Preventive Maintenance Checklist for Water Cooled Package Unit (WCPU)

Protect your investment and ensure year-round reliability with this comprehensive Preventive Maintenance Checklist for Water Cooled Package Units (WCPU) — the essential guide for facility managers, building owners, and HVAC technicians maintaining offices, retail malls, hotels, high-rise towers, and commercial properties.

Daily / Weekly Quick Checks (Operator Level):

• Verify normal operation: cooling output, unusual noises, or vibrations
• Check condensate drain pan for standing water or overflow
• Monitor BMS / control panel for alarms, high-pressure trips, or abnormal temperatures
• Inspect exterior cabinet for leaks, corrosion, or damage

Monthly Preventive Maintenance Tasks:

• Clean / replace air filters (critical in high-traffic retail & office spaces)
• Clean evaporator coil face (remove dust & debris)
• Clear condensate drain line, trap, and pan – add biocide tablet if needed
• Check blower belts (if applicable), tension, and alignment
• Inspect electrical connections for tightness and signs of overheating
• Record condenser water entering/leaving temperatures and pressure drop

Quarterly Critical WCPU Maintenance:

• Clean Y-strainers and side-stream filters on condenser water lines
• Test condenser water quality (pH, conductivity, hardness, inhibitor residuals)
• Verify proper water flow rate (GPM) at each unit – adjust balancing valves
• Clean cooling tower basin, fill, drift eliminators, and louvers
• Inspect & tighten all condenser water piping connections
• Check compressor amp draw and compare to nameplate values

Semi-Annual / Biannual Deep Maintenance:

• Chemically descale or clean water-cooled condenser tubes (frequency depends on water treatment effectiveness)
• Inspect & clean condenser water side of heat exchanger
• Perform superheat / subcooling check and verify refrigerant charge
• Lubricate fan motors, bearings, and other moving parts per manufacturer schedule
• Test & calibrate safety controls (high/low pressure, freeze stat, flow switch)

Annual Professional Service (Recommended by Factory-Trained Technicians):

• Full system performance test (capacity, efficiency, temperature differentials)
• Acid or non-acid tube cleaning if scaling present
• Compressor oil sampling & analysis (screw/scroll models)
• Electrical panel cleaning, contactor inspection, and control board verification
• Update BMS programming, sensor calibration, and trend logging setup
• Comprehensive cooling tower inspection & mechanical service

Pro Tips for Maximum WCPU Longevity: Document every task with dates, readings, and photos. Maintain consistent water treatment — it’s the #1 factor in preventing costly condenser fouling. Schedule major services during low-season or off-peak hours to minimize tenant disruption. Partner with experienced WCPU specialists for high-rise and commercial loop expertise.

Following this preventive maintenance checklist helps Water Cooled Package Units achieve 20–25+ years of dependable service, keeps energy bills low, prevents unexpected breakdowns, ensures excellent indoor comfort, and protects your commercial property’s HVAC investment for the long term.

Implement this checklist today — your building’s efficiency, reliability, and tenant satisfaction depend on it!