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Portable Air Conditioner Troubleshooting and Common Complaints


Properly working heating and cooling systems are integral aspects of a comfortable home or workplace, and during the summer months, a malfunctioning air conditioning system will leave you sweltering in the heat. Unfortunately, many problems associated with more complicated cooling systems can stem from flawed installation, poor service, or insufficient maintenance, but if you encounter a problem with your portable AC, rest assured that because it's a self-contained unit, it's easy to operate, maintain, and yes, even troubleshoot.

In the event that your portable air conditioner fails to work properly, getting your unit to work is usually a matter of making a few simple repairs. To troubleshoot your portable air conditioner, see if any of these situations apply to you and follow these simple tips:  

My AC Isn't Providing Enough Cooling

Keep in mind that portable air conditioners are ideal for supplemental cooling or used to cool a small area such as a bedroom or living room. Because they exhaust room air as they cool, they will usually not be as efficient as a window unit of comparable cooling capacity. With that said, two primary factors can contribute to inadequate cooling: an incorrectly-sized portable AC and extreme ambient temperatures.

Portable ACs are primarily sized by BTU ratings, and if your portable AC has the wrong BTU rating for your particular area, cooling efficiency will be affected. Too high of a BTU rating will cause the unit to cycle off too quickly, while a low BTU rating will not adequately cool.

On the other hand, the ambient temperature can also be a contributing factor to insufficient cooling. The exhausting of room air and the resultant need for replacement air from un-cooled areas (such as the outdoors) will make it difficult for the portable AC to make headway as it struggles to lower the temperature of the room. Furthermore, other factors such as excessive sunlight or low ambient temperatures can also hinder cooling.
icon_bulb-blue-1 Portable Air Conditioner Buying Tip:
To learn how to properly size a portable AC, see our sizing page, or learn how to maximize your portable AC's efficiency here.

My Portable AC Won't Start

There are a few causes that could prevent a portable AC from operating, and these primarily stem from power problems. Start by making sure the power cord is plugged in correctly and check to see that the cord itself isn't damaged. Also check the wall plug and circuit breaker. Try resetting the circuit at the breaker box, or even change the socket or outlet. If any of these steps fail to resolve the problem, take the portable air conditioner to a qualified electrician and have the fuse replaced. 

My Portable Air Conditioner Stops Operating On Its Own

Check to make sure the timer is not on because an active timer could be causing the unit to cease operation. Also, if  the ambient temperature in your room is lower than the set temperature, this could be causing your portable air conditioner to shut off. To remedy this, wait for the room temperature to rise until operating the unit.

My Portable AC Won't Cool

A portable air conditioner may not cool for several reasons. Check the filter by removing the unit's grill and clean the filter. Also check for clogs in the evaporator or condenser coils by light vacuuming. Make sure the evaporator isn't frosted over, but if it is, allow it to defrost and normal operation should resume. Lastly, as mentioned above, ensure the ambient temperature is lower than your AC's set temperature, as this can prevent cooling. However, if all of these steps fail to resolve your problem, the fan motor may be blown or the compressor may be malfunctioning, and in these cases, seek the help of a professional.

No Cool Air Comes Out of the Unit

This can result from excess frost on the evaporator or on the coils. Allow the evaporator to defrost and normal operation will most likely resume. However, if there is ice buildup on the coils, this can often be prevented by cleaning the air filters.

My Portable Air Conditioner Has Insufficient Airflow

If water appears in the tank but your unit isn't cooling, as mentioned above, the cooling coil could be frozen. Most airflow problems are due to dirty filters, but the frozen coil could be a result of a low refrigerant charge. If this happens to be the case, a professional will need to correct the refrigerant charge.

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