Summer temperatures in East Tennessee often linger well into October, with sudden swings of 20 degrees or more from day to day. The climatic yo-yo is not only hard on humans adjusting to the shorter days and colder nights. All that transitioning from air conditioning to heating in the span of a few hours day after day can wreak havoc on your HVAC unit if there are any underlying maintenance issues. We always recommend a maintenance check-up during seasonal transitions, and if you haven’t scheduled one yet, you might already be in trouble. Below, we outline 9 common fall HVAC problems that are a clear sign your system needs a tune up before winter.

1)    Dirty Air Filters

Spring is traditionally the harbinger of allergies, but we East Tennesseans know that fall can be just as bad. For your HVAC unit, the issue is much worse in the fall, especially if you haven’t changed the filters all summer. Pollen and other types of air pollution build up in the air filter over time, making it difficult for the unit to bring in air at all—let alone clear air. Changing the air filters regularly not only makes sure that your system functions as efficiently as possible, but it also ensures better home air quality.

2)    Rattling & Other Noises

If you live in an older home or have an aging HVAC unit, some noise might just be part of the regular transition into cooler temperatures. But what if you’re hearing something new? Unusual whining or squealing could indicate a motor issue. Major rattling usually means something substantial—like a rock or stick—is stuck in your outside unit. Other noises can indicate airflow issues or dirty burners, and any of these noises left unchecked could lead to furnace failure. It’s not just your imagination. Persistent new noises definitely merit a service call.

3)    Clogged Systems

Leaves are arguably the most beautiful part of autumn, but they’re also one of the most damaging to your HVAC systems and general house maintenance. Your HVAC needs clear drainage through sewer lines for the furnace to function properly, and debris such as leaves often gets sucked into vents, causing clogs. If your system is struggling to operate—almost seeming like it’s wheezing to life—then leaves and/or dirt clogging the system is often the culprit this time of year. You can easily hose down the outside coils—after shutting all the power off to the unit first, of course—if there is visible debris, but otherwise call a professional.

4)    Leaky Refrigerant Pipes

Coming off a long, hot summer means the refrigerant pipes in your HVAC unit finally get to wind down a bit. Just like when you’ve had a stressful season at work, when the pressure alleviates, things can begin to fall apart. Refrigerant pipes may end up leaking, and these leaks are dangerous. Don’t attempt to fix them yourself. They require a trained maintenance professional to fix.

5)    Continuous Blowing

You’ve checked your fan switch three times to make sure it isn’t on by mistake, but the HVAC is still blowing. If you didn’t put the fan on by accident, there could be an issue in the fan relay that turns the blower on when your house needs heat. If this relay sticks, then the blower won’t turn off. Your system might also be keeping the blower on as a safety precaution to cool down your furnace if it’s overheating. Check that fan switch one last time, and if it’s still blowing, it’s time to get an HVAC checkup.

6)    Broken Thermostat

You know what it’s supposed to feel like in your home. If suddenly your HVAC unit doesn’t seem to have the same sensitivity to hot and cold that you do, the thermostat could be broken. Even slight misreads in the thermostat can affect the temperature in noticeable ways, and dirt build up, dead batteries, misaligned settings, and faulty wiring can all cause thermostat malfunction. You can check your thermostat health by noting the temperature outside and inside the house and seeing how much you need to adjust the thermostat for heating or cooling to activate.

7)    Faulty Pilot or Ignition Sensor

If your heater is failing to turn on when the temperature drops overnight, it could easily be due to a sensor or faulty pilot or ignition. Temperature changes put a lot of strain on the sensors in your system, and sensor failure is one of the more common HVAC system issues. Likewise, a dirty pilot or burners or simple wear and tear over the summer can cause a pilot outage or delayed ignition. It’s not a complicated problem to fix, and a routine maintenance check can solve it quickly.

8)    Blown Fuses

Much like the HVAC unit sensors, fuses and breakers often struggle with the temperature swings common in the fall. Also, a clogged air filter or dirt in your outside unit can cause your blower to overheat, which trips the breakers. Blown fuses are often a sign that your air filter is too dirty for the unit to function properly. If you replaced your filter recently, the problem might be with the furnace or the circuit breaker itself. Either way, it’s best to call a professional to deal with any work that involves high voltage.

9)    Dirty Evaporator Coil

We’ve all felt it before: it’s late October in East Tennessee and still 80 degrees, and we swear that the HVAC has just given up after months of cooling. It might not be your imagination. Dirt and debris that collect over the fall can build up on the evaporator coils of your system and make it significantly more difficult for your HVAC unit to function. Outdoor coils clog easily, and indoor evaporator coils can also become dirty if you haven’t changed your furnace filter in a while. It’s hard to know if coils are the issue without a close examination, so an HVAC maintenance call is in order for this issue too.

Will Your HVAC Last the Winter?

Your HVAC unit is a complicated system that relies on multiple integrated parts. If any one of these mechanical components isn’t functioning properly, you could be paying a lot more in energy bills, maintenance bills, or even for a new unit before you need one. The last thing you want is to realize during the first major chill this winter is that your furnace is struggling or simply won’t turn on. Take advantage of fall’s cooler nights and cold snaps to ensure everything is functioning properly, or better yet, keep a regular maintenance schedule with a licensed service contractor for your HVAC unit.

East Tennessee HVAC Installation and Maintenance

City Heating and Air Conditioning is here to keep your HVAC units running efficiently throughout the seasons despite the swings in temperatures and leaf build up in fall. Our experienced HVAC technicians know how to check for common debris and overheating issues and can ensure your unit is ready for winter with a simple checkup. We will do everything necessary to make sure your HVAC system runs as efficiently as possible so that you can stay comfortable while keeping your energy bill in a comfortable range. To schedule a HVAC installation or maintenance appointment with a trusted Knoxville HVAC company, give City Heating and Air Conditioning a call at 865-938-1005 or fill out our online form.