Unit stops cooling and displays E2; fan may still run but compressor cycles off quickly.

Safety: Disconnect power at the breaker or unplug the unit before opening any panels. Sharp metal edges are present around the coil.

Steps:

• Remove front cover: Take off the front grille and any screws securing the indoor cover to expose the evaporator coil (the cold coil at the front of a window or wall unit, or behind the fascia on a split system).
• Locate the evaporator sensor: Look for a small probe or clip-on thermistor attached to the evaporator coil tubing or fins, with two wires leading back to the PCB.
• Check mounting: Ensure the sensor is firmly clipped to the coil. If it has fallen away, reattach it in the original position so it senses coil temperature correctly.
• Inspect wiring and connector: Look for corrosion, broken insulation, or loose connectors. Reseat the plug on the indoor PCB.
• Test resistance: With a multimeter, measure the thermistor resistance at room temperature and compare to the service chart. An open or shorted reading indicates a bad sensor.
• Replace sensor if needed: Install a new Westinghouse evaporator temperature sensor, routing the wires away from moving fan blades and sharp edges.
• Evaluate PCB: If a new sensor does not clear E2, the indoor control PCB may be faulty and should be replaced by a technician.

Note: Do not bend or puncture the refrigerant tubes when working around the coil; refrigerant release is hazardous and requires licensed service.