Common HVAC Problems and How to Prevent Them

HVAC Logo IconBy Tom MoorNovember 29, 2023

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Despite best efforts, your HVAC system is bound to develop issues over time, especially when it’s pushed to the limit during extreme weather conditions. To avoid common HVAC problems, it’s critical to invest in regular maintenance and contact a reputable HVAC contractor when issues first develop.

Keep reading as HVAC.com, your trusted advisor for all things HVAC, discusses 8 of the most common HVAC problems and how to prevent them.

The Most Common HVAC Issues

1. Dirty or Clogged Filters

dirty or clogged HVAC air filter is one of the most common HVAC issues – and also one of the easiest to prevent. Swapping out air filters every 2-3 months is recommended, or according to the manufacturer’s guidelines. Dirty filters restrict airflow into your HVAC system, which can cause several issues including inadequate airflow, high energy bills, unnecessary strain on system components such as the blower, and potential overheating, which will shut your HVAC system down completely

2. Malfunctioning Thermostat

When your furnace or air conditioning system isn’t operating properly (or at all), the culprit may not be the system itself, but an issue with the thermostat. A malfunctioning thermostat can cause an HVAC system to turn on and off erratically, or shut down completely. Refer to your owner’s manual to ensure the thermostat is set up correctly, and check if the batteries need to be replaced. If the thermostat is still malfunctioning, contact an HVAC contractor to inspect it.

3. Blown Fuses and Tripped Circuit Breakers

Blown fuses or tripped circuit breakers are common when your heating or cooling system runs almost constantly during extreme weather events. A clogged air filter can also cause this HVAC issue because the system must strain to reach the set temperature. Replace the filter to see if it resolves the issue; if not, contact an HVAC technician to inspect further.

4. Water Leaks

Are there puddles around your HVAC system? In most cases, a clogged condensate drain line is at fault. When your air conditioner pulls excess humidity from the air during the summer, the water droplets collect in a drain pan before being funneled outside through the drain pipe. A clogged condensate drain pipe can cause water to spill out onto the floor, potentially leading to damage and mold.

5. Refrigerant Leaks

Refrigerant is a necessary component of every central air conditioning and heat pump system. When a refrigerant leak develops, you may notice warm air blowing from your vents, a hissing sound, or a frozen evaporator coil. Refrigerant can be dangerous to handle, so contact a reputable HVAC contractor to recharge the refrigerant.

6. Unusual Noises

An HVAC system making strange or loud noises is cause for concern and should be inspected by a trustworthy HVAC technician. Banging or rattling noises could indicate a loose or broken part, while a hissing sound can signal a refrigerant leak. Other common noises include screeching, clicking, and rattling which indicate some type of HVAC issue that should be inspected.

7. Dirty Coils

Your cooling system’s indoor evaporator coil is tasked with absorbing heat from the indoor air. When the coil is covered in dirt and debris, it can’t operate effectively and cool your home, leading to ineffective cooling, longer cycles, and higher energy bills. A professional HVAC contractor cleans the evaporator coil during routine maintenance.

The condenser coils in an air conditioner or heat pump can also become dirty over time, leading to issues. The condenser coil is responsible for releasing heat outside. When the condenser coil gathers dirt and debris, the system will not operate properly, leading to high energy bills, ineffective cooling, and poor indoor air quality.

8. Poor Airflow

Poor airflow is one of the most common HVAC problems. Common culprits of poor airflow include clogged air filters, obstructed condenser units, blocked vents, thermostat issues, refrigerant leaks, and dirty coils. A technician can uncover the cause of this HVAC issue and make a timely repair to prevent issues such as inadequate airflow, high energy bills, and increased wear and tear.

How to Prevent Common HVAC Problems

While HVAC systems may develop issues over time regardless of how well they’re cared for, you can limit the problems and prevent more serious damage from occurring by:

Performing Regular Maintenance

Regular HVAC maintenance is key to a properly functioning system. HVAC tune-ups should be performed twice a year; once before the cooling season and again before the heating season.

During an HVAC maintenance appointment, your HVAC contractor will clean, calibrate, and lubricate all necessary components, as well as inspect the system to catch any minor issues before they balloon into bigger, more expensive HVAC problems down the road. Almost every issue mentioned above can be prevented through regular maintenance.

Making Timely Repairs

If you notice a slight noise or a small leak, it’s often human nature to wait until the issue becomes worse before contacting a professional. However, the quicker you have the HVAC issue properly identified and repaired, the less damage it will cause.


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