Oxidation-Reduction Potential in Cooling Tower Efficiency

Cooling Tower Start-Up Season: Don’t Make These Costly Spring Mistakes

Reading Time | 15 Minutes

It’s the end of February, which means one thing in our world. Cooling tower season is coming back. 

Right now, your tower might still be quiet. Maybe it’s been sitting idle all winter. Maybe it was drained and laid up. Maybe it’s just been running minimally in the background. 

But in a few short weeks, when temperatures climb and production ramps up, that system is going to matter again. A lot. 

And every spring, we see the same pattern: facilities flip the switch, assume everything is fine, and then by May they’re dealing with corrosion issuesmicrobiological growth, scaling, or emergency service calls. 

The good news? Most of it is preventable. 

Here are some of the biggest start-up mistakes we see — and what we’ve learned over the years about avoiding them. 

Don’t Wait Until It’s 90 Degrees

Make sure your cooling tower is inspected, cleaned, and chemically balanced before peak demand hits.

cooling tower

Mistake #1: Treating Start-Up Like a Light Switch 

One of the most common assumptions is that if the tower ran fine last season, it’ll run fine this season. 

But a cooling tower isn’t a light fixture. It’s a living, breathing water system. And water systems change over time — especially when they sit. 

Over the winter, you can get: 

  • Sediment settling in the basin 
  • Biofilm development 
  • Corrosion progression 
  • Degraded chemical residuals 
  • Stagnant water conditions 

Even if everything looked good in October, March is a different story. 

What we’ve learned: Start-up should be treated like a reset, not a restart. Inspect, verify, confirm — don’t assume. 

Mistake #2: Skipping a Physical Inspection 

You’d be surprised how often we open towers in the spring and find: 

  • Inches of sludge in the basin 
  • Plugged strainers 
  • Damaged drift eliminators 
  • Corrosion that went unnoticed 
  • Debris from winter storms 

If no one physically looks inside the tower before start-up, you’re operating blind. 

And sludge isn’t just ugly — it’s fuel. It feeds microbiological growth, reduces heat transfer efficiency, and increases chemical demand. 

What we’ve learned: A visual inspection tells you more in 15 minutes than weeks of guessing later. 

Mistake #3: Ignoring Water Chemistry Until There’s a Problem 

Another pattern we see: the tower gets turned on, but chemistry doesn’t get attention until scaling or corrosion shows up. 

That’s backwards. 

The first days and weeks of operation are critical. That’s when: 

  • Biofilm can establish quickly 
  • Corrosion rates can spike 
  • Scale can begin forming 
  • Controllers may not be calibrated correctly 

If conductivity controllers weren’t checked… 
If feed systems weren’t verified… 
If sensors drifted over winter… 

You may not be feeding what you think you’re feeding. 

What we’ve learned: Early chemistry control prevents mid-season emergencies. 

Start the Season Proactive — Not Reactive

Avoid scale, corrosion, and microbiological surprises with a verified start-up plan.

cooling tower workers in hazard gear

Mistake #4: Underestimating Microbiological Risk 

Spring start-up is one of the highest-risk periods for microbiological growth — especially if the system has had stagnant water. 

Warmer temperatures + nutrients + surfaces = rapid growth potential. 

Cooling towers are powerful pieces of equipment. They move large volumes of air and water. That’s why microbiological control isn’t just about efficiency — it’s about safety. 

We’ve seen facilities focus heavily on scale and corrosion while overlooking biological control until a test result forces attention. 

What we’ve learned: Microbiological management isn’t optional at start-up. It’s foundational. 

Mistake #5: Forgetting That Small Problems Compound Fast 

A slightly fouled heat exchanger.  A little extra scale. A mild corrosion issue. A bit more blowdown than normal. Individually, these seem manageable. 

But together, they increase: 

  • Energy costs 
  • Water usage 
  • Chemical consumption 
  • Equipment wear 
  • Risk exposure 

Cooling towers operate continuously once the season is in full swing. Small inefficiencies multiply quickly. 

What we’ve learned: Spring is the cheapest time to correct issues. Summer is the most expensive. 

Mistake #6: Waiting Until It’s 90 Degrees 

This one might be the most common of all. 

We get calls in late May or June that start with: 

“We just turned the tower on and…” 

By then: 

  • Production is active 
  • Occupants are relying on cooling 
  • Downtime isn’t acceptable 
  • Pressure is high 

That’s not the time to troubleshoot. 

The end of winter is the window. It’s the calm before the storm — and it’s the smartest time to evaluate, inspect, clean, and confirm your treatment program is dialed in. 

What we’ve learned: Preventative attention now avoids reactive chaos later. 

What a Strong Start-Up Season Actually Looks Like 

After years of working with cooling towers across industries, here’s what consistently leads to smooth seasons: 

  • A real physical inspection before operation 
  • Cleaning when needed — not just hoping it’s fine 
  • Verifying chemical feed systems and controls 
  • Confirming proper water chemistry targets 
  • Establishing microbiological control early 
  • Reviewing last year’s data and adjusting proactively 

It’s not complicated — but it does require intention. 

Cooling towers don’t fail dramatically all at once. They decline gradually when small details are ignored. Start-up season is your opportunity to reset those details. 

A Final Thought 

The worst time to think about cooling tower maintenance is when it’s already hot, production is on the line, and people are asking why the system isn’t performing the way it should. 

Right now — at the end of February — you have leverage. You have time. You have options. 

A thoughtful start-up sets the tone for the entire season. 

At ChemREADY, we’ve seen what happens when systems are rushed back online without proper evaluation. We’ve also seen how smooth an entire summer can be when start-up is handled correctly from day one. 

If you’re getting ready to bring your cooling tower back online, this is the moment to make sure it’s truly ready. 

Make Sure Your Cooling Tower Is Truly Ready

Let ChemREADY assess your system, confirm your chemistry, and set you up for a smooth season.

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