Small or hollow ice cubes are usually caused by low water supply, incorrect water level, high ambient temperature, or dirty condenser coils. Check and clean these components first before considering replacement.
Our editorial team compared specifications, buyer feedback and key decision factors to explain why ice makers produce small or hollow cubes and how to resolve them. If you've noticed your ice cubes looking smaller than usual or with a hollow center, you're not alone. This is a common complaint among ice maker owners, but the fix is often simple and doesn't require a service call.
Why Ice Makers Produce Small or Hollow Cubes
Several factors can cause incomplete ice formation. The most common is a low water supply to the ice maker. This can happen if the water line is kinked, the water filter is clogged, or the water inlet valve is failing. When the ice maker doesn't get enough water, it fills the mold only partially, resulting in small cubes. A hollow center often occurs when air gets trapped in the water line or the freezing process is too rapid, causing the outer shell to freeze before the center fills completely.
Temperature issues also play a role. If the freezer or ice maker compartment is too warm, the ice may freeze too slowly, allowing air bubbles to form. Conversely, if the temperature is too cold, the water may freeze before the mold is fully filled. The ideal freezer temperature for ice production is between 0 and 5 degrees Fahrenheit (-18 to -15 degrees Celsius). Dirty condenser coils can cause the compressor to overheat, reducing ice production efficiency and leading to smaller cubes.
For countertop and portable ice makers, low water in the reservoir or a dirty unit can cause similar problems. Mineral buildup from hard water can restrict water flow, and a dirty ice maker can harbor bacteria that affect ice quality. Additionally, some ice makers have a water level sensor that may malfunction, causing the unit to think the reservoir is full when it is not.
How to Fix Small or Hollow Ice Cubes
- Check the water supply. Ensure the water line is not kinked or pinched behind the refrigerator or under the sink. If you have a water filter, replace it if it's more than 6 months old. For countertop models, refill the water reservoir to the correct level and ensure the water pump is working. Also, inspect the water line for any visible cracks or leaks.
- Clean the condenser coils. Unplug the refrigerator or ice maker and locate the coils (usually at the back or bottom). Use a vacuum or coil brush to remove dust and debris. This improves heat exchange and helps the unit maintain proper temperature. For under-counter models, the coils may be behind a front grille; remove the grille and clean carefully.
- Adjust the freezer temperature. Set the freezer to between 0 and 5 degrees F. Use a thermometer to verify. If the temperature is too high, the ice maker may not freeze completely; if too low, it may freeze too fast. Allow 24 hours for the temperature to stabilize before checking ice quality.
- Clean the ice maker and water lines. Use a manufacturer-approved cleaner or a mixture of vinegar and water to remove mineral deposits. Run several cycles to flush out any residue. For countertop models, clean the reservoir and ice basket regularly. Pay special attention to the ice mold where water fills; mineral scale can build up there and reduce water volume.
- Inspect the water inlet valve. If water supply is adequate but cubes remain small, the valve may be failing. Listen for a humming sound when the ice maker calls for water. If you hear nothing or the valve is stuck, it may need replacement. You can also test the valve with a multimeter for continuity; if it fails, replace it.
- Check for air in the line. After installing a new filter or water line, air can get trapped. Run the ice maker for a few cycles to purge the air. You can also manually pour a small amount of water into the ice mold to help it fill completely. This is especially helpful for countertop models with a manual fill option.
Preventive Maintenance Tips
Regular maintenance can prevent many issues. Clean your ice maker every 6 months, replace water filters as recommended, and ensure proper ventilation around the unit. For countertop models, use filtered or distilled water to reduce mineral buildup. Also, check the water reservoir level frequently and refill as needed. If you notice a sudden change in ice quality, address it promptly to avoid more serious problems.
When to Replace Your Ice Maker
If you've tried all the above steps and the ice cubes are still small or hollow, the problem may be a faulty control module, a defective water inlet valve, or a failing compressor. For under-counter or built-in ice makers, professional repair can cost $150 to $300 or more. If your unit is more than 5 years old, replacement is often more economical. For countertop models, the cost of a new unit is often comparable to a repair. Check the current price on Amazon for a replacement that fits your needs.
Regular maintenance can prevent many issues. Clean your ice maker every 6 months, replace water filters as recommended, and ensure proper ventilation around the unit. By following these steps, you can enjoy full-sized, clear ice cubes for years to come.