Unit stops and displays E4, often during heating or defrost cycles

Safety: High-pressure refrigerant circuits are hazardous. Do not open the sealed system. Only licensed technicians should handle refrigerant.

User-level checks:

• Clean filters: Turn off power, remove indoor filters, and wash with mild soap and water. Dry completely before reinstalling.
• Check outdoor airflow: Ensure the outdoor unit is not blocked by debris, plants, or walls. Maintain at least 30–50 cm clearance around the unit.
• Clean condenser coil: With power off, gently brush or vacuum the outdoor coil fins. For heavy dirt, use a coil cleaner suitable for aluminum fins, following instructions.
• Verify outdoor fan operation: Restore power and observe the outdoor unit. The fan should start when the compressor runs. If the fan does not run, shuts off intermittently, or makes grinding noises, the fan motor or capacitor may be faulty.

Technician-level checks (do not attempt without training):

• Measure system pressures and verify refrigerant charge.
• Test the high-pressure switch or pressure sensor and wiring.
• Inspect for non-condensables or blocked capillary/expansion device.

If E4 recurs after cleaning and ensuring airflow, contact an authorized Electrolux service center.