Indoor unit shows H8, unit may run but with abnormal performance

Safety first: Turn off power before cleaning or opening panels. Coil fins are sharp.

• Clean filters: Remove and wash indoor air filters with mild detergent. Dry completely before reinstalling.
• Inspect indoor coil: If accessible, check for ice buildup or heavy dust. Allow ice to melt naturally with power off, then clean the coil gently.
• Check airflow: Ensure all supply louvers are open and that furniture or curtains are not blocking airflow.
• Fan operation: Verify that the indoor fan runs at all speed settings. If weak, see indoor fan motor diagnostics (E9/H2).
• Technician tasks: If H8 persists with clean filters and good airflow, a technician should check refrigerant charge and system operation.