Display shows E3 and compressor may not start or may shut off quickly; unit may blow room-temperature air.

Safety first: Unplug the unit. If it has been running, allow 10–15 minutes for components to cool before working near the condenser area.

Steps:

• Access the condenser section: For window units, remove the outer shell or rear cover as per the user manual. For portable units, remove the rear panel.
• Locate the condenser sensor: Find the outdoor/condenser coil (the warm coil at the back). Look for a clip-on or inserted sensor attached to the coil tubing or fins.
• Check physical condition: Ensure the sensor is firmly attached and not hanging loose. Inspect for melted insulation or crushed wires near the compressor or fan motor.
• Inspect and reseat connector: Trace the sensor wires to the main PCB and reseat the connector.
• Test sensor: With a multimeter, measure resistance across the sensor leads. Compare to expected NTC values or to another identical sensor in the unit. Replace if open, shorted, or far out of range.
• Install replacement: Fit a new Hotpoint condenser thermistor, clip it securely to the coil, and secure wiring with cable ties away from hot discharge lines and fan blades.
• Reassemble and test: Refit the rear cover, restore power, and run the unit in COOL mode to verify that E3 is cleared.

Warning: Do not bend refrigerant tubing aggressively; this can cause leaks that require professional repair.