Commercial Chiller Low Flow

Likely causes

These categories help organize the diagnostic process; they are not a remote diagnosis.

• Stopped, damaged, air-bound, misapplied, or incorrectly controlled pump
• Closed valve, dirty strainer, blocked heat exchanger, low system pressure, or piping restriction
• Failed or inaccurate flow switch, differential-pressure sensor, meter, VFD command, or sequence

Safe facility observations

Facility staff may record alarm text, thermostat or BAS display status, affected areas, time of onset, visible water or ice from a safe location, and unusual sound or odor. Do not open energized panels, reset a repeatedly tripping breaker, bypass safeties, force controls, handle refrigerant, work on combustion equipment, or enter pressure systems.

• Record displayed flows, pressures, temperatures, pump status, VFD speed, and valve commands
• Note recent valve, pump, treatment, construction, or control changes
• Do not defeat flow proof or open pressurized piping

Professional diagnostic process

Diagnosis compares required and actual hydraulic conditions, pump performance, differential pressure, valves, strainers, air, system pressure, heat exchangers, sensors, flow proof, controls, and plant configuration.

Equipment commonly involved

The fault can originate in the primary equipment or a connected system.

• Chiller evaporator and condenser
• Primary and secondary pumps
• Valves and strainers
• Flow and pressure sensors

Risks of delay

Low flow can trip equipment, freeze or damage heat exchangers, reduce capacity, destabilize temperature, damage pumps, and interrupt critical cooling.

Repair considerations

Correct the hydraulic, pump, valve, strainer, air, sensor, or sequence issue and verify stable flow across required operating modes.

Replacement considerations

Pump, sensor, valve, heat-exchanger, or plant changes require verified design flow, pump curve, system resistance, controls, redundancy, access, and shutdown planning.

Related maintenance

Trend flow, pressure, temperatures, pump speed and current, strainers, valves, air management, water treatment, sensors, flow proof, and sequence.

Safety notice

This guide is educational and is not a substitute for on-site diagnosis. Follow facility safety procedures and applicable code. If there is smoke, fire, suspected gas, exposed electrical damage, a significant refrigerant release, pressure hazard, or an immediate life-safety concern, evacuate or isolate the area as appropriate and contact emergency or qualified response personnel.