As a professional-grade low voltage thermostat

you should adjust the air pressure to match your boiler fill valve setting (typically 12–15 PSI) while the tank is empty or isolated from system pressure

This control is a close on rise (normally open) device

" If the inducer motor is running but the ignition sequence fails

Ranco V1-408060-170 Reversing Valve 30067439-890 As a professional-grade low voltageThe Ranco V1 408060 170 Reversing Valve is a technical essential for technicians servicing residential and light commercial heat pump systems, including window units, unitary, and split systems. This 4 way reversing valve operates under the full pressure of the heat pump system, utilizing a 4 way pilot valve to provide positive reversals even at low pressure differentials. Engineered for precision, it features a 1 2" suction connection and a 3 8"