- Babcock Mechanical
- Bayes, Inc.
- Beamont Heating & Cooling
- Campbell, Inc.
- Coyle Mechanical, Inc.
- Dimech Services, Inc.
- Dunbar Mechanical, Inc.
- Earl Mechanical Services
- GEM Industrial, Inc.
- Henson Plumbing & Heating, Inc.
- Imperial Plumbing & Heating
- Industrial Power Systems, Inc.
- Jim Wing Plumbing, Co.
- Laroy Plumbing & Heating
- Marlin White & Sons, Inc.
- Merit Plumbing
- Mondo Mechanical, Inc.
- Ott Plumbing, Inc.
- Perrysburg Plumbing, Heating & A/C
- Peters, George F. & Son, Inc.
- Positive Trades Group, LLC
- R. A. Rush Plumbing
- Roth Plumbing
- Titan Mechanical
- Warner Mechanical Corporation
- Wilkes & Co., Inc.
- Beamont Heating & Cooling
- Campbell, Inc.
- Coleman Systems
- Commercial Comfort Systems
- Complete Refrigeration LLC
- Coyle Mechanical, Inc.
- Cross Heating & Cooling, Inc
- Daikin Applied Americas, Inc.
- Dimech Services, Inc.
- Dunbar Mechanical, Inc.
- Earl Mechanical Services
- GEM Industrial, Inc.
- George F. Peters & Sons, Inc.
- Henson Plumbing & Heating, Inc.
- Hoffman & Harpst
- Honeywell, Inc.
- Imperial Plumbing & Heating
- Industrial Power Sytems, Inc.
- J L Mechanical Services, Inc.
- Johnson Controls, Inc.
- Mondo Mechanical, Inc.
- Noron, Inc.
- Perrysburg Plumbing, Heating & A/C
- Peters, George F. & Son, Inc.
- Positive Trades Group, LLC
- Smith-Boughan
- Thompson Plumbing & Heating
- Trane (Toledo Office)
- W J O’Neil Co., Inc.
- Wadsworth Service Inc.
- Wagner-Meinert, Inc.
- Beamont Heating & Cooling
- Campbell, Inc
- Carrier Inc
- Coleman Systems
- Campbell Inc.
- Commercial Comfort Systems
- Complete Refrigeration LLC
- Cross Heating & Cooling, Inc
- Daikin Applied Americas, Inc.
- Dimech Services, Inc.
- Dunbar Mechanical, Inc.
- Dimech Services Inc.
- Earl Mechanical Services
- GEM Industrial, Inc.
- Adaptable Control Solutions
- Hoffman & Harpst
- Honeywell, Inc.
- J L Mechanical Services, Inc.
- Johnson Controls, Inc.
- Noron, Inc.
- Positive Trades Group, LLC
- Refrigeration Mechanics, Inc.
- Positive Trades Group LLC
- Strause Refrigeration, Inc.
- Trane (Toledo Office)
- W J O’Neil Co., Inc.
- Wadsworth Service Inc.