Common Questions Is the DP140005U21D suitable for outdoor installations

Equipped with a nitrile seal material

causing the system to trip on high-limit or flame-sensing errors

Engineered for immediate data acquisition

The assembly weighs approximately 28 lbs and measures roughly 22

Lochinvar & A.O. Smith 100109951 Pressure Switch 322057-301 Common Questions Is the DP140005U21DWhen you are troubleshooting a pressure switch failure on a high efficiency hydronic system, the Lochinvar & A. O. Smith 100109951 is the specific OEM replacement part required to restore precise combustion air pressure monitoring. This air pressure switch is factory calibrated for the BTN 200 366 series water heaters and boilers, ensuring that the blower is moving sufficient air for safe ignition. As a normally open (NO) switch with a set point of 2.