Evaporative coolers are awesome. They use less electricity than AC units and excel at cooling in hot, dry climates. But they’re still machines, and machines can have problems from time to time.
Here’s how you can troubleshoot some of the most common issues that arise when people try to use their vaporizable coolers.
Troubleshooting Common Evaporative Cooler Problems
Your Cooler Is Not Blowing Cold Air
We’ve all been there. You crank your cooler on for the first time of the season and… nothing. The air blowing out is warm or barely cool.
The most common cause of this problem is dry cooling pads. Remember those special evaporative cooler pads we talked about? They soak up water and chill air as it blows through them. If they dry out or become clogged with dirt and minerals, the cooler can’t do its job.
Remove the pads and take a look at them. If they appear brown, stiff, or crusty, it’s time for new ones.
Your next stop is the water pump. Water pumps draw water from the reservoir and direct it upwards toward the cooling pads. Without water from the pump, the pads will dry out quickly.
Listen for the pump to prime when you turn on the unit. You should be able to hear water flowing somewhere inside the unit if the pump is working. If you don’t hear it, there could be something preventing water from flowing. Debris often clogs the inlet tube and spray bars. Remove any obvious obstructions and try again.
If the water pump is still silent after flushing out the inlet, it may be broken. You can try reinstalling the pump, but odds are you’ll need to replace it.
Also, make sure your water reservoir is full. If there’s not enough water in the tank, the pump can’t draw up enough to saturate the pads. Fill up the tank and turn on the cooler. If it blows cold immediately, you are just running low on H2O.
Mineral Buildup and Scale Deposits
If you live in a hard water area, scale buildup is the enemy. Minerals in the water form a white or gray crust on the pads, pump, and internal parts of your cooler. Scale buildup reduces airflow and cooling efficiency.
You may notice dry spots or lines on the pads even when the pump is running. Mineral deposits can cause this by preventing water from flowing through the spray bar and tubing evenly.
Combat scale buildup by flushing out the pads and any other removable internal parts with a white vinegar and water solution. Vinegar easily dissolves calcium deposits and other minerals without harming your cooler. For tough buildup, soak the parts for up to 30 minutes.
Installing a water treatment product in your reservoir also helps prevent buildup. There’s little you can do to completely avoid scale, but treating your water makes a difference over time.
Mold, Mildew, & Odors
No one wants to walk into a room smelling like mildew. If your cooler has developed a musty or sour smell, chances are mold or mildew is growing inside of it. Vaporizable coolers naturally create an environment where algae, mold, and bacteria thrive.
The pads and water tanks are moist most of the time. Over time, soil and bacteria can accumulate in your cooler. Once mold and mildew build up, they can cause odors and even trigger allergies or breathing problems.
Drain the entire water tank and give it a good cleaning with soap and warm water. Do the same for your pads. After cleaning the pads, let them dry out completely before reinstalling them.
Make sure to look over the inside of the reservoir for slime or discoloration. Scour the tank until it’s clean and odor-free.
Finally, the easiest way to prevent mold growth is to regularly drain and refill the water tank. Try to drain the tank at least once a week during the cooling season. Don’t let water sit in your cooler for multiple days in a row if you can avoid it.
Weak Airflow
Running your cooler but getting little air movement? Low air pressure is another frustrating issue that has relatively simple solutions.
Again, check your evaporative cooler pads. If the pads are dry or full of dirt and debris, they can’t draw in enough air. Either clean your pads or replace them.
While you’re troubleshooting, check supply vents and ducts that connect to your cooler. vents and ducts for kinks or clogs. Blocking or covering air vents with furniture or drapes also reduces airflow.
You should also examine the fan itself. How quickly do the fan blades spin? Slow air flow can be the result of stuck fan blades. Dirt and debris accumulate on fan blades and can slow them down. Remove anything caught in the blades and wipe them down with a damp cloth.
Leaks
Water pooling around your unit is never a good sign. Fortunately, leaks aren’t too difficult to track down. First, check your float valve. The float valve controls water flow into the reservoir.
If the valve is stuck in the open position or broken, water will constantly pour into the tank. Adjusting or replacing the float valve should stop the leak.
Leaks can also occur when water lines become cracked or damaged. Trace your water lines and check all hoses and connections for leaks. Hose damage is one of the easiest issues to fix. Simply replace the leaking hose before the problem gets worse.
Your Cooler Doesn’t Cool on Humid Days
This is not a problem with your cooler. It’s just the way evaporative coolers operate. A cooler works by putting moisture into the air.
When humidity levels are high, evaporative coolers can’t do their job. There’s only so much moisture the air can hold. On humid days, it might be best to simply turn off the cooling feature on your unit. At least you’ll still have a fan to keep air circulating.
Do I Need to Regularly Service My Cooler?
Well, yeah… kind of? Drain the tank and clean your cooler before and after each cooling season. Monthly maintenance is ideal, but at the very least, do these things once a week when you use it.
Just like your car, periodic checkups and lubrication keep your cooler running smoothly and prevent larger issues from cropping up. Replace your cooling pads every season or two, depending on how often you use your cooler and how hard your water is.
The hardest part about maintaining your evaporative cooler is remembering to do it. Set a weekly reminder on your phone or leave notes around your house. Staying on top of maintenance will ensure you are always cool and worry-free.
Customer Case Study: Weak Airflow & Water Leaks In An Evaporative Cooler
Location: Cape Town, Western Cape, South Africa
Building: 2-bedroom apartment (unit was approximately ±75m²)
Cooler type: Window-mounted model
Issue:
I received a call from a customer who stated that her evaporative cooler was turned on, but there was barely any airflow coming from it. When she called me, water began leaking from the bottom of the unit onto the floor.
Symptoms:
Weak airflow even when the cooler was on
Water leaks onto the property, causing damage to the walls/floor
Inspection:
Upon closer inspection, I found that;
- The cooler’s fan and air vents were blocked by dust, and furniture was placed too closely around the unit
- The float valve was faulty, which caused water to constantly flow into the tank, resulting in leaks.
Solution:
- We proceeded to clean the fan blades and remove the built-up dust from inside the cooler.
- We also recommended moving furniture further away from the unit to prevent air from being blocked.
- Lastly, we flipped open the float valve to stop water from flowing in and tightened hose connections.
- We provided our client with an easy monthly maintenance routine.
Outcome:
- Airflow: Client was able to feel a strong flow of air throughout the room
- Cooling Power: Room was now able to receive cool air
- Leaks: Fixed by flipping open the float valve to stop water flow
Customers avoided needing a costly service call with minor DIY troubleshooting
Conclusion: Oftentimes, weak airflow can be caused by something as simple as blocked air vents or furniture located too close to the unit. Water leaks are usually caused by a broken float valve or loose connections.
Troubleshooting Tips
Why is my evaporative cooler not blowing cold air?
Dirty or dry cooling pads, a faulty water pump, or low water levels are the most common causes.
How frequently should I replace my pads?
On average, you should replace your pads every 1–2 years. If you have hard water like us here in Cape Town, you may have to replace them more often.
Why does my cooler smell musty?
Mold and mildew can grow inside your pads and water tank. Leaving you with a musty smell. Drain your water tank monthly and clean your cooler to prevent buildup.
Why is my evaporative cooler leaking water?
Check to see if your float valve is working properly. If the hose leading from the valve to your unit is cracked or any of the connections are loose. These could be causing water to leak as well.
Can I run my evaporative cooler on humid days?
Certainly, but it will be very ineffective. Evaporative coolers thrive best in dry climates because if there is too much humidity in the air, it limits evaporation.
My cooler has white scale build up. How do I clean it?
Use a vinegar solution on the internal parts of your cooler. You can also add a water treatment product to your water to prevent further scaling.
Why is my air blowing weak?
Dirty pads, blocked air vents, or debris on your fan blades can cause this issue. Make sure to clean and wipe these areas.
