You rely on your HVAC system to keep your home comfortable all year long. Your heating and cooling system spends many hours in operation day in and day out, year after year. Even though these systems are built to handle a lot, the reality is, you’ll probably run into a problem eventually.

So, what are the most common culprits for HVAC malfunctions? We’ll break down the top 10 most common reasons for HVAC system problems and show you how proactive maintenance and smart habits can cut down on costly repairs.

It should also be noted that most of these issues can be avoided by having regular HVAC maintenance performed on your system by a professional, saving you money in the long run. Spot these 10 common HVAC problems and troubleshoot like a pro:

  1. Unit Not Turning On

    Causes:

    • Dead thermostat batteries
    • Tripped circuit breaker
    • Wiring issues

    How To Avoid It

    If your thermostat uses batteries instead of being hardwired into your home electrical system, check them regularly, as low power can affect proper operation. Also inspect your circuit breakers periodically to make sure theyโ€™re not tripped. If you suspect faulty wiring is the culprit, call a professional immediately for an inspection and repair.

  2. Poor Airflow

    Causes:

    • Dirty air filters
    • Clogged vents
    • Blocked ducts

    How To Avoid It

    This is the most common HVAC problem. Replace your air filters every 1-3 months to prevent airflow restriction, or more frequently in a dusty environment. Also, remove obstructions like grass, shrubs and limbs from around outdoor units and vents. Consider having your ducts cleaned to remove accumulated dust and debris.

  3. Uneven Temperature Distribution

    Causes:

    • Poor insulation
    • Blocked vents
    • Lack of zoning control

    How To Avoid It

    Reinforce your homeโ€™s insulation where needed, especially around leak-prone areas like windows and doors, and consider installing dampers in your ductwork to allow you to regulate airflow into living spaces more precisely. For larger homes, think about installing a zoned HVAC system for a better temperature control in each room.

  4. Strange Noises (Whining, Squealing or Rattling)

    Causes:

    • Loose components
    • Worn-out fan belts
    • Airflow obstructions

    How To Avoid It

    Of all HVAC maintenance issues, this is among the easiest to address. Keep moving parts well lubricated as per the instructions in your ownerโ€™s manual. Tighten any loose screws or bolts during routine inspections and replace fan belts that look worn or are squealing. Clean or replace air filters regularly to avoid strain on components that could cause noise issues.

  5. HVAC Blowing Hot Air Instead of Cold

    Causes:

    • Dirty air filters
    • Compressor malfunctions
    • Low refrigerant levels

    How To Avoid It

    This is another issue that can be caused by dirty air filters, so clean or replace them when necessary. Hot air coming from your AC could also be a sign of a malfunctioning compressor. Be alert for unusual noises or vibration from the unit. Low refrigerant levels due to a leak may also be the culprit. Ice buildup on coils may indicate low refrigerant. In this case, itโ€™s best to call a professional HVAC contractor for an inspection and repair.

  6. Refrigerant Leaks

    Causes:

    • Corrosion in refrigerant lines
    • Poor installation practices
    • Wear and tear over time

    How To Avoid It

    Regularly check your refrigerant lines for visible leaks or residue. You can use a leak detector, available at hardware stores, or use soapy water for smaller leaks. Scheduling an annual inspection and maintenance can identify potential issues early to avoid costly future repairs.

  7. Air Handler Malfunctions

    Causes:

    • Dirty filters
    • Motor problems
    • Faulty wiring

    How To Avoid It

    Poor airflow through your system is yet another one of those common furnace problems that can be caused by dirty air filters. But it could also be caused by the blower motor malfunctioning due to mechanical failure or faulty wiring. If itโ€™s not a filter problem, you should call your local contractor to check it out โ€” especially if you think your blower is covered under warranty.

  8. Short Cycling (Turning Off Too Quickly)

    Causes:

    • Incorrectly sized HVAC system
    • Thermostat issues
    • Clogged air filters

    How To Avoid It

    A common cause of short cycling is a defective thermostat. Have it inspected and repaired or replaced if necessary. If short cycling persists, especially if youโ€™re in a new home or youโ€™ve made large renovations, check with your contractor to make sure you have the right-size HVAC system for your home.

  9. Pilot Light Issues on Gas Furnaces

    Causes:

    • Dirty pilot components
    • Thermocouple malfunctions
    • Gas supply problems

    How To Avoid It

    Routinely clean around the pilot light area to prevent residue buildup that could interfere with ignition. Make sure gas valves are functioning properly and have a professional inspect the thermocouple during regular maintenance checks.

  10. High Energy Bills Due to HVAC Issues

    Causes:

    • Poor maintenance practices
    • Dirty filters or coils
    • Inefficient components

    How To Avoid It

    Consider installing a programmable thermostat to cut down on energy use by tailoring temperature settings throughout the day. Staying on top of regular maintenance tasks mentioned above, like cleaning coils and replacing filters can significantly reduce energy consumption.

Notice any of these common HVAC problems happening with your system? Contact Apex Air today for a free estimate.

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