6 common air conditioner problems

Air conditioner repairing by technician

It can be hard to keep your cool when your air conditioner is on the fritz, especially if it happens in the peak of summer. Luckily, understanding the warning signs for common AC problems can help you address issues promptly before more serious and costly repairs are required. When left unattended, air conditioning problems can quickly get out of hand, often leaving you with a unit beyond repair. More importantly, some of these common problems can negatively affect your health as well. In this article, we’ll go over a variety of common home AC problems and how to spot them. From low airflow and dirty air filters to strange noises and musty smells, keep your eyes peeled for these universal AC problems.

Low airflow

Hands hold air conditioner filter during equipment cleaning
Photo: Adobe Stock/Piman Khrutmuang

Decreased airflow coming from your AC unit is an obvious sign that something is wrong. And while there are several possible causes to explain the inadequate airflow, many of them are issues you can fix on your own. Some common causes of low airflow include:

  • Dirty air filters not only reduce airflow, they can also lead to hefty energy bills as your AC unit works double time to keep up. If you pull out your air conditioner filter and find it covered in thick grdust, it’s time for a cleaning. To clean your filter, first ensure that the air conditioner unit is turned off. Next, remove the filter (or filters) and use a hand-held vacuum to blow away Then, use a microfibre cloth to gently remove fine dust. Finally, give your filter a bath in equal parts hot water and vinegar. Let the filter(s) dry completely before reinstalling.
  • Dirty evaporator coils can occur when you run your AC with clogged air filters or no air filters at all. Since the evaporator coils are responsible for cooling and pushing air throughout your home, dirty coils could constrict airflow. If this is the case, youll need to book a professional to clean the coils.
  • Leaky or clogged air ducts can significantly reduce the amount of cold air being pushed through your vents. And although common, duct leaks and clogs are best handled by an HVAC professional. Improper installation or ductwork that is too small can also restrict airflow.
  • Fan issues, including too much dirt on blades or a problem with the fan’s blower motor also contribute to low airflow.

AC isn’t blowing cold air

Hand holding a remote to adjust the temperature of an air conditioner unit
Photo: Adobe Stock/Astrosystem

When air conditioners stop blowing cold air all together, it’s a sure sign of trouble. If you notice more of a warm breeze coming from your AC unit, there are a few possible causes to look for.

  • Check your thermostat The explanation for warm air in your air conditioning unit may be as simple as changing your thermostat settings. If the settings are all where they need to be, there could be an issue with your thermostat sensor or you might be overdue to change your thermostat batteries. Worst case, you may be dealing with a broken thermostat that needs professional repair.
  • Check your condenser unit The condenser coils are responsible for releasing hot air outdoors. When they are clogged or dirty, hot air gets trapped, causing your AC to push warm air indoors. The clog, in this case, may just be a buildup of leaves and other debris surrounding your outdoor unit.
  • Low refrigerant levels This will have a negative impact on your unit’s evaporator coils which, in turn, can cause warm air and restricted air

AC not turning on

If your air conditioner isn’t turning on, don’t push the panic button. This doesn’t necessarily mean you’re dealing with a broken air conditioner. Before you go comparing new HVAC unit costs, look for the following signs of trouble:

  • Tripped circuit breaker
  • Outstanding issues with evaporator or condenser coils
  • Clogged drain lines
  • Emergency switch is set to “off” on the outdoor unit
  • Installation issue
  • Motor failure
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Weird noise

Unusual or loud noises from your air conditioner are more than just an annoyance–they’re likely a sign of a serious electrical issue. Now, AC units aren’t silent so hearing a light whooshing sound or a click when the unit first turns on is normal. But if you hear hissing, screeching, banging, rattling or excessive clicking, it’s time to contact an HVAC professional. If there’s an electrical smell coming from the AC, immediately turn it off and wait for your air conditioner repair specialist to arrive.

Refrigerant leak

Air conditioner technician using manifold gauge checking refrigerant for filling home air conditioning unit
Photo: Adobe Stock/Eakrin

AC refrigerant is an essential aspect of any air conditioner unit. In simple terms, it’s a chemical that, in tandem with the compressor and condenser/evaporator coils, helps turn hot air into cold. A refrigerant leak can lead to reduced airflow, lack of cooling ability and higher energy bills. If you’re not sure how to spot a refrigerant leak, look for these telltale signs:

  • AC is running longer cycles than usual
  • Evaporator coils are freezing
  • Warmer indoor temperature
  • AC has a water leak
  • Bubbling water sounds
  • Strong refrigerant smell

Leaky refrigerant, sometimes called freon or coolant, is bad for the environment and your health. If you suspect a leak, turn off your AC and immediately call a repair specialist. 

Too much dust

Room air ventilation grill near ceiling
Photo: Shutterstock/Tete_escape

Air conditioners rely on clean and clear airways to push cool air throughout your home. So naturally your AC won’t perform as intended when there is dust blocking that airflow. Dust build-up is normal but easy to avoid with regular cleaning. Remember to regularly change your air filters and clean your AC ducts to avoid performance issues.

The risks of defective air conditioning

Technician using vacuum cleaner to clean air conditioner unit
Photo: Shutterstock/BaLL LunLa

Understanding basic air conditioner problems and solutions might not be at the top of everyone’s priority list but knowing when something is wrong with your air conditioner could help you avoid certain health risks. When left unattended, common AC problems could lead to:

Breathing problems

Your HVAC unit helps clear pollutants from the air. But when dirty air filters are not regularly cleaned, it can trigger asthma and other breathing issues. More serious breathing and health dangers can also occur when a refrigerant leak is left too long.

Allergies

Your AC unit circulates different pollens and pet dander through the air, which can trigger allergies if you have them. Additionally, if there is mould hiding somewhere inside your unit, the AC will blow that into the air as well. To avoid triggering an allergic reaction, keep up with regular cleaning of your home and air conditioner. Pairing your AC with an air purifier can also help.

Cost increase

We get it, the cost of air conditioner repair may seem daunting at first. However, when you let your dysfunctional AC unit continue running without service you’ll soon feel those costs on your energy bill. It’s best to tackle any issues ASAP to avoid higher bills down the line.

Call on specialized contractors

Between steep energy bills and risks to your health and the environment, it’s never smart to delay an AC replacement or repairs. While some repairs are easy to DIY, others require professional help. And that’s where RenoAssistance steps in. We’ve spent years carefully inspecting and verifying our wide network of HVAC contractors. It takes just a few easy steps, to assess your project and then we’ll put you in contact with the best contractor for the job. So don’t wait for your unit to conk out, contact us today and receive up to three quotes for your AC repair.

Amber VanWort is a freelance content writer with a degree in journalism from Durham College. Amber’s work has been published in Narcity, Chicago Tribune, The Belleville Intelligencer, Best Reviews, and more. Her passions include food, travel, and real estate. When she’s not busy meeting her client’s expectations, you can find Amber in the kitchen, elbow-deep in a bag of flour.