Few things are more stressful than waking up on a frigid Chicago morning only to find that your furnace has stopped working—or losing air conditioning during a humid July afternoon. The good news is that your HVAC system usually shows warning signs before it completely fails. By recognizing these issues early, you can avoid costly repairs and uncomfortable downtime.

The first sign to look for is weak or inconsistent airflow. If some rooms in your home feel perfectly comfortable while others remain too hot or too cold, there could be a problem with your blower motor, ductwork, or even something as simple as a clogged filter.

Strange noises are another red flag. Loud banging, screeching, or clanking sounds typically mean something inside the system is loose or failing. Unusual sounds are never normal and should be checked out right away.

If you’ve noticed your energy bills creeping up without any major changes in your household’s usage, your HVAC system may be losing efficiency. An aging or malfunctioning unit will work harder to heat and cool your home, driving up costs. Uneven heating or cooling throughout your house is another common sign. Hot and cold spots often indicate thermostat issues, duct leaks, or a system that’s struggling to keep up.

Pay attention to unusual odors as well. A musty smell might mean mold inside your ductwork, while a burning odor could signal serious electrical issues. Either way, both require immediate attention.

Another issue to watch for is frequent cycling. If your furnace or air conditioner is constantly turning on and off, it could be short-cycling—a problem that leads to wasted energy and unnecessary wear and tear. And finally, age matters. If your system is more than 10–15 years old, repairs will become more frequent, and replacement may be the smarter financial choice.

Don’t wait until your HVAC system completely shuts down. If you’ve noticed any of these signs, call Planz Heating & Air today for fast and reliable repairs. We offer same-day service in Chicago to keep your home safe and comfortable when it matters most.