Trane gag00979 Blue Compound Gauge R-22 R-404A R-410A

Product Description

The TRANE gag00979 is a blue compound refrigerant gauge measuring 3.125 inches in face diameter, designed for use in HVAC refrigeration service work. Compound gauges read both pressure and vacuum on the low-pressure side of a refrigerant circuit, making them a standard tool for system diagnostics, charging, and evacuation procedures. The gag00979 is compatible with R-22, R-404A, and R-410A refrigerants, covering a wide range of residential and light commercial systems currently in service. HVAC technicians rely on this gauge as a direct OEM-sourced replacement or service tool component.

This gauge is suited for low-side manifold service work on split systems, package units, heat pumps, and refrigeration equipment using R-22, R-404A, or R-410A. Its compound scale allows the technician to monitor suction-side pressures during charging and to verify vacuum depth during system evacuation. The blue color follows the industry-standard convention for low-pressure low-side gauges, reducing misidentification risk during fast-paced field service.

Key Features

• Blue compound gauge reads both positive pressure and vacuum on the low side of a refrigerant circuit
• 3.125-inch face diameter for clear field readability
• Scaled for R-22, R-404A, and R-410A refrigerants
• OEM part sourced directly from TRANE for service and replacement applications
• Industry-standard blue color coding for low-pressure side identification

Compatibility

Compatible with R-22, R-404A, and R-410A refrigerant systems. Designed as a low-side compound gauge replacement for manifold gauge sets used in residential and light commercial HVAC and refrigeration service.

Installation Notes

Installation and service of refrigerant-side components must be performed by EPA Section 608 certified HVAC technicians. Before connecting or disconnecting gauge hoses, recover refrigerant per applicable regulations and ensure the manifold service valves are closed. Inspect gauge port fittings for damage or debris before connection to avoid contamination of the refrigerant circuit. Handle the gauge carefully to avoid impact damage to the bourdon tube mechanism, which can affect reading accuracy.