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How to Know if You May Have an HVAC Emergency

Emergency HVAC repairs are one of those things you hope you never have to deal with, especially during the hottest and coldest days of the year. So, as they say, (and as we say!) prevention is the best medicine. Check out our article on preventing HVAC emergencies before they make you sweat (or shiver). 

Unusual noises, smells, and leaks are often the biggest tip-offs if you have a problem with your HVAC system that needs immediate attention. In this article, we discuss the signs of an emergency that should prompt you to call an HVAC professional right away. We’ll also cover some possible causes for HVAC issues so you can nip them in the bud before they get out of hand!

Noises: Your HVAC is Turning on Too Often, or Making Odd Sounds

Rapid Cycling

Your HVAC system’s cycles–turning on and off to maintain the desired temperature in your home–should be consistent and regular. While cycles can shorten when it’s extremely hot or cold outside, this can also be a sign that something is wrong.

Sometimes rapid cycling can indicate a problem with either the thermostat or the unit itself. A thorough check by an HVAC professional can often target the source of the problem and prevent other issues from cropping up.

Odd sounds

Funny noises are probably the most obvious sign that your HVAC system is struggling. 

  • A rattle could mean an internal part has gotten loose and needs tightening. 
  • A grinding or shrill sound could mean your motor or compressor has a problem.
  • A rhythmic knocking sound could mean something is stuck to the internal fan or that there’s another type of blockage inside your unit. 
  • A normal but overly loud unit could mean there is a blockage in airflow. 

While some of these situations are more urgent than others, it’s important to make sure the noise isn’t a technical issue putting you or your family in danger or doing damage to your unit if it continues. If you hear odd noises, get it checked by an HVAC professional as soon as possible

Vents: Hot or Cold Air, Smelly Air, or No Air Coming Out 

Air is the Wrong Temperature

When the AC is on, the air should be cool, not warm or hot. Likewise, when your heater is going, you naturally expect warm air, not cold. The following are some reasons your air may not feel right.

  • dirty filters, 
  • lack of airflow, 
  • electrical issues, 
  • a thermostat issue, 
  • evaporator coils that have frozen… among others. 

If you notice an air temperature problem, you might consider checking the thermostat temperature and turning it up or down to see if your HVAC system responds as it should. If the air does not adjust correctly, you should call an HVAC professional.

Smelly air

If there is a bad smell in your home, sniffing your vents can help you determine whether it is coming from your HVAC system. Here are a few of the smells you might encounter if your HVAC needs attention.

  • A burning smell could indicate an overheating motor, a potential fire, or a melted part inside the system. 
  • A mildew smell could indicate mold growing somewhere inside your HVAC system or your vents. 
  • Rancid smells could indicate a rodent or small animal has gotten inside the unit or vents and died. 

If you think there’s a possibility the odor is coming from your HVAC system, and especially if it’s a burning smell, it’s best to turn off your system. Get a professional in quickly, so you can get to the bottom of the issue before more damage is done.

Poor Airflow

No air or lack of airflow coming from your air vents is another sign to watch for. This could be: 

  • a clogged fan or loose fan belt
  • motor issues
  • a clogged air filter
  • uneven temperature around the house

Regardless of the cause, reduced airflow is another sign that requires immediate attention. Poor airflow can dramatically reduce efficiency and damage your system if not dealt with promptly. Get an HVAC company on the phone as soon as possible to resolve the issue and restore your comfort.

Leaks: Ice or Water Where it Shouldn’t Be

A visibly frozen HVAC unit, or a unit with leaking and pooling water, can be indicators of:

  • dirty air filters or coils
  • refrigerant leaks
  • or blocked airflow

If your system has frozen over, continuing to run it can cause bigger problems– like breaking the most expensive parts of the unit and needing an entire HVAC unit replacement. While leaking or even freezing aren’t uncommon, they are issues that need immediate attention to avoid further damage.

Your best course of action if you notice ice or water is to turn off your HVAC system and call an HVAC professional.

Is it an Emergency or Not?

Sounds, smells, poor airflow, leaks, and freezes… these are indicators that something has gone wrong, but is it an emergency?

Will your entire system be compromised or will your house burn down if you don’t get someone in ASAP to check it out?

Because it’s not possible to answer these questions or diagnose the issues without a professional assessing your HVAC unit, it’s best to err on the side of caution. 

If your HVAC system shuts down or you smell burning or otherwise unbearable odors, paired with temperatures outside that require heating or cooling, this certainly would be considered an HVAC emergency. If you can, turn off your HVAC unit and make the call to a professional right away.

Call us 

Exxel Mechanical serves a wide area of central Maryland from our home base in Mount Airy. Our reputation in this area precedes us, as we pride ourselves on placing our customers as our highest priority. This means we not only care about saving you money, but we also care about your safety. If you think you have an HVAC emergency, call us immediately and we will send someone out to check on your HVAC system!  Call us today at (443) 821-1040 or email