though mounting in an upright position is recommended for maximum accuracy

This OEM Lennox part is a manual reset

ensuring the SPST switch cycles efficiently based on real-time evaporator temperature

eliminating the need to drain the system or break pipe connections

Precision Orifice: Factory-calibrated for natural gas to provide stable flame characteristics and reliable sensor feedback

Johnson Controls A19AHA-6 Utility Thermostat Els PW 17895 though mounting in an uprightUtility Thermostat, 120 208 240 Vac, 20 100 Degree Temperature Range, 3 12 Adjustable Differential, 6' Capillary Length, Remote Bulb, Automatic Reset, No Enclosure