Digital Proline upright freezer displays E1 and stops cooling or runs continuously without reaching set temperature.

Safety first: Unplug the freezer from the mains before removing any panels. Use insulated tools and avoid working on live circuits.

Steps to check and address E1:

• 1. Power reset: Unplug the freezer for 5–10 minutes, then plug it back in. If E1 clears temporarily and returns, continue with diagnosis.
• 2. Locate the cabinet sensor: On most Proline freezers, the cabinet NTC sensor is clipped behind the inner liner, often near the top or rear wall, or inside a small plastic cover. Remove the cover carefully.
• 3. Inspect wiring and connector: Check the sensor leads for cuts, pinches, or corrosion. Ensure the connector at the sensor and at the main control PCB (usually in the top or rear control box) is fully seated.
• 4. Test the sensor: With the unit unplugged, disconnect the sensor from the harness and measure its resistance with a multimeter. At room temperature (around 20–25°C), most Proline NTC sensors read between 4–15 kΩ (check service data if available). If the reading is open (OL), shorted (near 0 Ω), or far outside expected range, the sensor is faulty.
• 5. Replace the sensor if defective: Order a compatible Proline freezer cabinet NTC sensor. Clip or screw the new sensor into the original position, route the wires along the original path, and reconnect to the harness and control board.
• 6. Reassemble and test: Refit any covers, restore power, and set the temperature. Allow several hours for the freezer to stabilize and confirm that the E1 code does not return and that the internal temperature is correct.

When to call a technician: If the sensor tests good but E1 persists, the main control PCB may be faulty and should be diagnosed or replaced by a qualified technician.