Why is your AC System Blowing Hot Air?
Why doesn’t your AC unit seem to be working? Why is there hot air when cool air should be blowing freely? Sometimes the answer is deceivingly simple. Believe it or not, homeowners frequently forget to switch their thermostat from heat to cool as the seasons change. Home AC units also have dozens of parts that must function properly in order to efficiently cool your home. When one part goes out, the whole unit could malfunction. One common problem many residents notice is that their air conditioner blows warm air. This warm air is likely the result of a bad part or a refrigerant leak and will require one of our technicians from Tex-Perts Cooling & Heating to look at it. Here is the full list of problems which may answer the question of why is your AC system is blowing hot air?
Sitting at the top of the list is one common cause for AC units to malfunction. Refrigerants can leak for a variety of reasons, but you’re likely not outside to see the leak. If it leaked on Friday, then on Saturday when you are sitting around the house you won’t be able to see the leak outside because it will be empty.
Unfortunately, there is never one exact reason for a refrigerant leak, but it could be that a joint came loose due to heavy use. New AC units may have been assembled poorly by the manufacturer, but this is a rare sight when buying any respected brand (we prefer Lennox and York). Lastly, a worn service valve could cause the leak. The leaks are generally random and unpredictable, but heavy use and turning the AC on high after being off all winter can cause damage to the outside unit, causing a variety of wear-and-tear damages. To prevent the unit from leaking in the future, keep your eye on it and have the unit serviced before turning it on for the summer or soon after turning it on.
Frozen AC Unit
To many homeowners’ surprise, air conditioners can actually freeze. Yes, freeze solid inside into a block of ice. In fact, this is the most common cause of air conditioners to blow warm or hot air. The first thought when homeowners see the ice is “Why would it blow warm air if it’s frozen?” The frozen part is the evaporator coil, which can block the cool air flowing into your home. Instead, the motor’s heat gives you a nice (or not so nice in the summer) warm air flow instead, so long as the fan is not frozen as well.
Inside of the unit, condensation can occur on the coils and is intended to evaporate. This condensation can build up and freeze if the temperatures at which the AC is trying to blow falls below 32ºF. Typically this happens on a hot day when homeowners turn their AC on the highest setting. To prevent this from happening, you should keep your thermostat on auto around 70 or 72ºF and keep an eye on the unit, inside and out. Have a service technician take a look at it at the beginning of the summer season as well.
Put simply, some homeowners forget that they have to turn the thermostat to “cool” from “warm” in the winter. If you or your kids accidentally set it to warm, the unit will start blowing warm air to maintain the temperature instead of cool air. Also, make sure the unit’s temperature is not set too high on auto.
Generally, homes with kids means things get messed up, and your thermostat is no exception. Others merely forget to switch the setting over. We recommend making a note to yourself before summer comes to turn it on “cool” mode and stick it to the fridge or in your calendar for the first day of summer.
When is the last time you changed or cleaned the air filter in your AC? Most people never do until something goes wrong. Air filters do get dirty and this blockage won’t clear up until you or a technician takes it out and replaces it. The filter alone will not cause warm air to blow, but it will contribute to the problem and reduce cooling effectiveness significantly.
Air filters are there to catch dirt and debris that may be flowing through your internal unit. If they are doing their job, they become dirty and need to be cleaned or replaced. You should check on it regularly.
Miscellaneous electrical problems could be the source as well. There are a ton of wires flowing in out and around the external unit and internal unit. If one of these wires is frayed, cut, or otherwise damaged, it could cause poor performance or even break the unit down entirely.
Wiring can be frayed if it gets burnt by overheating, but this is an extremely rare occurrence. Generally, wires are cut by the family pets, such as cats and dogs. If the wire is exposed and they decide to chew on it, the unit will malfunction. To prevent this from happening, you should make sure wires are not sticking out. If they are and cannot be fixed, we recommend keeping both your external and internal units protected from animals with some sort of wall or fence around it.
For more information about AC repairs related to the question, “why is my AC system blowing hot air,” contact Tex-Perts Cooling & Heating.