Most Common Air Conditioning Problems

When the summer heat and humidity ramp up, you need a properly functioning air conditioning system to keep you cool and comfortable. So when something goes wrong – like weak airflow or strange noises – it’s only natural to worry about whether the system is on the brink of a full breakdown.

Recognizing the early signs that your AC needs attention can help you catch problems before they become major (and expensive) repairs. Below are some of the most common home AC issues that HVAC technicians see daily and what might be causing them.

Common Home AC Repairs

If your air conditioner is struggling to turn on, produce cool air, or maintain a consistent temperature, it may be experiencing one of the following AC problems.

Refrigerant Leak

Refrigerant is the lifeblood of your air conditioner – it absorbs heat from your home and releases it outside. If your system has a low refrigerant charge or a leak, it will struggle to keep up, and its cooling performance will drop. A certified technician can recharge the system to proper levels and repair the source of the leak to restore efficiency and performance.

Drainage Issues

Aside from cooling your home, your AC also removes moisture from the air to balance humidity levels. That moisture collects in a drip pan and drains outside through condensate lines. If those lines become clogged with dirt and debris, water can back up into your system. This can raise humidity levels, reduce cooling performance, and even damage internal components.

An AC repair technician will clear the drainage lines and inspect the drip pan for any potential damage. If any components have been damaged by water, the technician will recommend appropriate repairs.

Broken Compressor Fan

Your air conditioner’s outdoor unit houses the compressor, fan, and condenser coils. These parts work together to release heat from your home. If the outdoor fan stops working, that heat transfer is interrupted. The system may overheat, shut down, or damage the compressor – one of the most expensive components to replace.

Electrical Component Failures

If your AC won’t turn on, electrical problems may be to blame. Blown fuses, tripped breakers, or faulty capacitors can all disrupt the system. While homeowners can try resetting a breaker or replacing a fuse, ongoing issues could point to deeper electrical problems and require the know-how of a professional.

The contactor – a switch that sends power to the compressor and fan – may also fail over time. An HVAC technician can test and replace faulty electrical parts as needed.

Frozen Evaporator Coil

A frozen evaporator coil is often caused by restricted airflow, such as from a dirty air filter, blocked vents, or a failing blower motor. It can also happen if the system is low on refrigerant, which causes pressure and temperature drops that freeze condensation on the coil.

To fix it, ensure filters are clean, vents are clear, and airflow is unobstructed. A professional should inspect refrigerant levels and recharge the system if necessary.

Thermostat Problems

If your thermostat isn’t working properly, your AC may not turn on, shut off, or fail to reach the set temperature. This leads to discomfort and energy waste. Try checking the thermostat settings and replacing the batteries. If issues persist, a technician can inspect, recalibrate, or replace the unit.

Dirty or Clogged Condenser Coil

The condenser coil, located in the outdoor unit, releases heat that’s absorbed from inside. When it's covered in dirt and debris, heat transfer is blocked, causing your system to work harder and less efficiently. This can drive up energy bills, lengthen cooling cycles, and reduce the system's lifespan.

Routine coil cleaning by an HVAC technician can restore efficiency and help your system run at peak performance.

Compressor Issues

The compressor pressurizes refrigerant and circulates it through the system. If it fails, your AC can’t cool your home. Compressor problems often stem from electrical failures, refrigerant imbalances, or simple wear and tear over time.

Because compressors are complex and costly to replace, it might be worth replacing the entire system depending on its age and condition.

Blower Motor Issues

The blower motor is what moves cool air through your ducts and into your home. If the motor fails or underperforms, airflow will be weak or nonexistent which can lead to uneven cooling, reduced comfort, and higher energy bills.

Blower motor problems often stem from worn bearings, overheating, electrical faults, or debris in the housing. Regular inspections can catch issues early and prevent complete failure.

Regular Maintenance Can Help Prevent AC Problems

While no AC system lasts forever, regular maintenance can drastically reduce the number and severity of repairs. Preventive care ensures your system is running efficiently, helps catch small issues before they become big problems, and extends the life of your unit.

At minimum, schedule a professional HVAC tune-up once a year, ideally in the spring before cooling season begins. A technician will clean the condenser coils, check refrigerant levels, inspect electrical components, test the thermostat, and lubricate moving parts. This routine visit can prevent many of the issues listed above and give you peace of mind all summer long.

In addition to professional maintenance, homeowners can also do their part. Change the air filter every 1-3 months, keep the area around the outdoor unit free from debris, and inspect visible components for signs of wear or damage. Together, these habits help keep your AC system in top shape and reduce the chance of unexpected breakdowns during the hottest days of the year.