AAON/LG VRF Field Service Diagnostic Technician

Role Snapshot

Drive reliable comfort in commercial buildings by installing, supporting, starting up, commissioning, troubleshooting, maintaining, and repairing advanced HVAC systems—with emphasis on AAON and LG platforms. Work cross-functionally with customers, service management, controls teams, contractors, and manufacturers to resolve mechanical and controls-related issues efficiently and professionally.

Core Impact Areas

• Service & Troubleshooting
  • Diagnose and repair: AAON packaged rooftop units, AAON air handlers, LG VRF, LG heat-pump and heat-recovery, DX/refrigeration, hydronic systems, plus VFDs, motors, compressors, fans, and related components.
  • Triage electrical, mechanical, refrigeration, and controls faults to root cause.
  • Test systems and verify proper operation post-repair.
• Start-Up & Commissioning
  • Perform factory start-ups and complete all manufacturer documentation.
  • Verify refrigerant charge, airflow, temperatures, pressures, electrical characteristics, safeties, and sequences.
  • Partner with controls technicians for BMS integration, functional testing, and BAS-related troubleshooting.
• Preventive Maintenance
  • Execute scheduled PM on coils, filters, belts, bearings, motors, compressors, electrical components, dampers, economizers, and refrigeration systems.
  • Identify developing problems and recommend corrective actions.
  • Deliver equipment condition reports and repair recommendations to customers.
• Customer Service & Documentation
  • Communicate clearly with facility managers and other trades; represent DMG with professionalism.
  • Respond to emergency/after-hours calls as required.
  • Complete accurate service reports: conditions, diagnostics, readings, repairs, recommendations, photos, equipment info, and part numbers.
  • Maintain precise labor, travel, and material records; highlight repair/replacement opportunities to the Service & Controls sales team.

Qualifications

• Preferred: 3+ years in commercial HVAC service.
• Strong knowledge of commercial HVAC and refrigeration fundamentals.
• Ability to read electrical schematics/wiring diagrams.
• Mechanical/electrical troubleshooting proficiency and skilled use of diagnostic instruments.
• Valid driver’s license; acceptable driving record.
• Self-directed with excellent written and verbal communication; able to manage multiple calls.
• Safety-first mindset in commercial/industrial settings.

Preferred Background

• Servicing AAON equipment and LG VRF systems.
• AAON factory training/certification and LG VRF training/certification.
• Experience performing start-up and commissioning.

Physical Requirements

• Lift/carry HVAC tools and components.
• Climb ladders; access rooftops.
• Work in confined spaces/mechanical rooms.
• Operate outdoors in varying weather.

Join us to solve complex HVAC challenges and keep high-performance systems running at their best.