The center port of the manifold is typically what color?

The center port of the manifold is typically associated with the yellow hose because it is used for refrigerant recovery, charging, or vacuuming in HVAC systems. This yellow port is designed for service tasks that involve the transfer of refrigerant, making it distinct from the other ports, which are usually designated for specific pressure readings.

The blue and red hoses are recognized for low-pressure and high-pressure readings, respectively; blue is for the low side, and red is for the high side of the system. The green hose is generally not used in standard HVAC manifold setups, which further reinforces the significance of the yellow hose as the correct answer for operations involving recovery or charging.