You grab a glass, press the lever on your refrigerator door, and… crunch. Instead of solid, uniform ice cubes, your dispenser spits out tiny, fragile chips. Or worse, the dispenser motor grinds and hums, but nothing comes out at all because a giant, frozen “igloo” of broken ice has jammed the chute.
If you notice your ice maker making small (or hollow) ice, you are dealing with a very specific and frustrating problem: insufficient water volume.
Unlike an ice maker that stops working entirely, a machine making ice maker small cubes is trying to work. The motor is running, the cycle is turning, but the ice mold isn’t filling up all the way. This creates cubes that are stunted, or deceptive “ghost cubes” that freeze on the outside but remain empty (hollow) on the inside.
These ice maker hollow cubes are more than just a nuisance—they are the #1 cause of broken ice dispensers. Because they are fragile, they crumble when they hit the bin. The unfrozen water inside them spills out, coating the surrounding ice. This slush refreezes into a solid brick, jamming your auger and potentially burning out the motor.
In this ultimate guide, we will troubleshoot the 5 main causes of low water flow, from the simple 5-minute filter fix to the advanced water valve replacement. Let’s get your ice solid again.
The Mechanics: Why Are My Cubes Hollow?
To fix this, you need to understand exactly how an ice maker works. It’s all about timing.
Your refrigerator does not have a sensor inside the ice mold that says, “Okay, it’s full, stop the water.” Instead, it uses a timer.
When the ice maker calls for water, it sends an electrical signal to the water inlet valve to open for a specific amount of time—usually between 5 to 8 seconds, depending on the brand (Samsung, Whirlpool, GE, etc.).
Scenario A (Normal Pressure): The valve opens. Because you have good low water pressure to the fridge, the water rushes in fast. In 7 seconds, the mold fills to the top. Result: Solid, perfect cubes.
Scenario B (Low Pressure): The valve opens. Because of a clog or kink, the water only trickles in. In 7 seconds, the mold only fills halfway before the timer cuts it off. Result: Ice maker small cubes.
If the water level is critically low, the water creates a thin shell against the cold metal walls of the mold, but there isn’t enough liquid to fill the center. This is how you get ice maker hollow cubes.
So, the troubleshooting question isn’t “Why is the ice small?” The real question is: “What is restricting the flow of water to my fridge?”
Cause #1: A Clogged Water Filter (The 90% Solution)
Before you pull the fridge out or grab a screwdriver, you must check the simplest, most common culprit. A clogged water filter is responsible for the vast majority of low-pressure issues.
The Problem: Your refrigerator water filter is a workhorse. It traps sediment, calcium, rust, and chlorine. Over time, these particles pack tightly into the carbon block. As the filter nears the end of its life, it becomes a bottleneck. The water physically cannot push through the gunk fast enough to fill your ice mold in that short 7-second window.
The Symptoms:
Ice cubes are small, hollow, or misshapen.
The refrigerator water dispenser is not working or is noticeably slower than usual.
You haven’t changed the filter in over 6 months.
The “Bypass” Test If you want to be 100% sure the filter is the problem, you can perform a bypass test.
Remove the old filter.
Install the “bypass plug” (a plastic cap that came with your fridge). If you don’t have one, many modern fridges (like GE and Whirlpool) will automatically bypass the filter if you simply leave the slot empty.
Run the water dispenser. Is the flow strong? If yes, your filter was the clog.
The Fix
Buy the Right Part: Purchase a replacement refrigerator water filter specifically for your model number. Avoid the “super cheap” generics, as they often clog faster.
Flush the System: This is critical. After installing the new filter, run 2-3 gallons of water through the dispenser. This purges trapped air. Air bubbles in the line can cause the water valve to “sputter,” which also leads to small ice cubes.
Cause #2: A Kinked or Blocked Water Supply Line
If the filter is new but the ice is still hollow, the restriction is likely behind the refrigerator.
The Problem: The water line that connects your fridge to the wall is usually a 1/4-inch plastic or copper tube. It is somewhat fragile. If you recently moved the fridge to clean behind it, or if you shoved it back too hard against the wall, you might have kinked the line like a bent garden hose.
The Inspection:
Pull the Fridge Out: Carefully slide the refrigerator straight out from the wall.
Inspect the Line: Trace the tubing from the wall valve all the way to the back of the fridge. Look for pinched sections, sharp bends, or spots where the fridge wheel might be rolling on the line.
Check the Shut-Off Valve: Locate the valve where the water comes from the wall. Ensure it is turned fully open (counter-clockwise). A partially closed valve will restrict flow just enough to cause low water pressure to the fridge.
The “Saddle Valve” Issue
If you have an older home, your fridge might be connected via a “saddle valve” (a clamp-on valve that pierces a copper pipe). These are notorious for failing. The tiny needle hole gets clogged with calcium over time. Even if the valve is “open,” no water can get through. If you have a saddle valve and low pressure, the valve likely needs to be replaced with a proper shut-off valve by a plumber.
Cause #3: Reverse Osmosis (RO) System Issues
This is a very common “hidden” cause for homeowners who have installed under-sink filtration systems.
The Problem: Reverse Osmosis (RO) systems remove impurities, but they also significantly drop water pressure. A standard refrigerator water valve requires at least 20-40 PSI to function correctly. An RO system often only outputs 15-20 PSI.
The Result: The fridge’s inlet valve doesn’t get enough pressure to hold itself open, or the flow is just too weak to fill the mold in time.
The Fix for RO Users
If you have an RO system connected to your fridge:
Check the RO Tank: Is the holding tank heavy (full)? If it’s light, your RO filters might be clogged, reducing pressure further.
Install a Booster Pump: You may need to install an RO booster pump to increase the line pressure to the fridge.
Remove the Fridge Filter: You are double-filtering the water (RO filter + Fridge filter), which kills pressure. Install the fridge’s “bypass plug” to remove the second restriction.
Cause #4: A Failing Water Inlet Valve
If your plumbing is fine and the filter is new, the problem is likely mechanical. The water inlet valve is the part on the fridge that physically opens to let water in.
The Problem: The inlet valve uses electrical solenoids to snap open. Over years of use, two things happen:
The Solenoids Get Weak: They don’t open the valve fully, or they open sluggishly. Instead of 7 seconds of full flow, you get 5 seconds of half-flow.
The Filter Screen Clogs: There is a tiny mesh screen inside the valve where the water line connects. This screen catches debris from your pipes. If it gets clogged with sediment, water flow is strangled.
The Symptoms:
You hear a loud “buzzing” or “humming” sound from the back of the fridge when it tries to make ice, but little water comes out.
Your refrigerator water dispenser not working properly either (since they often share a valve assembly).
How to Fix It
You generally cannot clean these valves; they must be replaced.
Unplug the fridge and turn off the water supply.
Remove the back panel at the bottom of the fridge (usually cardboard or aluminum).
Locate the valve: It is usually on the bottom right, where the blue/white water tubes connect.
Disconnect: Unscrew the water line, unplug the wire harnesses, and push the release rings to pull out the plastic water tubes.
Replace: Install the new refrigerator water inlet valve. It’s an inexpensive part (usually $20-$50).
Cause #5: The Ice Maker Adjustment (Modular Units Only)
If you have an older style “modular” ice maker (common in Whirlpool, Kenmore, and KitchenAid fridges), you might be able to manually adjust the water size.
The Fix: Pop off the white plastic cover on the front of the ice maker head. Look for a small plastic screw with a
+and-sign next to it.The Adjustment: This screw controls the fill timer. Turning the screw toward the
+(usually one full turn) will keep the water valve open for an extra second or two, increasing the size of the cubes.Warning: Only do this if you are sure the water pressure is fine. If you mask a low-pressure problem by adjusting the screw, and then later fix the pressure, your ice maker will overflow and flood your freezer.
Why You Must Fix Hollow Ice Immediately
Ignoring ice maker hollow cubes is dangerous for your appliance. Here is the chain reaction that breaks your fridge:
The Break: Hollow cubes drop into the bin and shatter on impact.
The Leak: The small amount of unfrozen water inside the hollow shell leaks out.
The Freeze: This water runs down into the bottom of the ice bin and freezes all the good cubes together into a giant iceberg.
The Jam: When you press the dispenser lever, the auger motor tries to turn this solid block of ice. It can’t. The motor overheats and burns out, or the plastic drive coupling snaps.
The Cost: You turn a $0 filter fix into a $200 motor repair.
If you see hollow ice, turn off your ice maker immediately (lift the arm or flip the switch) until you fix the water supply problem.
Frequently Asked Questions (FAQ)
Why does my ice maker make small cubes sometimes? This usually indicates a fluctuating water pressure issue in your home. If someone is showering or running the washing machine, the pressure to the fridge might drop temporarily, causing a batch of small cubes. It can also mean your water inlet valve is sticking intermittently.
Can I clean the screen on the water inlet valve? Technically, yes. You can turn off the water, unscrew the supply line, and use a Q-tip or needle to pick debris out of the tiny mesh screen inside the valve port. However, be extremely careful not to puncture the screen. If the screen is heavily calcified, it’s safer to just replace the valve.
My fridge is making a clicking noise and small ice. Are they related? Yes. A refrigerator making a clicking noise is usually a sign of a failing compressor or starter relay. If the compressor is failing, the freezer temperature might fluctuate. If the freezer isn’t cold enough (above 10°F), the ice maker cycles slowly and the cubes may not freeze properly, leading to slushy or small ice production.
What if there is water leaking on the floor behind the fridge? If you have small ice and a refrigerator leaking water on the floor, your water supply line is likely cracked or loose. The water that should be filling your ice mold is instead leaking onto your floor. Pull the fridge out immediately to check the connection.
Conclusion
Don’t settle for “crumbly” ice or a jammed dispenser. Ice maker small cubes are almost always a cry for help from your water supply system.
Follow the triage:
Check the Filter: Is it old? Replace it.
Check the Line: Is it kinked? Straighten it.
Check the Valve: Is it buzzing? Replace it.
By ensuring your fridge has the steady, strong water pressure it needs, you’ll be back to enjoying solid, full-sized ice cubes in your drinks in no time.
