We have to go back to 1933 to find out where this company began. We have had different owners, with some name changes, but our yellow diamond and our commitment to excellence and quality workmanship have kept us on top over the years. We are proud to be the contractor of record on the projects that have and continue to change the Cleveland Skyline.


Reliance Mechanical Contractors Inc. was founded in 1933 by Samuel H. Gevelber. The original location was on the westside of Cleveland. The company moved to its present location of 4975 Hamilton Avenue in 1948.

July 26, 1966, William F. Neiheiser became a partner in Reliance Mechanical Contractors Inc., along with Fred Gevelber and Hyman Weiner.

In 1983, Reliance Mechanical Contractors Inc. was split into two separate entities, Reliance Mechanical Corp. and Reliance Mechanical Inc. The owners of Reliance Mechanical Corp, which remained the mechanical contracting part of the business, were William F. Neiheiser and William N. Neiheiser. Reliance Mechanical Inc. which maintained all the investments was kept by the original two owners, Fred Gevelber and Hyman Weiner.

June 30, 1993, William N. Neiheiser became the sole owner of Reliance Mechanical Corp.

July 1, 2000, William N. Neiheiser sold Reliance Mechanical Corp to Unicom Mechanical Services. Unicorn Mechanical Services merged with Exelon Corp in October of 2000. Reliance Mechanical was owned by Exelon Corp. under the Exelon Services umbrella from July 1, 2000 until March 8, 2004.

March 8, 2004, William N. Neiheiser bought Reliance Mechanical in an asset sale from Exelon Corp under a new formed company RMC Mechanical Company LLC.

July 1, 2005 RMC Mechanical Company LLC and Reliance Mechanical LLC merged with the operating company going forward as Reliance Mechanical LLC.

October 2009, the employees of Reliance Mechanical LLC formed a new company, RELMEC Mechanical LLC which is the operating company today. The company has had a steady growth and today is capable of handling many projects running into millions of dollars in size. It employs a field force of 100+ plumbers and pipefitters. Relmec Mechanical has completed work for industry, major hospitals, research facilities, educational, office building, sports complexes, etc.


Relmec Mechanical LLC is a full service Mechanical Contractor providing HVAC, plumbing, fire protection and process piping installations. Our annual volume is approximately 60 million dollars. We employ 35 full time employees departmentalized into management, accounting, engineering, estimating, purchasing and supervision. We employ over 100 union tradesman comprised of pipefitters, plumbers and laborers.

Relmec Mechanical LLC has 35 full time HVAC and Plumbing service technicians specializing in preventative maintenance, troubleshooting and contract start-up.