What kind of deficiencies do you commonly in these when inspecting cooling towers

I have a fair number of things identified now but I’m still curious about common problems found with:

  • Pumps: circulation and spray
  • Chiller tubes
  • Water pipes and valves
  • Basin balance piping with multiple units

Anything that is very common, please mention!
Here’s a photo of my menu for cooling towers. Sorry about the quality, click it for a clearer view. Feel free to comment.