Display shows E3 and the ice maker stops mid-cycle or never enters harvest.

Safety: Unplug the ice maker and close the water supply valve before working inside the cabinet.

Clean and inspect first:

• Locate the ice thickness sensor: On many Summit models, this is a metal probe or plastic sensor near the evaporator plate that detects ice slab thickness or water level.
• Clean mineral buildup: Use a food-safe ice machine cleaner or a 1:1 vinegar-water solution. Gently scrub the probe with a soft brush or cloth to remove scale and slime. Rinse thoroughly.
• Check alignment: Ensure the sensor is positioned correctly relative to the evaporator or water curtain as per the user manual. Misalignment can trigger E3.
• Inspect wiring: Verify that the sensor harness is intact and firmly connected to the control board.

Test and replace:

• If the sensor is a simple conductivity probe, check for continuity between terminals when submerged in water (per manual). If it shows no change, it may be defective.
• Order a replacement ice thickness sensor / ice level probe specific to your Summit model and install it in the same position and orientation.
• If a new sensor does not clear E3, the main control board may be misreading the signal and require replacement.

Tip: Regular descaling of the ice maker reduces sensor errors caused by mineral deposits.