Commercial HVAC VRF Commissioning Specialist — AAON & LG Systems

Ambient Enterprises; Orange (CA); On-site; USD 65,000 - 95,000; Full time

Job summary

DMG is seeking a Commercial HVAC VRF Commissioning Specialist to perform installation, start-up, commissioning, maintenance, and repair of AAON and LG systems on customer sites. The role covers electrical, mechanical, refrigeration, and controls, with hands-on work on rooftop units and VRF systems.

You will verify installations, document results, and coordinate with controls technicians for BMS integration, while providing clear service reports and recommendations.

Qualifications

• 3+ years of commercial HVAC service experience.
• Fluency in reading electrical schematics and wiring diagrams.
• Proven mechanical and electrical troubleshooting capability; adept with diagnostic instruments.
• Valid driver’s license with an acceptable driving record.

Responsibilities

• Install, support, start-up, commissioning, maintenance, and repair of commercial HVAC equipment with focus on AAON and LG platforms.
• Troubleshoot across electrical, mechanical, refrigeration, and controls domains.
• Coordinate with controls personnel for BMS integration and testing; assist with BAS-connected equipment.
• Deliver field service reports with conditions, diagnostics, readings, repairs, and part numbers.

Skills

HVAC troubleshooting

Electrical schematics

Commissioning start-up

Field service

Communication

Tools

Diagnostic instruments

Job description

Commercial HVAC VRF Commissioning Specialist — AAON & LG SystemsPicture your day: You review the morning dispatch, load your gauges and meters, and head to a downtown rooftop where an AAON packaged unit is ready for start-up. You verify airflow, confirm refrigerant charge, check safeties, and document electrical characteristics. By midday, you’re indoors commissioning an LG VRF heat-recovery system, walking a facility manager through operating sequences and confirming BMS integration with a controls technician. In the afternoon, you’re troubleshooting a hydronic loop, tracking down a VFD fault to a failing fan motor—and you close the loop with a clear service report, photos, part numbers, and recommendations. That’s a typical day for our AAON & LG HVAC Service Technician at DMG.What You’ll OwnInstallation, support, start-up, commissioning, maintenance, and repair of commercial HVAC equipment with a primary focus on AAON and LG platforms.Service & troubleshooting across electrical, mechanical, refrigeration, and controls domains—finding root causes, not just symptoms.Hands-on work on AAON packaged rooftop units, AAON air-handling equipment, LG VRF systems, LG heat-pump and heat-recovery systems, DX and refrigeration systems, hydronic heating and cooling, and VFDs, motors, compressors, and fans.System testing and operational verification after repairs or adjustments.Start-Up & Commissioning ExcellenceExecute factory start-ups for AAON and LG equipment; complete all manufacturer documentation accurately.Verify refrigerant charge, airflow, temperatures, pressures, electrical characteristics, safety circuits, and operating sequences.Coordinate with controls personnel for BMS/Building Automation System integration and functional testing; assist with troubleshooting of BAS-connected equipment.Preventive Maintenance That PreventsPerform scheduled PM on coils, filters, belts, bearings, motors, compressors, electrical components, dampers, economizers, and refrigeration circuits.Identify developing issues early and recommend corrective actions.Provide customers with clear condition reports and prioritized repair options.Customer PartnershipCollaborate daily with customers, service management, controls specialists, contractors, and manufacturers.Explain findings and fixes in plain language; represent DMG with a professional attitude and appearance.Respond to emergency and after-hours calls as needed.Documentation That Tells the StoryDeliver accurate field service reports for every visit.Record conditions, diagnostics, readings, repairs, and recommendations—include photos, equipment details, and part numbers when useful.Track labor, travel, and materials precisely.Flag repair/replacement opportunities for the Service & Controls sales team.What You Bring3+ years of commercial HVAC service experience (preferred).Deep understanding of commercial HVAC systems and refrigeration fundamentals.Fluency in reading electrical schematics and wiring diagrams.Proven mechanical and electrical troubleshooting capability; adept with diagnostic instruments.Valid driver’s license with an acceptable driving record.Independent, organized, and able to manage multiple service calls with strong written and verbal communication.Commitment to working safely in commercial and industrial environments.Bonus PointsExperience servicing AAON equipment and LG VRF systems.AAON factory training/certification and LG VRF training/certification.Hands-on background in equipment start-up and commissioning.Physical RealitiesLift and carry HVAC tools and components as needed.Climb ladders and access rooftops safely.Work in confined spaces and mechanical rooms.Operate outdoors across varying weather conditions.If you thrive on complex diagnostics, precise commissioning, and clear communication, you’ll feel right at home here.