Cooling Tower Maintenance Guide
1. Daily/Operational Maintenance
Visual Inspections
- Check for unusual noises/vibrations from fan motors and gearboxes
- Inspect for visible leaks in basin, piping, and valves
- Observe water distribution – look for dry areas on fill
- Check basin water level – ensure automatic makeup valve is working
- Monitor drift – excessive misting indicates problems
Water Treatment Monitoring
- Test and record key parameters:
- pH level (typically 6.5-9.0 range)
- Conductivity/TDS (control cycles of concentration)
- Biocide residual levels
- Inhibitor concentrations
- Check chemical feed systems – pumps, tanks, and injection points
2. Weekly Maintenance Tasks
Water System Checks
- Clean suction strainers and inlet screens
- Check automatic blowdown controller operation
- Inspect float valves and level controls
- Test bleed-off solenoid valves
- Remove surface debris from basin (leaves, dust, etc.)
Mechanical Inspections
- Check fan and motor bearings for overheating
- Inspect V-belt drives for tension and wear (if applicable)
- Monitor vibration levels on rotating equipment
- Check oil levels in gear reducers
3. Monthly Maintenance
Distribution System
- Clean spray nozzles/orifices – remove scale and debris
- Ensure distribution pans are level (counterflow towers)
- Check rotating assembly on crossflow towers:
- Inspect distribution arms for proper rotation
- Clean small orifice holes
- Check bearing condition and seals
- Verify even water distribution across entire fill area
Structural Components
- Inspect drift eliminators for damage and clogging
- Check fill material for visible fouling or deterioration
- Inspect access doors and panels for proper sealing
- Check louvers for damage and cleanliness
4. Seasonal/Quarterly Maintenance
Thorough Cleaning
- Power wash fill material to remove scale and biofilm
- Clean drift eliminators – high pressure wash from air exit side
- Drain and clean cold water basin:
- Remove silt, scale, and debris
- Inspect for corrosion
- Apply corrosion inhibitor after cleaning
- Clean tower structure interior surfaces
Mechanical Detailed Inspection
- Check motor alignment and coupling condition
- Lubricate bearings per manufacturer specifications
- Inspect fan blades for cracks, corrosion, or imbalance
- Test safety devices – vibration switches, freeze stats
- Calibrate all controls – temperature, level, conductivity
5. Semi-Annual/Annual Maintenance
Major Mechanical Service
- Replace V-belts (if worn or annually as preventive measure)
- Change gearbox oil and analyze for wear metals
- Megger test motors for winding insulation integrity
- Balance fan assembly if vibration indicates need
- Inspect/replace shaft seals and bearings
- Check/replace motor brushes on wound rotor motors
Structural Integrity
- Complete inspection of tower structure:
- Check wooden members for decay (wooden towers)
- Inspect metal components for corrosion
- Examine FRP surfaces for cracks or delamination
- Test cathodic protection system (if installed)
- Inspect and repair coatings/paint
- Check anchor bolts and structural connections
6. Water Treatment Program Maintenance
Chemical System Maintenance
- Clean chemical injection lines monthly
- Calibrate chemical feed pumps quarterly
- Inspect chemical storage tanks for leaks/contamination
- Verify proper mixing of chemicals
- Maintain accurate inventory of treatment chemicals
Monitoring Optimization
- Calibrate test instruments and controllers
- Review treatment program effectiveness with vendor
- Adjust cycles of concentration for optimal water/energy use
- Implement seasonal adjustments for temperature changes
7. Winterization (Cold Climate Specific)
Freeze Protection Measures
- Install freeze protection thermostats
- Implement basin heaters or heat tracing on critical pipes
- Adjust fan cycling for freeze prevention
- Consider automatic winterization valves
- Increase heat load if possible during extreme cold
Winter Operation Adjustments
- Modify water treatment for cold temperature chemistry
- Increase blowdown if using glycol solutions
- Install temporary enclosures for extreme conditions
- Implement remote monitoring for unattended sites
8. Record Keeping & Documentation
Essential Maintenance Records
- Daily log sheets (temperature, pressure, chemical levels)
- Maintenance work orders and repair history
- Water treatment reports and chemical usage
- Parts replacement log with dates and reasons
- Energy consumption records for performance trending
Compliance Documentation
- Legionella testing records (as required by local regulations)
- Wastewater discharge reports for blowdown
- Safety inspection certificates
- Manufacturer service bulletins and updates
9. Specialized Maintenance Procedures
Fill Replacement
- Inspect fill annually for deterioration
- Replace in sections if damage exceeds 20%
- Consider upgrade to more efficient fill design
- Ensure proper spacing and support during installation
Drift Eliminator Replacement
- Replace if damage affects efficiency >5%
- Consider upgrading to high-efficiency models
- Ensure proper sealing at edges and supports
Fan Deck Repair
- Repair cracks and delamination promptly
- Maintain proper slope for drainage
- Seal penetrations to prevent air bypass
10. Safety-First Maintenance Protocol
Pre-Work Procedures
- Lock Out/Tag Out all energy sources
- Test atmosphere in confined spaces
- Install fall protection for elevated work
- Use chemical PPE when handling treatment chemicals
- Establish communication for isolated workers
Legionella Risk Management
- Regular testing for legionella bacteria
- Shock treatment protocol for positive results
- Maintain proper biocide levels continuously
- Document all bacteriological testing
Maintenance Schedule Summary
| Frequency | Key Tasks |
| Daily | Visual inspection, water testing, chemical feed check |
| Weekly | Strainer cleaning, debris removal, operational checks |
| Monthly | Nozzle cleaning, distribution check, belt tension |
| Quarterly | Fill cleaning, basin cleaning, lubrication |
| Semi-Annual | Gearbox service, structural inspection, calibration |
| Annual | Major component overhaul, fill inspection, motor testing |
| As Needed | Repairs, component replacement, upgrades |
Performance Indicators for Maintenance Success
- Approach temperature (stable at design conditions)
- Range temperature (consistent with heat load)
- Energy consumption (no unexplained increases)
- Water consumption (within expected cycles of concentration)
- Chemical consumption (consistent with water volume)
Pro Tip: Implement a Computerized Maintenance Management System (CMMS) to track schedules, work orders, inventory, and performance trends. This transforms reactive maintenance into proactive reliability-centered maintenance, extending equipment life by 30-50% and reducing emergency repairs by up to 75%.