my new dumos ice maker just runs the fan constantly and never makes ice, the water's full and it's been hours.

Diagnosis

When a DUMOS countertop ice maker runs the fan continuously without ever initiating the freezing cycle, it typically indicates a failure in the thermal sensor loop or a "stuck" compressor protection timer. The fan is designed to dissipate heat from the condenser coils; however, if the unit cannot detect a drop in temperature at the evaporator pins (the silver spikes), it will never trigger the harvest cycle to drop the cubes. This is often caused by a "thermal lock" where the unit thinks it is overheating or is trapped in a safety delay mode intended to protect the compressor from short-cycling. You can confirm this by touching the side walls of the unit. If the fan is roaring but the exterior casing feels lukewarm or cold—rather than hot to the touch—the compressor is not actually engaging. If the casing is extremely hot, the unit is struggling with ambient heat and the internal thermostat is preventing the cooling cycle from starting to avoid motor burnout. Another common culprit is an air bubble trapped in the water pump line, preventing water from reaching the freezing pins, which means the sensor never detects the liquid-to-solid transition required to move to the next phase.

How to Fix It

To reset the internal logic board and force a hard start of the refrigeration cycle, follow these precise steps:

1. Power down the unit by pressing the Power button and then physically disconnecting the power cord from the wall outlet.
2. Leave the unit unplugged for exactly 15 minutes. This allows the internal capacitors to discharge and resets the compressor delay timer.
3. While the unit is off, remove the ice basket and use a clean cloth to wipe the evaporator pins (the silver spikes) to ensure no debris or mineral buildup is insulating the pins.
4. Ensure the unit is placed on a flat, level surface with at least 6 inches of clearance on all sides. If it is pushed against a wall, the fan will blow hot air back into the intake, triggering the overheat sensor.
5. Plug the unit back into a dedicated wall outlet (avoid using power strips or surge protectors, as these can cause voltage drops that prevent the compressor from kicking in).
6. Press the Power button and immediately select the "Small" ice setting. This requires less energy to freeze and is the fastest way to test if the cycle is functioning.
7. Wait 10 minutes. You should hear a distinct "click" followed by a low hum; this is the compressor engaging. Once you hear this, the fan should modulate its speed.

If That Didn't Work

• Perform a "Prime" Sequence: If the fan is running but no water is appearing on the pins, the pump may be air-locked. Fill the reservoir to the "MAX" line with distilled water. Gently tilt the machine 5-10 degrees forward and backward while it is running to help the pump prime and push air bubbles out of the internal tubing.
• Temperature Calibration: If the room is above 90°F, the unit may enter a protective standby mode. Move the machine to a cooler environment or run an air conditioner in the room. The DUMOS sensors are highly sensitive to ambient heat and will prioritize fan cooling over ice production if the internal temperature exceeds a specific threshold.
• Water Quality Reset: Heavy mineral buildup from hard water can coat the sensors. Drain all water from the reservoir using the drain plug at the bottom. Fill it with a mixture of 50% white vinegar and 50% warm water. Let it sit for 30 minutes, then run one full cycle of "ice" (even if it doesn't freeze) to clear the lines, then flush with fresh water.
• Check for Voltage Drops: If you are using an extension cord, remove it. These machines require a high initial burst of amperage to start the compressor. If the voltage drops even slightly, the fan will run (low power) but the compressor (high power) will fail to engage.

Heads Up

• Always use filtered or distilled water to prevent calcium deposits on the evaporator pins, which can trick the sensors into thinking the ice has already formed.
• Avoid opening the lid frequently during the first 10 minutes of a cycle; introducing warm room air can reset the temperature sensor and delay the first batch of cubes.
• Clean the external air intake vents every two weeks with a vacuum or compressed air to ensure the fan can efficiently cool the condenser.
• Do not operate the machine immediately after moving it or tilting it; let it sit upright for 2 hours to allow the refrigerant oil to settle back into the compressor.