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Union Boiler Company Limited
Mechanical Contractors Since 1966

Welcome to Union Boiler Company Limited

We are a mechanical contracting company based out of Hamilton, Ontario.

24 Hour Service Available

Image of Union Boiler Company 50 years in business ribbon

Our goal is to provide new and existing customers with quality service, installations and repairs, and to assist them with their mechanical needs.

We work to be innovative with new technologies and methods, but always stay rooted in the traditions of our trades and the knowledge and wisdom that comes from over 5 decades of well earned experience.

About Us

Series of pipes and vents in a boiler room

We work diligently to offer quality services by maintaining qualified and experienced personnel. We focus on providing personal and efficient service. We take pride in our employees skillsets, leadership and long standing commitment to you, our valued customers.

Union Boiler Company has benefited from the long tenure of its established and experienced employees as well as the enthusiasm and focus of new crew members. Each member of our staff brings exceptional skills and dedication to the job in order to provide benefits to our customers from their experience in many ways.

We strive to offer timely solutions performed in a personalized, professional manner.

Contact us regarding your mechanical needs and we will gladly assist in finding solutions that our both practical and economical.

Our History

The company was founded in 1966 as Union Boiler Company of Hamilton Ltd. by George Aldighieri. With his leadership and the diligent work of his capable crew, the business grew and maintained success.

As a family business it was carried forward into a second generation by George's son, David Aldighieri. He carried and progressed the business forward with the same work ethic and family values that the company was founded on. Under David's leadership the company continued to succeed and prosper.

Having worked in and serving the industry for many years David sought a partnership with two like minded brothers, Robin Mazzocato and Mike Mazzocato. Sharing the same family oriented values and work ethic, Rob and Mike merged there existing business, Ironstar Industries Inc. with Union Boiler Company of Hamilton Ltd, forming what is now today, UNION BOILER COMPANY LIMITED.

The resulting partnership has resulted in the continued success of the company, built upon the hard work of it's employees, old and new, and leadership focused on maintaining the high level of quality, dedication and service that the company was founded on.


We maintain certifications with the TSSA and the CWB to ensure we are inline with regulations and to ensure the quality our customers expect.

  • mechanical contracting
  • boiler installation and maintenance
  • process piping
  • pipe spooling
  • natural gas line installations and contracting
  • steel fabrication
  • heat exchanger repair and retubing
  • cooling tower replacement
  • hvac
  • combustion and controls service

Contact Us