What color hose on the manifold indicates low pressure measurement?

The blue hose on a manifold gauge set is designated for low-pressure measurement. This is consistent across most HVAC systems. The blue hose connects to the low-pressure service port of the refrigeration system, allowing technicians to measure and record the low side pressures during troubleshooting or service tasks.

Understanding the color coding is essential for safely and accurately diagnosing refrigerant systems. Each hose color serves a specific purpose, with blue indicating low pressure, which helps prevent confusion during operation and ensures the technician uses the correct hose for measuring pressures.

The other hoses serve different functions: the red hose typically connects to the high-pressure side, while the yellow hose is often used for refrigerant recovery or charging. Thus, recognizing the blue hose as the one associated with low pressure is key in the context of HVAC service.