42-24194-01 - -0.35 WC 2 Stage High Pressure Switch AssemblyRheem 42 24194 01 0. 35 WC 2 Stage High Pressure Switch Assembly The pressure switch is a protective device that opens and causes the HVAC system to stop operating under certain conditions which may be harmful. It is important to note that when a pressure switch is replaced, it is replaced with the exact switch. The pressure settings are very delicate and any change in the setting by installing a different switch could cause a safety issue. Features