Why is my HVAC Unit Not Cooling?

The last thing you want during a South Carolina summer day is an air conditioner that won’t work. While there are numerous reasons that your air conditioning isn’t blowing out cool air, some of the most common issues are explained below.

Thermostat settings are set incorrectly – The thermostat is used to sense the surrounding air temperature and relay the information to the compressor, in which case it will start or stop. If you know that your thermostat works, double check the settings to make sure that it is calling for cooling. If it is not set on cooling, the thermostat won’t call for the compressor to start and the unit will not turn on. If all of these check out, it is likely to be one of the next issues.

Poor air flow – Proper air flow is essential to satisfactory cooling; if filters or coils are dirty, air flow will be reduced, less heat will be removed from the building, the system won’t operate as efficiently and the system will struggle trying to cool. Additionally, this can force the compressor to work harder, which can lead to abnormally high head pressure and even costly compressor burn-outs. It is extremely important that filter changes and coil cleanings are not overlooked! More information on filter changes and coil cleanings can be found in our FAQs Section.

Refrigerant leaks – During the cooling cycle, refrigerant in the system is used to absorb heat in the evaporator coil and dissipate it at the condenser coil. However, if your system is low on refrigerant, the unit will not be able to remove adequate amounts of heat and the system won’t be able to cool effectively, especially if the evaporator coil freezes. While refrigerant can be added to the system as a short-term fix, ultimately the leak will need to be located and sealed to prevent further issues.

Wrong sized system – Skimping on your HVAC system can lead to predictable outcomes. If a buyer purchases a unit that doesn’t have the cooling capacity to cool the specified area, then it isn’t surprising that the room won’t be able to cool the room to the desired temperature on very hot days. A unit should be purchased based on the heating and cooling loads of the area in which it operates, rather than buyer’s budget.

Compressor issues – Typically, problems with the compressor are due to smaller problems that were never properly addressed. Because the compressor is the “heart” of the air conditioning, there is virtually no chance that your system will run correctly if your compressor won’t run correctly. Changing a compressor is a costly and time consuming fix, so if you have an old HVAC system, you may benefit changing out the whole system instead.

While some of these issues – such as filter changes – can be fixed by yourself, more complex issues should be handled by licensed contractors. Incorrectly diagnosed issues can compound the problems and lead to more damage and expenses. If you think your system isn’t working appropriately, call the pros today!