Unit displays H1 and may run in a low-power mode or delay compressor start.

Safety: Unplug the unit before accessing outdoor components. Be cautious of icy surfaces.

Steps to address H1:

• Allow defrost cycle: H1 may indicate an automatic defrost. Allow the unit to run its cycle; the code should clear when complete.
• Inspect outdoor coil: Check for heavy frost or ice. If present, turn the unit off and allow it to thaw naturally. Do not chip ice with sharp tools.
• Clean coil: Once thawed, clean the outdoor coil fins of dirt and debris to improve airflow.
• Check outdoor sensor: Locate the outdoor coil thermistor and ensure it is properly attached and wired. Replace the outdoor coil temperature sensor if faulty.
• Persistent H1: If H1 remains even in moderate temperatures with a clean coil and good sensor, the main control board may be mismanaging defrost and should be replaced by a technician.