Lochinvar & A.O. Smith 100109908 Flame Sensor 320819-301 The Over-Pressure Protection Device (OPD)

The Over-Pressure Protection Device (OPD) is a safety mechanism required for regulators used on piping systems with inlet pressures exceeding 2 PSI (up to 5 PSI) to protect downstream equipment in the event of a regulator failure

the 110851 is calibrated with a natural gas pilot orifice

This 2C configuration is ideal for technicians looking to optimize HVAC system efficiency in cold-weather applications where low ambient temperatures threaten internal lubrication

For systems requiring the valve to close on temperature rise

though it is typically factory-configured for Natural Gas

Lochinvar & A.O. Smith 100109908 Flame Sensor 320819-301 The Over-Pressure Protection Device (OPD)The Lochinvar & A. O. Smith 100109908 Flame Sensor is a critical OEM replacement part designed for precise flame rectification in high efficiency water heaters and boilers. As a seasoned tech, you know that a failing flame sensor rod is the primary culprit behind intermittent data signals and "no flame detected" lockouts. This genuine factory part (formerly identified as part number 9004520215) ensures the flame sensing circuit maintains the microamp