- A.O. Smith
- Acorn
- Amtrol
- Bell & Gossett
- Beacon Morris
- Bock
- Buderus
- B-Vent Pipe & Fittings
- Charter Plastics
- Danfoss
- Duct Wrap
- Easy Heat
- Eemax
- Field Controls
- Hart & Cooley
- Heat-Timer
- Hoffman Specialty
- Honeywell
- Hydrolevel
- Insultarp
- Little Giant
Magic Aire
- Maid-O-Mist
- McDonnell & Miller
- Modine
- Myson
- Pentair Thermal Heat Tape
- Reflectix
- Runtal
- Southwark
- Taco
- Thermostat Wire
- Tjernlund
- Viega
- Watts Radiant
- Webstone
- Weil-McLain
- Z-Vent