7 Common HVAC Problems and How to Fix Them

Thermostats with text: "control warmth with programmable thermostats"

Your HVAC system keeps you warm in the winter and cool in the summer and purifies the air while maintaining comfortable humidity levels year-round. Yet we rarely think about this hard-working and essential equipment until HVAC problems strike. Of course, the best way to deal with the most common HVAC problems is through routine preventative HVAC services and maintenance performed by qualified service professionals. However, some issues can be managed well by the homeowner. Let’s discuss seven common HVAC problems and how to fix them. Always start with the easiest fix first!

Understanding the Basics

Understanding the basics of how your HVAC system works will help you to understand and address common HVAC problems.

Your HVAC system circulates air throughout your home, adding or subtracting heat and removing particulates. To cool your home, the equipment draws in air, passing it over evaporator coils, which are copper tubes filled with refrigerant. The refrigerant absorbs the air’s heat, and the cooled air is returned to your home through the ductwork. Meanwhile, the heat absorbed by the refrigerant is released outdoors. To heat your home, air passes over a heat exchanger to become warmer before circulating back into the house. A heat pump reverses the cooling process to warm the air.

Your HVAC system requires a well-maintained refrigerant flow and unimpeded airflow throughout the system to function efficiently. HVAC problems occur when either of these crucial operations is compromised.

Uneven Heating or Cooling

Uneven heating or cooling in the home is a common HVAC problem with several possible causes. It is also often the easiest to fix. If an air vent is closed or blocked by furniture, that room will not get the airflow needed to fully warm or cool. If all the vents are open and unobstructed, check the air filter. A dirty air filter compromises your HVAC system’s efficiency, leading to uneven air distribution. Replacing the air filter every 90 days (60 days if you have pets) is recommended.

Thermostat Issues

Thermostat issues are among the most common HVAC problems. If the HVAC system won’t turn on or off, causes temperature fluctuations, or loses its programming, it could mean major repairs are needed, but more likely, it’s the thermostat. First things first — check the batteries. Next, review the thermostat settings and make sure they are set correctly. An incorrect setting can cause frequent cycling. Next, open the thermostat housing for a gentle dusting with a soft brush. If you still have issues, conduct a simple calibration test:

  • Set the thermostat 10 degrees warmer or cooler than the current temperature.
  • In one hour, check the air temp coming from the vents with a different device.
  • If the thermostat and the device match, the thermostat is functioning currently, and it’s time to call in your local HVAC professionals.

Airflow Restrictions

If the air conditioner or heater pumps out less air than before, this common HVAC problem likely has an easy fix. Change out the air filters. Go to the outdoor unit and remove any weeds or accumulated debris. Then, check the vents to be sure none are blocked. If none of these actions improve the airflow, the next step is to clean the air ducts. At that stage, it's best to use professional heating and cooling services.

Unusual HVAC Noises

Rattling, whining, or squealing sounds can be a nerve-wracking HVAC problem. It is likely caused by loose nuts, bolts, or screws joining parts of the system. Strange as it might sound, dirty air filters may be the cause. Obstructed airflow forces the equipment to work harder than it should, which can cause fasteners to come loose. Replace the air filters, then look for loose joints, screws, and bolts. If the noise remains and your HVAC system is more than 20 years old, consider replacing the entire system.

Frequent Cycling On and Off

Frequent cycling or short cycling is a common HVAC problem with several potential causes. First, check those air filters. Next, check that the thermostat is working and set correctly. Ensure none of the air vents are closed or blocked. Remove any weeds or debris from around the outdoor equipment, and look through the protective metal grill to the condenser coils. If they appear dirty, hose them off through the grill. If you remove the grill, do not bend the delicate condenser fins.

Refrigerant Leaks

As stated above, proper refrigerant levels and unobstructed flow are essential for the operation of your HVAC system. While a refrigerant leak is a common home A/C problem, it’s not one the homeowner should tackle. The refrigerant circuit is a sealed system, and the EPS mandates that refrigerant fluid should be handled only by licensed, certified professionals. However, you can check for signs of a refrigerant leak to provide accurate info when you call your HVAC repair company. Ice buildup on the refrigerant lines or hissing noises can indicate a refrigerant leak.

Frozen Evaporator Coils

Another common problem with home A/C units is ice buildup on the evaporator coils. This is caused by impaired airflow, low refrigerant, or malfunctioning HVAC components. First, turn off the cooling system to prevent equipment damage. Switch to “fan only” mode to help defrost the coils. Check the air filters and replace them if they are dirty. Check all the air vents to ensure they are open and unblocked. Let the ice melt instead of trying to remove it. If the freezing recurs, contact your local HVAC repair service.

Breathe Easy with Professional HVAC Solutions

Whether you need to install a whole new HVAC system or just want an HVAC tune-up to keep your system running at peak efficiency, trust the pros at Aire Serv®. We address all common HVAC problems — and uncommon ones, too. With locations across the U.S., we’re your local HVAC experts. The Neighborly Done Right Promise backs all our work because no job is done until it’s done right!

Let us help you breathe easier with Aire Serv. Request an appointment today!