Display shows E7; unit may run fan only or shut down cooling; sometimes appears after long operation in high heat.

Safety: Unplug the unit. The compressor and discharge line can be extremely hot; allow the unit to cool before touching internal components.

Steps to address E7:

• Access compressor compartment: Remove the outer shell (window unit) or rear panel (portable) to expose the compressor and discharge line.
• Locate discharge sensor: Look for a thermistor clipped or strapped to the small-diameter copper line leaving the compressor (discharge line).
• Check mounting and insulation: Ensure the sensor is firmly attached to the line and any insulating sleeve is intact. Re-secure if loose.
• Clean condenser coil: Dust and debris on the condenser coil can cause high discharge temperatures. Use a soft brush and low-pressure air or vacuum to clean the fins thoroughly.
• Test sensor: With power off, disconnect the sensor and measure resistance. Compare to other thermistors in the unit or manufacturer specs. Replace if open, shorted, or clearly out of range.
• Replace sensor: Install a new compressor discharge temperature sensor if needed, securing it tightly to the discharge line.
• Persistent E7: If E7 returns after cleaning and sensor replacement, the system may be overcharged, undercharged, or have restricted airflow/refrigerant flow. This requires a licensed HVAC technician to diagnose pressures and possibly replace the main control board if its sensor circuit is faulty.