Lochinvar & A.O. Smith 100166238 Switch 328140-751 Visible moisture around the top

Visible moisture around the top of the valve bonnet or resistance during stem travel often indicates that the valve stem seal has degraded and requires a new packing maintenance kit

Key Benefits ASME CSD-1 Compliance: Meets strict regulatory standards for secondary manual reset safety controls on steam and hot water boilers

This switch is calibrated to open or close at specific WC (water column) setpoints

This multi-probe fixture features a rugged cast iron body and a die-cast aluminum terminal housing finished with a chemical-resistant epoxy coating

When troubleshooting a leaking 1/2 inch vacuum breaker

Lochinvar & A.O. Smith 100166238 Switch 328140-751 Visible moisture around the topThe Lochinvar & A. O. Smith 100166238 Gas Pressure Switch is a critical safety component designed for high performance gas fired boilers and commercial water heaters. Featuring a 1 20" WC adjustable range, this manual reset gas pressure switch ensures system integrity by monitoring incoming or manifold gas pressure. If pressures deviate from the calibrated setpoint, the switch initiates a safety lockout, preventing hazardous combustion conditions.