When replacing older Erie zone valve motors

specifically frequently appearing in AE4-1392 series configurations requiring a 1-1/8" sweat discharge

and other 1k ohm PTC-compatible digital electronic controllers

this is the official replacement limit switch for several generations of the Defender series

Trane CNT4991 Pressure Switch R-410A When replacing older Erie zoneThe Trane CNT4991 is a 10 inch SPST pressure switch engineered for precise atmospheric monitoring in high efficiency Trane and American Standard HVAC systems. This OEM air pressure switch features a single pole single throw (SPST) contact configuration, rated at 0. 1" WC (water column) for low pressure detection. It is designed to interrupt or complete the 24V control circuit (rated at 28 VA) when specific airflow or flue gas pressure thresholds are