Rheem ductless indoor unit displays E2 and stops cooling; coil may ice up or unit may short cycle.

Safety first: Turn off power at the breaker and disconnect. Wait several minutes before removing covers.

• Access the sensor: Remove the front panel and air filters. Carefully remove the plastic shroud to expose the evaporator coil. Locate the small thermistor clipped to the coil (usually near the center).
• Check placement: Ensure the thermistor is firmly clipped to the coil tubing and not hanging loose. Reclip it tightly if it has come off.
• Inspect wiring: Follow the thermistor wires back to the indoor PCB. Look for pinched, cut, or chewed wires. Repair or replace damaged wiring.
• Test resistance: With power off, disconnect the thermistor from the board and measure its resistance with a multimeter. Compare to Rheem’s temperature/resistance chart for your model. A reading of 0 Ω (short) or infinite (open) indicates a bad sensor.
• Replace if faulty: If readings are out of spec, replace the evaporator temperature sensor with the correct Rheem thermistor kit and reconnect securely.

Warning: Do not bend or puncture the evaporator coil while accessing the sensor. Coil damage can cause refrigerant leaks and require major repair.