Amentum is seeking an experienced and highly skilled Chiller Plant Mechanic to provide advanced technical expertise supporting critical utility infrastructure at a premier pharmaceutical research and development facility in Groton, CT. This role is essential to ensuring the reliable, safe, and efficient operation of the central chiller plant and utility systems that directly enable pharmaceutical manufacturing, laboratory, and research activities.
The Chiller Plant Mechanic is a highly skilled technical specialist responsible for the safe, reliable, and efficient operation, maintenance, troubleshooting, and optimization of large-capacity centrifugal, screw, and absorption chiller plants (typically 500–5,000 tons per machine) serving critical process cooling, HVAC, and utility systems. This role requires advanced expertise in high-tonnage water-cooled chiller systems, associated primary/secondary chilled water and condenser water systems, refrigerant management, controls integration, and predictive/preventive maintenance practices in a regulated industrial or pharmaceutical environment.
Key Responsibilities
Perform advanced diagnostics, troubleshooting, and repair of large centrifugal and absorption chillers, including compressors, purge systems, economizers, oil recovery systems, motor starters, VFDs, and associated instrumentation.
Execute complex mechanical repairs: compressor rebuilds or replacements, tube cleaning/replacement, shaft alignment, bearing replacement, seal work, and heat exchanger maintenance.
Manage refrigerant handling, recovery, charging, leak detection, and documentation in full compliance with EPA Section 608 (Type II/III or Universal preferred) and site environmental requirements.
Operate and maintain primary chilled water pumps, condenser water pumps, cooling towers, filters, chemical treatment systems, and related distribution infrastructure.
Interpret and work from P&IDs, electrical one-lines, control schematics, OEM manuals, and trending data from building automation systems (BAS/BMS) and chiller plant controls.
Lead or support predictive maintenance activities including vibration analysis, infrared thermography, oil analysis, ultrasonic testing, and performance efficiency calculations (kW/ton, approach temperatures, etc.).
Respond to and resolve critical chiller plant upsets, alarms, and capacity shortfalls with minimal downtime impact on production or research operations.
Develop, update, and execute preventive maintenance procedures, job plans, and lockout/tagout (LOTO) packages specific to large chiller systems.
Mentor mechanics and operators on chiller plant theory, safe work practices, and troubleshooting techniques.
Coordinate with vendors, OEM technicians, and engineering for major overhauls, tube inspections, motor rewinds, and capital upgrade projects.
Maintain accurate work order documentation, parts usage, refrigerant logs, and equipment history in the computerized maintenance management system (CMMS).
Support continuous improvement initiatives focused on energy efficiency, reliability (MTBF), and reduction of unplanned downtime.
Strictly adhere to all site safety, environmental, GMP, and regulatory requirements (OSHA, EPA, NFPA, site-specific permits).
This position is critical to maintaining uninterrupted cooling capacity for research, manufacturing, and facility operations. The ideal candidate will bring deep technical mastery of large chiller systems combined with a proactive, safety-first approach to plant reliability.
As an Amentum Technician supporting our pharmaceutical client, you are expected to:
One Team Mentality: Work collaboratively in a team environment; be friendly, respectful, empathetic, and professional toward teammates and clients at all times.
Respect & Inclusion: Value and respect employee authenticity and demonstrate cultural awareness to foster a welcoming, memorable, and respectful workplace.
Workload Management: Balance multiple tasks and priorities while maintaining strong attention to detail; demonstrate flexibility when shifting priorities as requested by management.
Initiative & Problem-Solving: Take ownership to resolve issues independently within scope; escalate appropriately; remain adaptable and solutions-focused under changing conditions.
Communication
Knowledge of Microsoft Windows, Word, Excel, Outlook and SharePoint
Ability to communicate clearly via phone
Ability to work closely with customer during site emergencies.
Excellent oral and written communications
Excellent interpersonal skills, i.e., listening to customer needs, articulating path forward and giving solutions that provide value to the customer, etc.
Accurately document electronic and paper cataloging system to provide information to customer or regulatory personnel.
Strive for quick complaint resolution; to resolve problems on the first call and avoid escalation of issues through operational knowledge.
High School Diploma or GED equivalent. Technical/vocational training, apprenticeship, or military experience in industrial maintenance, power plant operations, stationary engineering, or mechanical trades strongly preferred. Associate’s or Bachelor’s degree in Mechanical Engineering Technology, Industrial Maintenance, or related field is a plus.
Minimum five 5 years of hands-on experience maintaining and repairing large industrial centrifugal and/or screw chiller plants (500+ ton machines preferred).
Advanced-level expertise demonstrated through progressively responsible roles is required.
Demonstrated expertise with major OEM platforms (Carrier, Trane, York/Johnson Controls, Daikin, or equivalent large tonnage equipment).
Strong working knowledge of chilled water system hydraulics, cooling tower operation, water chemistry, and energy optimization strategies.
Proven ability to diagnose complex mechanical, electrical, and controls-related chiller failures under time pressure.
Proficiency reading technical drawings, electrical schematics, and using diagnostic tools (multimeters, megohmmeters, vibration analyzers, refrigerant analyzers, etc.).
Strong mechanical skills including hydraulics, pneumatics, precision alignment (laser preferred), bearing/seal replacement, and basic electrical troubleshooting (motors, starters, VFDs, MCCs).
Experience with Computerized Maintenance Management Systems (CMMS) for work order management, asset data integrity, and reporting. Ability to read and interpret P&IDs, mechanical drawings, schematics, and OEM technical manuals.
Excellent verbal and written communication skills with the ability to interface professionally with technicians, engineers, management, vendors, and client stakeholders across all levels.
Proven ability to work safely, independently, and with high attention to detail in a fast-paced, highly regulated environment while consistently meeting compliance, quality, and schedule requirements.
Valid driver’s license; ability and willingness to work overtime, weekends, holidays, and participate in on-call rotations to support 24/7 utility operations.
Must be a U.S. Citizen or Permanent Resident. Ability to obtain and maintain site-specific access authorization, including comprehensive background checks and drug screening.
Ability to pass a medical evaluation for respirator use and successfully complete quantitative fit testing for required respirator types.
Connecticut S-1 or S-2 Heating, Piping, and Cooling (HPC) License
EPA Section 608 Universal Certification (refrigerant handling) or ability to obtain within 60 days of hire.
Journeyman HVAC/R or industrial mechanic license/certification.
Experience with absorption chillers, magnetic bearing compressors, or low-GWP refrigerant conversions.
Familiarity with BAS/BMS platforms (Siemens, Schneider, Johnson Controls, etc.) and chiller plant optimization sequences.
CMRP, HVAC Excellence, or equivalent professional credentials.
Prior leadership or mentoring experience in a multi-skilled utility team.
Some physical/special requirements include:
Regularly lift to 50 lbs
Regularly climb ladders, steps, and scaffolding
Repetitive motions: bend, stoop, squat, kneel, stretch, reach, wrist movement
Walk extensively throughout the plant during shift
Work at an accelerated pace in emergency conditions
Ability to differentiate colors pertaining to wire color-coding
Wear steel toe safety shoes, safety glasses, gloves, hard hats, and other Personal Protective Equipment as needed.
Cope with demands (stressors) that are associated with the job and/or the work environment.
Compensation Details:
35.00-45.00
The compensation range or hourly rate listed for this position is provided as a good-faith estimate of what the company intends to offer for this role at the time this posting was issued. Actual compensation may vary based on factors such as job responsibilities, education, experience, skills, internal equity, market data, applicable collective bargaining agreements, and relevant laws.
Benefits Overview:
Our health and welfare benefits are designed to support you and your priorities. Offerings include:
Health, dental, and vision insurance
Paid time off and holidays
Retirement benefits (including 401(k) matching)
Educational reimbursement
Parental leave
Employee stock purchase plan
Tax-saving options
Disability and life insurance
Pet insurance
Note: Benefits may vary based on employment type, location, and applicable agreements. Positions governed by a Collective Bargaining Agreement (CBA), the McNamara-O'Hara Service Contract Act (SCA), or other employment contracts may include different provisions/benefits.
Original Posting:
08/04/2026 - Until Filled
Amentum anticipates this job requisition will remain open for at least three days, with a closing date no earlier than three days after the original posting. This timeline may change based on business needs.
Amentum is proud to be an Equal Opportunity Employer. Our hiring practices provide equal opportunity for employment without regard to race, sex, sexual orientation, pregnancy (including pregnancy, childbirth, breastfeeding, or medical conditions related to pregnancy, childbirth, or breastfeeding), age, ancestry, United States military or veteran status, color, religion, creed, marital or domestic partner status, medical condition, genetic information, national origin, citizenship status, low-income status, or mental or physical disability so long as the essential functions of the job can be performed with or without reasonable accommodation, or any other protected category under federal, state, or local law. Learn more about your rights under Federal laws and supplemental language at Labor Laws Posters
Amentum is a global leader in advanced engineering and innovative technology solutions, trusted by the United States and its allies to address their most significant and complex challenges in science, security and sustainability. Our people apply undaunted curiosity, relentless ambition and boundless imagination to challenge convention and drive progress. Our commitments are underpinned by the belief that safety, collaboration and well-being are integral to success. Headquartered in Chantilly, Virginia, we have approximately 50,000 employees in more than 70 countries across all 7 continents.
