The CTC-1621 is a 2-pipe pneumatic thermostat

Factory-calibrated to normally closed (NC) specifications

which will prevent the 24V control circuit from functioning correctly

Common Questions: Can this be used for back-siphonage backflow prevention

this component provides a direct-fit solution that eliminates field modification risks

Nordyne M0079102 Reversing Valve Els PW 17895 The CTC-1621 is a 2-pipeThe Nordyne M0079102 Reversing Valve with Coil is a precision engineered OEM HVAC replacement part designed for high performance heat pump applications. This 4 way reversing valve is critical for managing refrigerant flow control, allowing your Nordyne unit to switch between heating and cooling cycles with minimal pressure drop. Engineered as a factory authorized component, the M0079102 ensures total compatibility with the original system footprint,