Seven Steps to Proper Cooling Tower Shutdown
Tuesday, September 24, 2019

Seven Steps to Proper Cooling Tower Shutdown

With fall and winter rapidly approaching, it’s time to turn off your cooling systems and prepare for colder temperatures. This process includes shutting down your cooling tower, and making sure you do it correctly.

Proper cooling tower shutdown is imperative for many reasons. First, any untreated water left in your cooling tower will lead to system corrosion and invites bacteria, like Legionella, to grow. This increases your risk for a Legionella outbreak when you restart your system in the spring. Bacterial growth during the off-season can also lead to under deposit and bacterial growth corrosion, thus damaging the cooling tower. In addition, any sediment left in the system can block distribution nozzles and decks during start-up, which can negatively affect your cooling tower’s efficacy and lead to increased downtime. 

Here are seven steps you can follow to properly shut down your cooling tower: 


  1. Two weeks before shutting down the system, increase bleed to flush the tower and remove any suspended materials that have accumulated in the system. Consider removing scale deposits from drift eliminators at this time, too. It’s also important to add additional cooling tower corrosion inhibitor to the system to provide protection during the off-season. 
  2. One week out, add a scale and sludge dispersant to remove accumulated dirt and scale. 
  3. Three days prior, add a biodispersant and biocide to remove biofilm and sanitize the cooling system. 
  4. At shutdown, sweep out the hot water distribution basin if you have a crossflow tower. For counterflow systems, remove the drift eliminators and visually inspect the nozzles while the tower is running to identify any clogs. Clogged nozzles will need cleaning or replacing.

Flush the tower basin and refill to remove remaining dirt and debris and clean all strainers. 

  1. For controller and chemical feed systems, remove chemical pump lines from products and flush the pump by running fresh water through the system. Then, unplug the pumps and allow foot valves to hang free and dry.
  2. Turn off all chemical pumps and be sure to seal all chemical packages for winter storage. Flush the chemical control water lines and inspect the conductivity and pH probes. Clean if necessary. 
  3. Lastly, brush the chiller’s condenser tubes and store without the end bells so air can flow through freely. 

Do you have questions about this process? State’s team of water treatment experts are available to help and provide you with the tools, products and service you need to ensure your cooling tower is in top shape. 

To learn more about State’s cooling tower and water treatment solutions, or be put in contact with your local Account Manager, call (877) 747-6986.