Honeywell air conditioner displays E5 and may shut down or fail to start cooling.

Safety: Unplug the unit. Do not repeatedly reset a unit that is tripping overcurrent protection; this can damage components or wiring.

Steps:

• Check power supply: Verify the outlet voltage with a multimeter if possible. Honeywell portable ACs typically require a dedicated 115V or 230V circuit. Avoid using extension cords or power strips.
• Inspect power cord and plug: Look for discoloration, melting, or loose blades. Replace the power cord if damaged.
• Check for blocked airflow: Severely restricted airflow can cause high current draw. Clean filters, ensure intake and exhaust are not blocked, and verify the exhaust hose is not kinked.
• Listen for compressor and fan: If the fan runs but the compressor hums and trips, the compressor or its start components may be failing. If nothing runs, the main PCB may be at fault.
• Advanced checks (technician recommended): With the unit unplugged, measure compressor winding resistance and check for shorts to ground. Also test fan motor windings. Replace the compressor or fan motor if shorted.
• Control board replacement: If motors test good and supply voltage is stable, the main control board's power electronics may be defective and should be replaced as a complete assembly.