Man fixing an evaporative cooler

How to Fix an Evaporative Cooler Not Blowing Cold Air

September 7, 2020 7:41 pm Published by Leave your thoughts

When you’re in the middle of a heat wave and your swamp cooler goes on the fritz, it can leave you frustrated and uncomfortable. However, there are only a few basic reasons why this would happen, so it should be fairly easy to quickly troubleshoot the issue and find out what’s wrong. In most cases, there will be a simple solution which you can manage yourself, to get the unit back in service and once again blowing cold air.

How Swamp Coolers Work

A swamp cooler operates on the same basic principle as the way sweat works in cooling down your skin. As water gets evaporated into the air, it takes with it a certain amount of heat from the air, and replaces it with a droplet of water. This is accomplished by soaking cooling pads in water and then waiting for those pads to start the process of evaporation. This drying process actually cools down all the surrounding air close to the swamp unit, and then a small fan works to spread that cool air all around the area.

This is much different than the way an ordinary air conditioner operates, because that appliance draws a great deal of electricity in order to keep refrigerant running through condenser coils which are responsible for creating cool air. Swamp coolers require far less electricity, and work through the power of evaporation, and most of the electricity used by a swamp unit actually serves to run the fan, so cool air can be circulated.

6 Most Common Reasons for Why an Evaporative Cooler Stops Blowing Cold

If your swamp cooler is not blowing cold air, there are several possible causes which you’ll have to check out. In most cases it will not be a mechanical failure, but the cause will be some type of external issue. Probably the single most common reason your swamp cooler is not blowing cold air is that the circuit breaker has tripped or the fuse has blown. These are installed so as to avoid electrical damage to the unit, so it doesn’t get fried in the case of an electrical overload. 

Another common cause of cooling unit failure is faulty wiring, and this may be evident if you have persistent power surges that trip the circuit breaker. To verify this, you’ll have to check the wires leading to the circuit breaker and the fuse, scanning for any black spots which appear nearby. It’s also possible that the thermostat could have a problem, and if this is the case, it will simply have to be replaced, because it’s not a unit that you can troubleshoot. 

Any problems you’re having with your swamp cooler might also be attributed to low-voltage, and your unit will not operate correctly when it doesn’t have a sufficient electrical supply. The best way to avoid problems like this is to install a voltage stabilizer on your unit, so that the swamp cooler doesn’t get damaged by repeated occurrences of low-voltage.

Another possibility when your cooling unit isn’t blowing cold air is that you have a problem with either the fan motor or the belt. These are internal components, and it will sometimes happen that the belt which connects the motor and the fan will slip off, or will become broken. If the belt is still serviceable, you can simply put it back on, and if not you will have to replace it entirely. It’s also possible that the fan motor could fail, but such incidents are fairly rare, because these are very durable units and generally have long service lives.


How to Assess the Cause of Your Swamp Cooler Failure

How to Assess the Cause of Your Swamp Cooler Failure

If your swamp cooler will not turn on, the first thing you should check is your circuit breaker and your fuse box, and if that isn’t the problem, you should check to see if the thermostat was set too high. If you should notice a musty odor coming from your cooling unit, you should check your evaporating pads and replace them if needed. 

There could be stagnant water in the sump, and if this is the case it needs to be drained and cleaned. When you add in new water, it’s a good idea to put a teaspoon of vinegar in, to ensure that the water stays clean longer. If you notice your unit dripping, the problem could be an improperly adjusted float valve.

This can be manually adjusted so that you are sure the unit gets sufficient water without overflowing. If your cooling unit is not blowing sufficient cold air, the first thing to check would be your water system. Make sure there’s enough water in your unit, then check the water pump to be sure it’s operating correctly, and verify that the distributor is not clogged.

How to Get Your Swamp Cooler Blowing Cold Again

In order to be sure that your cooling unit continues to blow cold air, there are a few basic steps you can take to keep it operational. First of all, you should verify that the average humidity in your region is not too high, because swamp coolers are much less efficient in areas of high humidity. Checking your water supply is always a good idea, and you can do this by ensuring that the pump and the hose are properly connected and that the water distributor is also firmly connected.

Since the swamp cooler operates better with natural airflow, it’s a good idea to have some windows in your home open, so there is sufficient airflow to keep your cooling unit blowing cold air. Probably the most common problem with any cooling unit will be that the pads build up excessive scale which interferes with their operation. A good way to prevent this is to drain the water out of your cooler each week, and you may even want to use a purge pump to prevent debris and scale from clogging up your evaporative pads.

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This post was written by Mike Nicolini

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