Cooling Tower Maintenance Guide

Daily Checks

• Check water level in the basin — top up if low. Verify the make-up water valve is operating correctly.
• Check the biocide dosing system — verify it's dosing and the chemical levels are adequate.
• Check conductivity controller — verify it's maintaining TDS within the set range and operating the blowdown valve.
• Check for unusual noise or vibration from the fan and motor.
• Inspect the drift eliminators for damage or blockage.
• Check the water distribution system — verify all nozzles are spraying evenly.
• Record water treatment chemical consumption.

Weekly Tasks

• Test water for pH, conductivity, and biocide residual — adjust treatment as needed.
• Check the fan bearings for noise and temperature.
• Inspect the fan belt for tension and condition (belt-driven towers).
• Check the motor amperage — compare to nameplate FLA.
• Inspect the fill media for scaling, biofouling, or damage.
• Clean the basin strainer.
• Check for air leaks in the fan housing and water distribution system.

Monthly Tasks

• Microbiological testing — Heterotrophic Colony Count (HCC). Target: below 10,000 CFU/mL.
• Legionella testing (quarterly minimum, monthly for high-risk sites).
• Inspect and clean the water distribution nozzles — remove blockages.
• Check the structure for corrosion — especially on steel towers.
• Inspect the fan hub and blades for cracks or erosion.
• Lubricate fan bearings and motor bearings (if not sealed).
• Check the make-up water valve and float valve for correct operation.
• Record and trend water treatment data.

Annual Maintenance

1. Drain and clean: Drain the entire system. Physically clean the basin, fill media, drift eliminators, and water distribution system. Remove all sediment, biofilm, and scale.
2. Disinfect: Hyperchlorinate the system with 5–10 ppm free chlorine for 4–8 hours, then flush.
3. Inspect the fill: Check for degradation, scaling, and biofouling. Replace damaged fill sections.
4. Inspect the drift eliminators: Replace if damaged or excessively scaled. Damaged eliminators increase drift and Legionella risk.
5. Service the fan and motor: Check bearings, belts, alignment, and balance. Replace worn components.
6. Inspect the structure: Check for corrosion, loose fasteners, and structural integrity. Paint or treat corrosion on steel towers.
7. Calibrate sensors: Calibrate the conductivity sensor, pH sensor, and biocide dosing system.
8. Review the water treatment programme: Adjust chemical dosing rates based on the year's operating data.

Key Performance Indicators