COOLING TOWER | Preventative Maintenance Inspections

A building owner should ensure a regular daily/weekly and monthly preventative maintenance schedule is applied for their cooling towers and ancillary equipment throughout the year to help and ensure:

• The risk of Legionella is managed/reduced
• Scale and debris build-up is managed
• The efficiency of the tower is maintained
• Minimizing early failure of mechanical components/electrical components 
• Reducing corrosion within the tower and on the external surfaces
• Reduction in downtime of the tower
• Longevity of its intended operational life

How long do cooling towers last?

15 to 20 years is the general expectation of life for an industrial cooling tower, used in a cooling process for general office buildings, etc, before the need for replacement or extensive rebuild.

This is why a good preventative maintenance regime is extremely important, as this can sometimes extend the operational life.

We have seen cooling towers that are much older than this.

How often should cooling towers be inspected?

For preventative maintenance and depending on the component, they should be inspected daily, monthly, quarterly, semi-annually, yearly. See below.

Documentation usually required to conduct the works

The following documentation would usually be a requirement prior to any works taking place to ensure it is conducted safely and correctly:

• Previous inspection reports
• System schematics and layout drawings
• Check sheets for recording the works
• Risk assessment
• PPE assessment
• Method statement
• COSHH assessment 
• Work permits etc

Cooling Tower Maintenance Checklist and Plan

Only Engineers and Operatives who are qualified, experienced, and fully understand the design and operation of the system should complete these inspections.

Below we run through an example of the checks that would generally be conducted, any observations should be noted, advice on the needs of the remedial work and, when completed signed off. The urgency of the remedial works will depend on the criticality of any observations.

Please note: Preventative Maintenance should not be confused with Inspecting and Cleaning of Cooling Towers which can be read about in our article 'Overview | Inspecting & Cleaning Cooling Towers'.

What to check daily

• Unusual noise and vibrations in and around the tower, will generally be from the fan
• Unusual noise and vibrations at the condenser water pump
• Check the water level in the basin, this can be done via the level sensor at the BMS if part of the system
• Water quality checks

What to check monthly

• General overview of system condition inspection
• The general condition of the fan and motor/drive mechanism
• Check for oil leaks in components, hoses and fittings
• Check oil levels and add if required
• Clean the fan motor
• The water makeup valve is operating correctly
• Inspect and clean the air inlet
• Inspect and clean the tower drift eliminators
• Inspect and clean the tower fill pack
• Inspect and clean the hot water basin feeding the fill pack
• Inspect and clean the spray nozzles
• Check the spray pattern of the nozzles
• Inspect and clean the tower basin
• Check operation of the blowdown system
• Check operation of the bleed water valve and system
• Check operation of vibration switch
• Check and clean side stream filtration/sweeper systems
• Check operation of the chemical dosing system
• Check and clean pipework strainers
• Manually check the level and valve of the tower water basin and make adjustments if required to the water feed
• Check protective finishes to surfaces of tower and components to ensure are not damaged and compromised
• Review operation of basin heater and clean sensor if necessary
• Check the status of system operation [set to automatic]

 What to check quarterly [3 months]

• Check belt alignment and tightness [if fitted to motor]
• Check fan blades for cracks, missing balancing weights, and any apparent vibrations
• Check fan blade pitch [angle]
• Check fan blade tip clearance
• Review operation/signal of level sensors and clean if necessary 
• Inspect condition of ladders/handrails/stairways/walkways etc

What to check semi-annually [every 6 months]

• Change oil
• Check and tighten fan blade hub

What to check Yearly

• Check all mounting bolts for tightness and signs of corrosion
• Inspect all parts of the motor including oil plugs etc
• Lubricate components
• Inspect drive shaft not loose
• Check for drive shaft/bush wear and tear
• Check motor alignment on the fan

After any Extended Shutdown Checks

• Complete all checks above

Cooling Tower Preventative Maintenance Sample Checklist [PDF] & [.doc]

To download the below document [Free] in A4-[.doc], click the below button to be taken to our shop:

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