Performed comprehensive maintenance on client's mini-split HVAC system consisting of three units. Diagnosed and resolved heating issue by correcting remote control settings (one set to heat, one to auto). Completed full system service including filter cleaning and inspection of outdoor condenser unit, where mouse nesting material was removed from the condenser fan grill. Interior components and coils were inspected with no further issues found. Provided operational instructions to homeowner on proper remote control usage to prevent future heating problems.