About

R.J. O’Neil, Inc. is a Mechanical Contractor servicing the Greater Chicagoland Area. Established in 1926, we have decades of experience in HVAC-R, Plumbing, and Pipefitting. We specialize in maintenance, service, and installation across a variety of industries. We build relationships with the people driving your success: you, fellow tradespeople, our team, and our subcontractors.