What reading would indicate that the pressure switch is functioning correctly?

When evaluating the functionality of a pressure switch in an HVAC system, a closed reading indicates that the switch is functioning correctly. A closed pressure switch means that it is allowing current to flow through, which signifies that it is detecting the appropriate pressure level within the system. This is essential for the operation of components such as the blower motor or the burner.

If the pressure switch reads closed, it confirms that the system is under the right conditions to operate safely and effectively. This is critical for ensuring that the HVAC system runs efficiently, as the pressure switch prevents the system from starting if conditions are not favorable, such as low pressure conditions which could lead to equipment damage or unsafe operation.

An open reading would suggest that the switch is either not detecting sufficient pressure or that there may be an issue within the system, leading to a shutdown of the system to avoid malfunction. Similarly, a partially closed state would indicate a potential fault where the switch is not fully operating as intended. Bypassing the switch is a significant safety concern, as it disables the protective function designed to ensure that the equipment operates under safe pressure conditions.