There’s never a good time to find out your AC system isn’t working correctly. However, when they stop working, it tends to be in the summer when you use them and rely on them the most.

To avoid facing expensive repairs or replacements at the worst possible time, like a roasting-hot Southern California summer day, it helps to look for warning signs. Although many things can go wrong in an AC unit, the compressor is one of the biggest things to watch.

What Is an AC Compressor?

You’ve probably heard the term, but you may not know what an AC compressor does. Think of it as the engine that powers the system. When refrigerant comes from the indoor evaporator coils, it must move to the condenser coils.

Before that transfer can occur, the refrigerant must be compressed, which is the compressor’s job. The condenser coils heat and pressurizes the refrigerant, transforming its state from liquid to gas.

When the compressor is overloaded, performance can decline, and the entire system can fail. That’s why it’s good to know how to tell if an AC compressor might be overloaded.

Residential air conditioning unit outdoors with fan and coils

Signs That an AC Compressor Is Overloaded

Each of the following is a sign that the compressor is overloaded. The existence of one of them does not necessarily mean the compressor is the problem, but nevertheless, the system is trying to tell you something.

  • A jump in energy bills. The compressor uses more energy than any other part of an AC system does, so if you see a sudden noticeable increase in your power bills during AC season, there’s a decent chance the compressor is performing inefficiently and therefore consuming more energy.
  • Unusual sounds. Typically, about the only sound you hear from an AC system is a smooth, relaxing one as it courses cool air throughout the house. Be on the alert for unusual noises such as clanking, ticking, buzzing, rattling, or rumbling. These might be signs that the compressor is working too hard or that the electrical component may be failing.
  • Blown fuses and tripped circuit breakers. If you are experiencing blown fuses or tripped circuit breakers shortly after the unit turns on, something is likely wrong with the compressor. An overworked compressor can create power surges that cause these problems.
  • Vibrating or shaking at turn-on. This is called a hard start because the unit is having a hard time starting up, and it’s usually a sign that the unit is close to failing.
  • Leaking refrigerant. The refrigerant is what makes the warm air cold, and if you’re noticing water puddles or other signs of moisture near the unit, there might be a leak, or the compressor may not be working correctly. It also means the air may not be as cold as you want it to be.
  • Reduced airflow. When a compressor gets weak, there will be reduced airflow, and the flow should be consistent when things are working correctly.
  • The air is not cold enough. If the air coming out is more warm than cold or just not as cold as you expect it to be, you might just need more refrigerant. However, this can also indicate a leak in the compressor.

American AC Service and Repairs

When you see signs of AC compressor trouble or other problems with your HVAC system, don’t procrastinate. Sometimes the fix is easy and inexpensive when caught early, and waiting can lead to system failure and/or extensive, expensive repairs.

American is a name you can count on for AC services in the Los Angeles area, including air conditioning repair in Simi Valley and emergency AC repair in Woodland Hills and elsewhere. Our experienced technicians have the training and the tools to diagnose the problem and get the job done right.

Need to schedule a service? Contact us!


James Smith

As you can tell from our humble beginnings in 1981, we began as a family-owned business and stayed a locally owned air conditioning and heating company in Los Angeles county for nearly 40 years.