Most Avoidable HVAC Malfunctions: Furnace and AC Unit Repairs

Emergency HVAC service calls are expensive and inconvenient for everyone involved. No one wants to be stuck with a broken AC during a July heatwave, frantically making a dozen phone calls hoping to secure a next-day appointment.

Situations like this can be avoidable with regular maintenance and annual professional care. Follow along to learn about the most avoidable HVAC system malfunctions and how to prevent future furnace and AC unit repairs. Doing so can save you thousands of dollars in the long run.

Most Common Furnace And AC Unit Repairs

According to the U.S. Department of Energy, certain furnace and AC repairs are needed more frequently than others. We broke down each of these common HVAC malfunctions to help you better understand how to avoid needing future repairs.

Most Common Furnace And AC Unit Repairs – ductwork in a wooden building

  1. Refrigerant Leaks

    A frequent cause for AC unit repairs is low refrigerant levels. Low refrigerant levels are usually caused by human error during installation or a refrigerant leak in the system.

    Underfilling refrigerant during installation can be accidental or a cost-cutting tactic. This is why it’s important to find a reputable HVAC service company with licenses and certifications. In this case, adding refrigerant to the system may solve the problem. Homeowners must ensure that their AC systems have the correct amount of refrigerant to maintain maximum performance and efficiency, so it’s best to leave this to professional technicians.

    Refrigerant leaks are a more serious AC unit repair. Professionals, like our technicians at Filterbuy LOCAL, should inspect the unit, find the source of the leak, repair it, and then test the repair to make sure it’s working properly.

  2. Inadequate Maintenance

    HVAC companies see inadequate maintenance from homeowners all too frequently. HVAC system neglect will have you paying for expensive AC and furnace repairs that are totally avoidable. Air filters and evaporator coils are two things homeowners need to remember to take care of. Failure to maintain your HVAC equipment shortens its lifespan and increases your energy bills by making your system less efficient. Paying minor maintenance costs upfront will save you thousands of dollars in the long run.

    Air Filter Maintenance

    Regularly changing your air filters is one of the best things you can do for your HVAC system. Air filters keep your indoor air clean by catching dust, dirt, allergens, and other pollutants as air circulates through your home. Over time, filters inevitably get clogged, which restricts airflow. This can make your HVAC system work harder than needed, potentially leading to higher energy bills, furnace/AC unit repairs, and even system failure.

    Changing your air filters at least once every 3 months can help prevent the need for AC and furnace repairs. By keeping up with regular air filter changes, you also ensure that your system stays efficient and your equipment last longer. Plus, it's an easy way to keep your indoor air quality high without doing much work.

    How Air Filters Help Avoid Furnace And AC Unit Repairs – Filterbuy air filters in a workshop

    Since every family has different filtration needs, it’s important to ensure you get the right air filter for your home. Filterbuy offers hundreds of sizes, 3 MERV ratings, Odor Eliminator filters, and custom sizing, so you’ll be sure to find what you need. If you don’t know where to start, take our quiz to find the MERV fit for you!


    Evaporator Coil Maintenance

    Like with air filters, evaporator coil maintenance is often neglected. Many homeowners are unaware that you can avoid the need for AC and furnace repairs by regularly inspecting, de-icing, and cleaning your evaporator coils.

    Evaporator coils are an HVAC system part located inside the indoor AC unit. They are responsible for absorbing heat and moisture from the air that flows over them. To keep the coils functioning properly, it’s important to keep dust and ice off of them. Dust can be removed by wiping and scrubbing the coils with a mixture of detergent and water, but removing ice from evaporator coils is more complex.

    Evaporator coils icing over is another common problem that’s usually caused by restricted airflow over the coils, leading to decreases in temperature and condensation on the coils. Over time, the condensation can freeze and cause ice to form over the coils. Dirty air filters, clogged ductwork, or a blower motor malfunction usually cause decreased airflow.

    Low refrigerant levels can also cause evaporator coils to ice over. If you see ice forming on the evaporator coils, it's important to turn off your system and call an HVAC technician. You can de-ice the coils yourself by turning the system off, letting the ice melt, and cleaning the coils, but it’s best to leave this up to the professionals. They can pinpoint the issue and make any necessary AC or furnace repairs. After repairs are complete, regularly change your air filter, schedule annual preventative maintenance, and monitor your refrigerant levels to prevent future AC and furnace repairs.

  3. Electric Control Failure

    Electrical failures are a common cause of AC and furnace repairs. They can cause whole-system malfunctions, reduce efficiency, and create safety hazards. The most common electrical problems include short circuits, electrical overload, thermostat failure, and blower motor failure.

    Furnace Repairs – Exposed wires in a variety of colors

    Electric control failures can be dangerous depending on the situation. If you suspect that an electrical failure is a safety hazard, it’s time to call a professional. Professional HVAC technicians have the proper equipment and training to prevent accidents and the need for further AC and furnace repairs.

    Blower Motor Failure

    Blower motor failure is a common but preventable form of electric control failure. Preventing blower motor failure is an effective way to avoid AC and furnace repairs.

    Blower motor failure is usually caused by restricted airflow. If you forget to change your air filter for an extended period, enough debris can build up to cause your blower motor to fail. Debris buildup in your air ducts can also cause blower motor failure. If airflow is restricted in any way, your motor will work in overdrive to move air through the system. This can cause overheating, burnout, and even fires.

    Blower motors are expensive to replace and install, but there are easy and practical ways to optimize airflow and prevent furnace and AC unit repairs. Be sure to change your air filter at least once every 3 months, get your air ducts cleaned, and regularly get your system serviced.

    Capacitor Failure

    A capacitor stores and releases electrical energy to keep the system running smoothly. When capacitors fail, it can cause a range of issues that can affect your HVAC system’s performance.

    One of the most common symptoms of a failing capacitor is decreased cooling or heating output of the system. This is because the capacitor provides the necessary electrical energy to power the compressor and fan motors. Another symptom of a failed capacitor is a buzzing or humming noise coming from the system. This is often caused by the capacitor failing to provide the necessary electrical energy to the compressor or fan motor, causing them to vibrate and make noise.

    Capacitor failure can also cause the HVAC system to fail completely, as the system will shut down if the capacitor is unable to provide enough electrical energy to keep it running.

    To prevent capacitor failure and other AC and furnace repairs, have your HVAC system inspected and maintained regularly by a professional technician. They can check the capacitor and other components to ensure they are functioning properly and replace any parts that are worn or damaged. Additionally, keeping the system clean and debris-free can help reduce the risk of overheating and electrical issues.

  4. Sensor Problems

    HVAC sensors monitor temperature and humidity levels and communicate with your thermostat. They can malfunction over time, leading to incorrect readings. This can cause the system to operate inefficiently, resulting in higher energy bills and discomfort at home. If the problem goes on long enough, you may even need expensive AC or furnace repairs.

    AC Unit Repairs – Digital thermostat in round shape

    Regularly cleaning your sensors can help prevent inaccuracies. Dust, dirt, and other contaminants can build up on the sensor over time and affect the readings. In other cases, wiring problems can occur. Loose connections, damaged wires, or other issues can affect the performance of the sensor, affecting the readings as well.

    If you suspect that there is a problem with the sensors in your HVAC system, it's important to have them inspected and repaired by a trained technician. This small investment will save you money in the long term, prevent furnace/AC unit repairs, and make your home more comfortable.

  5. Condenser Drainage Problems

    The condenser is the outdoor unit of an air conditioning system, and it is responsible for removing heat from the air. Removing heat produces water as a byproduct, which must be drained away from the system. This is what the condenser drain line is used for.

    One of the most common problems with condenser drain lines is clogging. Dirt, debris, and other materials can accumulate in the drain line, preventing water from flowing out of the system. This can lead to water backing up and damaging your HVAC equipment and home. Drain lines can be unclogged at home using a snake, chemical drain cleaners, a wet/dry vacuum, a plunger, a vinegar solution, etc. However, this task is best left to the professionals to avoid further AC and furnace repairs.

    To prevent future condenser drain line issues, it's important to schedule annual maintenance and inspections for your system. This will nip any problems in the bud and save you thousands of dollars over the years. If you suspect a problem with your condenser drain line, contact a professional HVAC technician to inspect and repair the issue.

How Air Filters Help Avoid Furnace And AC Unit Repairs

Restricted airflow is the cause of many furnace and AC unit repairs. This is why always having clean air filters on hand is important. Regularly changing your air filters helps optimize airflow, increases system efficiency, and prevents furnace and AC unit repairs.

With Filterbuy’s Autoship Subscription program, you’ll never have to run out of air filters again. Changing your air filter is a practical and easy way to care for your home. Homeowners who take this preventative measure can avoid furnace and AC unit repairs, maximize their equipment lifespan, and reduce their monthly energy bills. Take the first step today by finding your air filter size here.

Filterbuy LOCAL offers professional residential HVAC and indoor air quality services if you're interested in other ways to make your HVAC more efficient. Get a free quote for select services here.