will be noticeably denser and have a more filled-out center, whereas the "Small" cubes will appear more hollow or "shell-like."
6. If the cubes still look identical, power cycle the unit by unplugging it from the wall for 60 seconds to reset the internal control board, then repeat the process starting with the "L" setting.

If That Didn't Work

• Check for mineral buildup on the freezing pins. If you have hard water, calcium deposits can insulate the pins, preventing the ice from freezing deeply even on the "Large" setting. Run a cleaning cycle using a mixture of equal parts white vinegar and warm water to strip the scale from the aluminum surfaces.
• Inspect the ventilation gaps on the sides of the machine. If the unit is pushed against a wall or inside a tight cabinet, the condenser cannot shed heat efficiently. This causes the refrigerant to struggle, resulting in "Small" cubes regardless of the setting because the machine cannot reach the necessary temperature for a "Large" freeze. Ensure at least 6 inches of clearance on all sides.
• Verify the ambient room temperature. If the room is above 85°F, the machine will struggle to produce "Large" cubes. Try moving the unit to a cooler environment or a climate-controlled room to see if the size selector begins to show a visible difference.
• Test the button responsiveness by listening for the "beep" or observing the LED indicator. If the light does not toggle between S and L when pressed, the tactile switch on the PCB may be oxidized. In this case, a gentle spray of electronic contact cleaner into the button housing (while unplugged) may restore the connection.

Heads Up

• Avoid using distilled water; while it prevents scale, the lack of minerals can actually slow down the freezing process and affect the structural integrity of the "Large" cubes.
• Never force the ice out of the basket with a metal utensil, as this can bend the ejector pins and permanently ruin the ice shape or jam the size-selection mechanism.
• The "Self-Cleaning" function is essential for maintaining ice size consistency. Run this cycle once every two weeks to prevent biofilm and scale from insulating the freezing pins.
• Always keep the lid closed during the freezing process. Opening the lid lets cold air escape and warm air in, which often results in "Small" or malformed cubes even when the "Large" setting is active.