Responded to customer complaint regarding recurring "Control Hardware Error" code 125 on thermostat and efficiency concerns. Diagnosed thermostat malfunction and ordered replacement unit. Adjusted humidification settings to 30% maximum to reduce indoor moisture and prevent window icing. Modified heat pump balance point from 20°F to 35°F to transition to gas furnace operation sooner during cold weather for improved efficiency. Documented damage to outdoor unit coils/fins with photos for future follow-up.
