Modern central air conditioners are complex systems with several potential points of failure. Most AC problems fall within one of a few basic categories. Here's an introduction to three common classes of AC problems.

1. Airflow Issues

Your HVAC system's main function is circulating air, and it needs an adequate supply of air to do this effectively. An airflow bottleneck at any point can bring down your entire system's energy efficiency. Fortunately, obstructed airflow is one of the easiest categories of AC problems for homeowners to correct.

The furnace filter is responsible for removing dust and other contaminants from the air your AC intakes. Clean or replace the filter each month so it doesn't get clogged with dust and create a blockage. Make sure your vents aren't covered by furniture and trim away weeds and shrubs near your outdoor condenser. With these steps, your AC will have the airflow it needs to cool efficiently.

2. Electrical Faults

Electrical problems refer to damage in the wiring, control boards, or other electrical components inside your air conditioner. Frayed or corroded wiring may create electrical shorts that cause your AC to overload and trip the circuit breaker frequently. In other cases, your AC may start and stop erratically or fail to start at all.

The start capacitor is one electrical component in particular that can prevent your AC from running if it fails. When you turn on the AC at the thermostat, the start capacitor sends a jolt of power to the condenser motor. If the capacitor burns out, it will need to be replaced before your AC will cool again. Call an HVAC contractor if your AC is showing signs of electrical problems or is producing a smoky odor.

3. Low Refrigerant

Your air conditioner circulates fluid refrigerant to remove heat from your home's air and dispel it outside. Low refrigerant levels have certain characteristic symptoms that are easy to identify. Refrigerant can be used indefinitely, so low refrigerant is always a sign of a leak.

The first sign most homeowners notice when they're faced with a refrigerant leak is that their AC is blowing air, but the air isn't cold. If this problem isn't addressed, you may start to see ice form on your AC refrigerant lines and evaporator coils. In some cases, you may even notice a sweet chemical odor or hear a hissing sound near your AC as refrigerant escapes.

Now you know the common issues that can occur in your central air conditioner's most important systems. Remember to call an air conditioning repair technician any time you're faced with an AC problem you can't solve.