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In 1976, Harry Hartigan, a young service technician and recent US Navy veteran, founded Hartigan Refrigeration. What began as a company focusing on gasoline vapor recovery refrigeration systems rapidly expanded its scope to encompass process cooling and HVAC over the next few years. In 1978, the company underwent a name change to Mechanical Service Corporation (MSC), reflecting Harry's vision for the future as a specialized service provider dedicated to diagnostics and remediation for advanced mechanical systems. This strategic shift laid the foundation for what MSC has become today: a company renowned for its expertise in cutting-edge mechanical solutions.

Vice President Tim Hartigan's journey with MSC began in 1997 as a service shop helper. After completing the UANJ HVAC/R training program, he worked his way through the ranks as an Apprentice, Salesperson, VP of Sales, General Manager, Vice President, and Partner. While his father, Harry, focused on honing and expanding MSC's technical capabilities, Tim concentrated on business development, playing a pivotal role in solidifying the company's status as the Northeast Region's premier specialist in complex system service and diagnostics. Tim's unwavering commitment and leadership left an indelible mark on MSC's growth and success. His untimely passing in 2019 was a profound loss for the company, and his absence is still deeply felt.

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Hartigan Refrigeration is established, focusing on servicing vapor recovery refrigeration systems for the petroleum industry

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The company is renamed Mechanical Service Corporation to reflect our expansion into HVAC service and process cooling

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Tim Hartigan joins MSC as a service shop helper and progresses through the ranks to V.P. and Partner over the next two decades

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We grow our standing as the region's top service specialist, serving clients ranging from modest production facilities to complex BSL-4 labs

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Professional Engineer Andrew Heilmann is appointed President following 11 years as Staff Engineer and  

General Manager

​In 2024, Harry Hartigan passed the leadership baton to our new company president, Andrew Heilmann, P.E.


Andrew began his career at MSC in 2009 as a college student at Rensselaer Polytechnic Institute, spending his summer and winter breaks working as a field assistant. Harry Hartigan mentored Andrew from an early age when he recognized his young neighbor's natural mechanical aptitude and avid interest in the HVAC trade. Andrew joined MSC full-time as lead project manager after graduating from RPI in 2013, overseeing installation projects while contributing in-house and field engineering. From 2017 to 2019, he assisted Tim Hartigan in operations responsibilities, ultimately taking over as GM after Tim's passing. His hard work paid off in 2019 when he passed the Professional Engineering exam, becoming a licensed P.E. in the State of New Jersey.

Harry has stepped back to an advisory position supporting the service and engineering teams and continues to play an integral role at the company.

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