background

Professional, Cost-Effective Control Systems Solutions

Since 1985, we have built a first class reputation
based on quick response and professionalism.

View Testimonials
Union HVAC

A Union Mechanical Contractor Provider

Korellis Systems Control is a union mechanical contractor serving many school districts, churches and other commercial buildings in and around Chicagoland.

Since 1985, we have built a first class reputation based on quick response, professionalism, and honest, hardworking, respectful service. Our customers know that we have the expertise, experience and knowledge to get them up and running with the simplest, most affordable solutions.

In over 20 years of business, we have never had a school or church close because they had no heat.

  • “Korellis Systems is focused on customer service and has made consistent timely decisions and recommendations that provide economical solutions to our HVAC service needs.”
    Thomas DeHart FMA
    Director of Facilities Services K-8 Schools
  • “Your staff arrived promptly, diagnosed the problem, and
    replaced a failed refrigeration compressor with a minimum amount of down time and disruption to our Kitchen operation.”
    Dale E. Jonas
    Director of Maintenance - Steger School District #194
  • “Their response and solution-driven professionalism makes my job easier. And they always find the most cost-efficient resolution to our problems.”
    Bob Verisario
    Director of Buildings and Grounds Glenbard District 87