Display shows E9 and the unit may not cool or may cycle off quickly.

Safety: Disconnect power before accessing the evaporator area or control board.

Steps to address E9:

• Power reset: Unplug for 10 minutes and plug back in. If E9 returns, continue.
• Locate low-temp sensor: Some Whynter models use a dedicated low-temperature sensor on the evaporator or near the coldest part of the cabinet. Access it by removing the interior rear panel.
• Inspect sensor placement: Ensure the sensor is clipped where the manufacturer intended and not touching bare metal in a way that could cause extreme readings.
• Check wiring and connectors: Look for damage or corrosion along the sensor wires and at the control board connector.
• Test and replace: Measure resistance with a multimeter. If the reading is abnormally low (indicating a short) or does not change with temperature, replace the sensor with a Whynter-compatible part.

If the sensor is good but E9 persists, the main control board may be faulty and should be replaced or evaluated by a technician.