Reasons a Central AC Blows Warm Air

Reasons a Central AC Blows Warm Air
November 12, 2015 nobleair

Though temperatures are beginning to cool in the Phoenix area, we’re not quite to the point that you can just turn off your central air conditioner unit. There’s still plenty of use for your split system, and, there’s little more frustrating and aggravating than realizing it’s not blowing cool air, but does blow warm air. The truth of the matter is, there are dozens of variables which cause an HVAC to blow warm air instead of cold air. In some instances, the air conditioning will blow warm air for a short time, then, it will begin to cool. Regardless of the scenario, it will only get worse over time. All those complex components are made to be durable, but, wear and tear does take its toll.

Reasons a Central AC Blows Warm Air

First of all, if the unit is blowing warm air, that tells you it’s still delivering, but of course, isn’t cooling. This means the blower motor probably isn’t the culprit because air, though warm, is still being circulated through the system. However, this unfortunately doesn’t guarantee the blower motor is in its best operating condition. It’s just that this is an unlikely part of what’s going wrong with your central air conditioning system.

Split-system central air conditioners, used with forced air furnaces, take hot air from the house and blow it through an evaporator coil located in the top of the furnace to cool the air. The cooled air circulates throughout the house via the heat ducts then returns to the furnace as warm air to be cooled again. Central air conditioners can work for years without problems if properly maintained and serviced annually. If they aren’t working properly, call a trained technician. —

This very situation is why you should have your system serviced on a regular basis. This allows an experienced technician not only to tune it to its peak operating, but also, to spot any potential, future problems with the unit and its various components. Though there are several reasons a central AC blows warm air, here are the most common problems to troubleshoot:

  • The thermostat is on the wrong setting. While this might seem overly simplistic, it sometimes happens. Check your thermostat to ensure that it is set to the cool position and not to the heat setting. In addition, look at the temperature setting, as well as the fan setting.
  • The breaker is tripped or blown. There are two power sources for these units. When the external breaker trips or blows, the outside unit loses power, which of course, means that it can’t cool the air circulating through your home. However, the inside likely still has power, which is why air is blowing but isn’t being cooled.
  • The evaporator coil is dirty because of a clogged air filter. If the air filter is dirty and/or blocked, it can’t function properly which negatively impacts the evaporator coil. You should change the filter and clean the evaporator coil.
  • The freon refrigerant level is low and/or leaking. When a unit blows warm air instead of cool air, it could be an indication the refrigerant is low, or, there’s a leak. In both instances, you need to call an experienced technician to diagnose and fix the problem.
  • The condenser unit is dirty. If there is something that’s blocking your outside unit, it’s probably choking the condenser unit, which needs free airflow to operate. Clear the immediate area around the outside unit.

Another two possibilities for warm air blowing from your central AC unit is there’s a misdirection in leaky ductwork, or, there is something wrong with the wiring. In either case, you’ll need to contact a licensed technician.