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Cooling Maintenance

Cooling Tower Maintenance Checklist

Control legionella risk and maintain cooling performance with structured cooling tower checks — water treatment, fill pack condition, drift eliminators, and HSE L8 compliance.

What is a cooling tower maintenance checklist?

A cooling tower maintenance checklist is a structured list of the 12 preventive maintenance tasks — covering visual, functional, cleaning, safety and record-keeping checks — that keep a cooling tower running safely and reliably. It groups routine checks by frequency, from daily inspections to annual servicing, so FM teams and building engineers can plan and evidence preventive maintenance.

Core cooling tower checks

  • Inspect drift eliminators for damage or displacement
  • Check water treatment chemical dosing levels and biocide residuals
  • Check basin/sump for sludge, debris, and biological growth
  • Verify legionella control measures are in place and documented
  • Record water temperatures, chemical levels, and microbiological test results

What is a cooling tower?

A cooling tower rejects heat from a building's cooling system to the atmosphere through evaporative cooling. Warm condenser water from the chiller is distributed over a fill pack while a fan draws ambient air through the tower, cooling the water through evaporation. Cooling towers require rigorous maintenance due to their legionella risk profile and are subject to statutory water hygiene controls.

Typical Cooling tower maintenance checklist

A practical starting point for planned preventive maintenance. Always refer to the manufacturer's O&M manual and site-specific requirements.

Visual Checks

  • Inspect drift eliminators for damage or displacement
  • Check fill pack condition for fouling, scaling, or biological growth
  • Inspect water distribution nozzles or troughs for blockages
  • Inspect casing and structural supports for corrosion or deterioration

Functional Checks

  • Check water treatment chemical dosing levels and biocide residuals
  • Test cooling tower water temperature and approach to wet bulb
  • Inspect fan blades, bearings, and motor condition
  • Check make-up water float valve and overflow

Cleaning & Housekeeping

  • Check basin/sump for sludge, debris, and biological growth
  • Clean strainer baskets and bleed-off valves

Safety Checks

  • Verify legionella control measures are in place and documented

Record Keeping

  • Record water temperatures, chemical levels, and microbiological test results

Typical maintenance frequency

Suggested intervals for cooling tower maintenance. Actual frequencies should follow manufacturer guidance and site-specific risk assessments.

Weekly

  • Check chemical dosing levels
  • Visual inspection for cleanliness
  • Record water temperatures

Monthly

  • Microbiological water sampling
  • Clean strainers and sump
  • Check drift eliminators

Quarterly

  • Full water system review
  • Fill pack inspection
  • Fan and motor check

Annually

  • Full tower clean and disinfection
  • Fan bearing and motor service
  • Structural inspection
  • Legionella risk assessment review

Common faults and issues

Issues to be aware of when maintaining cooling tower equipment.

Legionella proliferation from inadequate water treatment or stagnant water — a serious public health risk
Scale buildup on fill pack and heat exchanger surfaces reducing cooling performance
Biological growth (algae, biofilm) blocking distribution nozzles and fill pack
Drift eliminator damage allowing aerosol drift, increasing legionella exposure risk
Fan bearing failure from corrosion in the humid tower environment
Corrosion of the basin, casing, or structural supports

Safety and compliance notes

Key safety considerations for cooling tower maintenance. This is general guidance only — always follow OEM instructions, statutory requirements, and your organisation's safe systems of work.

Cooling towers are high-risk assets for legionella — follow HSE ACoP L8 and HSG274 Part 1 guidance
Maintain a comprehensive written water treatment management scheme with competent oversight
Do not enter cooling tower basins without confined space procedures where applicable
Working at height on cooling tower platforms requires appropriate fall protection
Ensure all water treatment activities are documented and auditable
How PM Assist helps

Managing Cooling tower documentation with PM Assist

PM Assist helps FM and building operations teams search their O&M manuals and building drawings in seconds. Upload your cooling tower documentation and ask questions like “What is the rated cooling capacity?” or “When was the last F-Gas leak check?” — and get source-cited answers instantly.

See PM Assist answer questions about a real cooling tower manual — try the live demo, no signup needed.

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Frequently asked questions

Manage your building documentation with AI

PM Assist gives FM teams instant access to O&M manuals, drawings, and maintenance knowledge — all searchable with AI.

  • Upload and organise building documentation
  • AI-powered search across all your manuals
  • Source-cited answers for maintenance queries
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