When the air conditioning starts acting up or the heat pump isn’t working right, it’s natural to feel a bit lost. HVAC systems are complex, and when they’re not functioning properly, you can easily get uncomfortable and frustrated. 

In this article, I’ll address some of the most common HVAC questions that pop up when things go awry. From mysterious drips to error codes that seem like a foreign language, I’ll cover the bases to help you understand your HVAC systems better and know when it’s time to call in the pros.

Understanding HVAC Basics

Before diving into specific issues, it’s helpful to have a basic understanding of HVAC systems. HVAC stands for Heating, Ventilation, and Air Conditioning. These systems are responsible for maintaining comfortable temperatures and air quality in homes and other buildings.

Parts of an HVAC System

The typical HVAC system has several key components: a furnace or heat pump for heating, an air conditioner or heat pump for cooling, ductwork for moving conditioned air, a thermostat for controlling the temperature, and air filters to improve indoor air quality by capturing dust, pollen, and other airborne particles.

How HVAC Systems Work

HVAC systems work by circulating air through the home, heating or cooling it as needed, and filtering out contaminants. In cooling mode, the system removes heat and humidity from indoor air, while in heating mode, it warms the air to the desired temperature. Adequate air circulation ensures that every room in the home maintains a consistent, comfortable environment.

In cooling mode, refrigerant absorbs heat from the indoor air and releases it outdoors, thus cooling the air inside the home. When the system is in heating mode, it absorbs heat from the outdoor air‌—even in cold weather‌—and transfers it indoors to warm the home.

If you have a fuel-burning furnace, the fuel source combusts and gets distributed through the house through ducts using a blower fan.

Troubleshooting Common HVAC Issues

When HVAC systems malfunction, it can lead to a range of problems. Here are some common issues you might face and how to address them.

Dripping Indoor Units

One of the most common complaints is water dripping from the indoor unit of a ductless split air conditioner during cooling mode. This issue can be worrying, but it’s often easily resolved.

The cause is usually related to the condensation process. As the air conditioner cools the room, it removes moisture, which collects on the cooling coil and drips into a drain pan. From there, it should flow out through a drain hose. If you disrupt any part of this process, it can lead to water leakage.

To address the problem:

  1. Check the drain pan’s slope to ensure proper water flow.
  2. Inspect the condensate pump (if there is one) to make sure it’s working properly.
  3. Clear any blockages in the drain hose.
  4. Clean or replace air filters to improve airflow.

If these steps don’t resolve the problem, it may be time to call in an expert to inspect the system.

Mysterious Error Codes

Modern HVAC system displays often show error codes when something goes wrong. These codes can be confusing, but they help identify specific problems. For example, “E1” might indicate low refrigerant levels, “E2” could signal a disconnected room sensor, and “E7” may point to a thermostat problem.

Your specific system manual should detail what each code means. If it doesn’t, contact the manufacturer or a qualified technician. Regular system maintenance can prevent many issues that trigger error codes.

Unusual Noises and Odors

Sometimes, HVAC systems produce unusual noises or emit strange odors, signaling potential problems. Loose parts can cause odd noises or issues with the blower motor. Musty or burning smells can indicate mold, electrical issues, or overheating parts.

If you smell or hear something strange coming from your HVAC system, turn it off, inspect visible parts for obvious issues, and contact a professional if the source of the problem isn’t immediately apparent.

Energy Efficiency and HVAC Technology

As energy costs rise, you’re probably looking for ways to improve the efficiency of your HVAC system. New technologies offer solutions that can help reduce energy consumption and lower utility bills.

Inverter Air Conditioners

Inverter air conditioners are becoming increasingly popular due to their energy efficiency. These systems can adjust their compressor speed to match the cooling demand, reducing energy waste. Benefits of inverter air conditioners include lower energy consumption, more consistent temperature control, and quieter operation. 

While the initial cost may be higher than that of traditional AC units, the long-term savings on energy bills often make inverter systems a wise investment. Also, these systems can maintain a more consistent temperature by avoiding the frequent AC start-stop cycles.

DC Inverter Technology

DC inverter technology takes efficiency a step further. DC inverter air conditioners can operate at lower voltages, making them even more energy efficient and capable of functioning in areas with unstable power supplies. 

DC inverter air conditioners can work at different speeds, perform better in areas with voltage changes, and save a lot of energy. DC inverters save energy and help HVAC systems last longer by reducing the wear and tear from constant cycling—meaning fewer repairs and less-frequent replacements.

Smart Thermostats

Smart thermostats learn your schedule and temperature preferences to improve ‌heating and cooling cycles automatically. You can control them from anywhere using smartphone apps. They track your energy usage and “learn” to help your system work more efficiently, saving energy and money.

Maintenance and Care of HVAC Systems

Proper maintenance keeps HVAC systems running efficiently and helps eliminate costly repairs. Regular care can extend the life of the system and ensure it operates at peak performance.

Changing Air Filters

One of the simplest yet most important maintenance tasks is changing air filters regularly. Dirty filters can limit airflow, reducing efficiency and‌ causing system failures. Check filters monthly, clean or replace them as recommended by the manufacturer, and consider using high-efficiency filters for better air quality. 

Changing air filters is a quick task that requires little technical know-how. It ensures your system has the airflow it needs to operate effectively and helps maintain better indoor air quality.

Professional Servicing

While you can handle many HVAC maintenance tasks yourself, annual servicing by a qualified technician can catch potential issues before they become major problems. 

A professional service typically includes checking refrigerant levels, inspecting electrical connections, cleaning coils and other components, and lubricating moving parts. Preventive maintenance plans cover all parts of your HVAC system, making sure it’s ready for seasonal heating or cooling needs.

DIY Maintenance Tips

Clean the outside unit, making sure the vents are open, and clean around the indoor air handler often. These simple steps can help keep your system running smoothly between professional maintenance visits.

When To Call a Professional

While you can DIY the solutions to some HVAC problems, others require professional attention. Knowing when to call in an expert can save time and money and prevent system damage.

Signs that it’s time to call a professional include:

  • Persistent error codes you can’t resolve
  • Unusual noises or odors coming from the system
  • Significant changes in energy bills
  • Frequent cycling on and off
  • Uneven heating or cooling throughout the home
  • Thermostat not staying at the correct temperature
Editorial Contributors
avatar for Alora Bopray

Alora Bopray

Staff Writer

Alora Bopray is a digital content producer for the home warranty, HVAC, and plumbing categories at Today's Homeowner. She earned her bachelor's degree in psychology from the University of St. Scholastica and her master's degree from the University of Denver. Before becoming a writer for Today's Homeowner, Alora wrote as a freelance writer for dozens of home improvement clients and informed homeowners about the solar industry as a writer for EcoWatch. When she's not writing, Alora can be found planning her next DIY home improvement project or plotting her next novel.

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Laurie Engle

Expert Writer & Reviewer

Laurie Engle is a freelance writer who provides insights to homeowners on topics such as the home warranty industry, relocation issues, and real estate trends. As a licensed Realtor since 2001 Laurie has acquired extensive expertise in dealing with home warranty companies and navigating the intricacies of the real estate market. In addition to her commitment to helping clients with their home buying and selling needs, she maintains a sharp awareness of market dynamics, including property values, interest rates, and local regulations.

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