Why does it seem like an air conditioner stops cooling your home or business on the hottest summer days? You hear your AC turn on and adjust the thermostat repeatedly, but all you get is an uncomfortable warm airflow. We don’t know why air conditioners fail at the most inconvenient times, but if your air conditioner is running and not blowing cold air, it could be due to a range of common causes.
Common Causes: Why Your AC Is Not Blowing Cold Air
The operation of an air conditioner is pretty straightforward: an evaporator, condenser, compressor, and refrigerant work together to create cool air in your home or business. The condenser releases heat by converting refrigerant to a liquid, and then the evaporator absorbs heat by converting refrigerant back to a gas. The compressor is responsible for circulating and pressurizing the refrigerant so the other components can do their job.
If your AC is not cooling, common causes are a bad thermostat, an incorrect setting, a dirty air filter, or issues with the air conditioner’s components. Here are the usual suspects when your AC stops keeping you cool.
Leaking Refrigerant
Low refrigerant levels are typically caused by a leak that often goes unnoticed until the cold air stops. Signs of a refrigerant leak include poor airflow, an AC not blowing cold air, and ice on the evaporator coils. You can have the refrigerant refilled, but it’s a temporary solution at best. A refrigerant leak will continue and cause cooling problems until it is repaired.
Dirty Air Filter
When your air conditioner is running but not cooling, the problem could be something as simple as a dirty filter. Your AC filter catches dirt, dust, and other particles to prevent them from reaching the air handler. Keeping the interior components of an AC system clean is essential for proper cooling and avoiding unnecessary wear and tear. Plus, a clean air filter helps keep the indoor air clean and healthy.
Frozen Evaporator Coil
Signs you may have a frozen evaporator coil include higher-than-usual cooling costs, excessive condensation drainage, and an air conditioner not blowing cold air but running. While evaporator coils can be unfrozen, it’s critical to have a professional determine the cause to prevent it from happening again.
Clogged Condensation Drain Line
A clogged condensation line prevents an air conditioner from properly draining, which can cause mold growth and water damage, and prevents an AC from blowing cold air. If the condensation water backs up into the AC unit, it can cause significant damage to components and electrical circuits. Musty odors near vents, pooling water indoors, and a system shutdown are common signs of a clogged drain line.
Malfunctioning Thermostat
If you notice your air conditioner running but not cooling, check the thermostat settings. Ensure the controller is set to cool and programmed to the desired temperature. If the AC won’t turn on, turns on and off on its own, or produces inconsistent temperatures, you may want to invest in a new thermostat. A professional HVAC technician can check your thermostat and AC to determine the problem and suggest practical solutions, like a modern programmable thermostat.
Dirty Condenser Coils
The condenser fan pulls outdoor air into the AC unit through the condenser coil to pull heat out of your home or business. A dirty or obstructed condenser coil can lead to inefficient operation, unusual noises, or an air conditioner not blowing cold air but running. Coil cleaning is part of the recommended maintenance for most air conditioner units. An HVAC maintenance company can clean your coils each season, or you can carefully vacuum or brush away the dirt and debris.
Failing Fan Motor
A damaged or malfunctioning AC fan motor can cause buzzing or banging noises, work intermittently, or not power on at all. A fan motor that’s not working correctly can lead to an air conditioner that’s not cooling properly, weak airflow, and tripped breakers. If you notice signs of a failing fan motor, an HVAC expert can determine if the problem is the motor, the capacitor, or another related component.
Compressor Issues
The compressor is the engine of your AC system that makes the other components go. Without the compressor pressurizing the refrigerant, the evaporator and condenser can’t function properly. If your AC is not cooling, you hear unusual noises, or your breakers trip over and over, a bad compressor is likely to blame. Due to its complexity and location, compressor repairs and replacements should only be performed by a professional HVAC service.
Electrical Problems
An air conditioner not blowing cold air but still running, accompanied by frequently blown fuses, can mean there is an electrical issue. Faulty capacitors, overloaded circuits, and loose wiring are some of the most common causes of electrical problems in AC units. Wiring and connection issues can cause damage to the compressor, thermostat, and many other components of an air conditioner.
AC Not Cooling? The Role of Maintenance
An air conditioner not cooling could be the result of failing components, faulty wiring, and other factors that could have been prevented with proper maintenance. Routine maintenance plays a critical role in ensuring your air conditioner cools consistently and efficiently. An annual professional maintenance service that includes AC tune-ups, coil cleaning, and other tasks can help prevent costly repairs and a failed cooling system.
When to Call the Pros
If your AC is not blowing cold air and you’ve checked the components listed above, it’s time to call in the HVAC pros. When your AC is not cooling properly, you don’t have to suffer—our experienced service technicians have the skill and experience to get the cold air flowing again. When you want proven, reliable air conditioning maintenance and repair services, you can trust the experts at Bill Howe HVAC. Give your AC the care it deserves and beat the heat when you contact Bill Howe for heating and air conditioning services in San Diego County.
