CoolSys is seeking a Mid-Level Start-Up Technician to support construction and service projects across commercial and industrial sites. In this hands-on field role, you will commission, troubleshoot, and maintain HVAC-R and refrigeration systems, ensuring safe, efficient, and reliable operation. Partnering with project teams and customers, you'll perform start-ups, diagnostics, and repairs while following strict safety and quality standards. CoolSys offers ongoing technical training, advancement opportunities, and the chance to contribute to energy-efficient, sustainable mechanical solutions nationwide. Responsibilities Install, service, and maintain commercial HVAC-R and refrigeration systems on construction and retrofit projects. Troubleshoot mechanical, electrical, and refrigeration issues to restore system performance. Perform preventive maintenance and inspections to ensure safety, reliability, and efficiency. Interpret blueprints, plans, and wiring diagrams for proper installation and repair. Document service activities, parts used, and recommendations in company systems. Collaborate with project teams, contractors, and customers to deliver on-time, quality work. Follow all Cool Sys and site safety standards, PPE use, and regulatory requirements. Support continuous improvement, technical training, and adoption of energy-efficient solutions. Required Skills HVAC-R systems troubleshooting Commercial refrigeration service Equipment installation Preventive maintenance Mechanical diagnostics Electrical schematics reading Brazing and piping EPA 608 compliance Use of HVAC-R service tools Service documentation