While your heating, ventilation, and air conditioning (HVAC) system is a source of great modern comfort for you and your family, it’s not exempted from failure. Serious malfunctions occur because of wear and tear, lack of maintenance, and improper installation. It’s frustrating to know that you need to eventually replace your HVAC or pay a spiking utility bill because of a major problem that should have been prevented in the first place.

It pays to know the warning signs you need to watch out for that indicate your HVAC system needs immediate repair. Continue reading below to find out more.

Rising Utility Bills

If you notice a sudden spike in your utility bills, the major culprit is likely your failing HVAC system. Compare your bill last winter from the most recent, and check the significant difference. If you have not adjusted the thermostat and you’re getting a high bill, it only means that your HVAC system is working double time to cool or heat your home more than it used to.

Don’t delay and contact a trusted and reputable HVAC professional, like Willard Power Vac, to check what’s going on with your HVAC system.

Not As Comfortable As It Used To Be

Your failing HVAC system may have a hard time keeping up your desired level of comfort because of a problem with the blower, not moving to cool or warm the air inside the house properly, or another component issue, causing inefficiency. It’s important to diagnose and fix HVAC problems early before they get worse to avoid costly repairs and HVAC parts or system replacement.

Strange Sounds

While your air conditioner may have a typical operating sound, you should not hear distinct sounds when your HVAC system is running. While you’re used to the usual subtle background noise, hearing any sound changes or strange sounds, like whistling, banging, or metal rubbing is a clear indicator that something isn’t right. You have to call an experienced HVAC technician right away.

Strange Smells

Unusual smells could indicate a dangerous HVAC problem. There are different types of odors depending on the source of the HVAC issue. The problem could be dirty ducts that need cleaning, a wiring problem, or something else. If you notice a strange smell coming from your HVAC, you need to shut it off immediately and call an HVAC repair company.

Here are the unusual smells you might encounter with a malfunctioning HVAC system:

  • Rotten Egg Smell: You’ll notice a slight odor of rotten eggs if your home HVAC system has a natural gas leak. However, the smell shouldn’t be prominent. Leave your home immediately if you suspect any gas leak. Many people die every year because of natural gas explosions. Contact the gas company to inspect your home right away and stay with relatives or friends until the HVAC professional ensures that your home is safe.
  • Burnt Electrical Smell: Like other appliances, your HVAC system might give off a burnt odor when overheating. A malfunctioning or damaged electrical wiring may result in an electrical smell, which could pose a major fire hazard in your home. Turn off your HVAC immediately with the main shutoff and call your local HVAC technician for prompt repairs.
  • Musty or Moldy Smell: Your air conditioning unit generates a lot of moisture inside through buildup of condensation that stays contained inside the unit. But if moisture gets into the unit’s duct system, mold growth quickly develops. An HVAC professional will clean the ductwork, check the source of the moisture leak, and fix the problem to keep you and your family safe.

Water Leaks

Through visual inspection, you’ll determine water leaks, which could mean a broken condensate pump or a frozen evaporator coil. Furnace leaks could mean a clogged drain or damaged condensation line. Water leaks could be a slipping hazard. Also, it provides a suitable breeding ground for mold.

Faulty Heat Exchanger

For a gas-fired furnace, the most critical component is the heat exchanger, which transfers heat to the air via the gas burners, circulating through the system. Heat exchangers tend to crack if the temperature is too hot, expanding beyond design limits. Excessive moisture may also damage the heat exchanger over time.

An HVAC professional will check your furnace to see if the filters are dirty and clean them, or perform major repairs as needed. However, when there are holes or cracks, or if your appliance is already old, replacement is imminent. Any breach in the furnace heat exchanger causes exhaust gases to combine with the circulated air that could result in dangerous carbon monoxide levels inside the house.

Here are the indicators of a bad heat exchanger:

  • Exhaust smell noticeable in your living space
  • Soot around your furnace
  • Soot around the heat registers in your house
  • Water under your heater
  • Corrosion inside the unit


Your HVAC system is vital for the comfort of your family. That’s why any warning sign shouldn’t be ignored. Immediately contact an HVAC company if you notice any of the above symptoms so you won’t have to deal with stressful problems in the future. Of course, regular inspection and preventive maintenance at least once a year is highly recommended.