Every summer, thousands of homeowners in the southwest Chicago suburbs get blindsided by an AC breakdown in the middle of a heat wave. The frustrating part? Most of those breakdowns were predictable. The warning signs were there — they just weren't recognized.
Here are 7 signs your AC system is telling you it won't make it through another summer — and what to do about each one.
1. It Takes Much Longer Than Usual to Cool Your Home
If your AC runs for hours but your home never reaches the set temperature, something is wrong. The most common causes are low refrigerant, a dirty evaporator coil, a failing compressor, or a system that's simply too small for your home. Any of these require professional diagnosis. Don't ignore this — a system working twice as hard uses twice the electricity and wears out twice as fast.
2. You Hear Unusual Noises
A healthy AC system runs quietly. If you're hearing grinding, squealing, rattling, banging, or clicking sounds, something mechanical is failing. Grinding usually means the motor bearings are worn. Squealing often indicates a belt or motor issue. Banging or rattling can mean a loose component that could cause serious damage if left alone. Turn the system off and call for service.
3. Your Energy Bills Spiked Last Summer
If your electric bill was noticeably higher last summer without a change in usage habits, your AC is losing efficiency. This is one of the earliest signs of a system in decline. A system that used to achieve a certain cooling output now requires more energy to do the same job — meaning it's working harder and wearing out faster.
4. The System Short-Cycles (Turns On and Off Repeatedly)
Short-cycling — when the AC turns on, runs for a few minutes, shuts off, and immediately starts again — is a serious problem. It can indicate an oversized system, a refrigerant leak, a failing compressor, or electrical issues. Short-cycling prevents the system from completing a full cooling cycle, leaves your home humid and uncomfortable, and dramatically shortens the life of the compressor.
5. There's Ice on the Unit or Refrigerant Lines
Ice forming on your AC — either on the outdoor unit or on the copper lines running to it — is a sign of restricted airflow or low refrigerant. Both cause the evaporator coil to drop below freezing and ice over. When ice forms, the system can't cool effectively. Turn the system off and let it thaw, then check your air filter. If the filter is clean and ice keeps forming, you have a refrigerant or airflow problem that needs professional attention.
6. The System Is 12–15+ Years Old
The average central AC system lasts 12–17 years with proper maintenance. If your system is in this age range and showing any other symptoms on this list, replacement is likely the smarter financial decision. A new high-efficiency system (16+ SEER) can reduce cooling costs by 20–40% compared to an older system. Financing is available — you don't have to pay for it all upfront.
7. Warm or Uneven Air Coming From Vents
If some rooms are cool and others are warm, or if the air coming from vents isn't cold, you have a problem. This can indicate low refrigerant, a failing compressor, ductwork leaks, or a system that's simply not sized correctly for your home. Any of these require professional diagnosis.
What To Do If You See These Signs
Don't wait until July. Spring is the best time to address AC problems — technicians are available, parts are in stock, and you have time to make a thoughtful decision about repair vs. replacement instead of a panicked emergency call during a heat wave.
Todd's HVAC Services offers $49 AC tune-ups for Homer Glen, Orland Park, Tinley Park, Mokena, and surrounding areas. During a tune-up, we'll identify any of these warning signs and give you an honest assessment of your system's condition. Call or text 708-742-7935 to schedule yours before summer hits.
Related: Why Homer Glen Homeowners Should Get an AC Tune-Up This Spring