When you're servicing commercial rooftop units or residential air handlers that require a reliable 24V control circuit

Proper integration with the Q90-75 boiler series is essential for maintaining the pressure differential profile required by the ignition control board

Whether you are troubleshooting air filtration status or ensuring proper draft in gas-fired units

allowing technicians to restore system performance to factory specifications while ensuring safe operation of the residential heating system

the Robertshaw 5500-136 utilizes 8-32 UNC mounting threads and includes a universal break-off shaft to match varying dial depths

Eaton Cutler-Hammer C320KGS21 Auxiliary Contact 319852-301 When you're servicing commercial rooftopThe Eaton Cutler Hammer C320KGS21 is a side mounted auxiliary contact block designed for heavy duty switching applications. This unit features a 1NC (Normally Closed) configuration, providing reliable feedback for control circuits and interlocking logic. Engineered for versatility, the C320KGS21 is compatible with Freedom Series starters and contactors spanning NEMA Sizes 3 5 and IEC Sizes L S. It is also the standard solution for Definite Purpose