Unit displays E2 and may shut down cooling; fan may continue to run intermittently.

Safety warning: Unplug the air conditioner before opening the cabinet. Sharp metal edges are present; wear cut-resistant gloves.

Diagnostic and repair steps:

• Access the evaporator: Remove the front grille and air filter. On many Hotpoint window and portable units, the evaporator coil is directly behind the filter.
• Locate the evaporator sensor: Look for a small probe or clip-on sensor attached to the evaporator fins or tubing, with two wires leading back to the control board.
• Check mounting: Ensure the sensor is firmly clipped to the coil. If it has fallen away, reattach it in the original position so it can accurately sense coil temperature.
• Inspect wiring and connector: Follow the sensor wires to the PCB. Check for cuts, abrasions, or loose connectors. Reseat the connector on the board.
• Test resistance: With power disconnected, unplug the sensor and measure resistance. Compare to the ambient sensor if they are the same part type; a large discrepancy or 0 Ω / OL indicates a bad sensor.
• Replace sensor if needed: Install a new Hotpoint evaporator thermistor, securing it to the coil and routing wires away from moving parts.
• Reassemble and test: Reinstall the filter and grille, restore power, and run the unit. Confirm that E2 no longer appears.

Note: Persistent E2 with a known-good sensor may indicate a faulty main control board.