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Reasons Your Air Conditioner Isn’t Cooling

An air conditioner keeps your house cool and comfy. Sometimes though, it might stop cooling like it should. This article will talk about why that happens. Dusty filters or a bad thermostat can cause trouble.

Your AC might be too small for your room, or maybe it’s leaking the special gas that makes the air cold. We’ll also look at how to take care of smells from your AC without being too technical.

In 2019, many people talked about these problems online – over 484k shared a discussion on May 29! Big companies like Nirvana Being know how important fixing an AC is for both cool air and saving power bills.

Cooling issues have lots of causes which we can check and fix one by one. And if there’s ice on your coils or you smell something odd, don’t worry; we’ve got solutions for those too.

We’re here to help make sense of why your AC isn’t doing its job and what you can do about it! Join us to learn how to get back to chilling in no time.

Common Reasons Why Your Air Conditioner Isn’t Cooling

There’s a handful of culprits behind why your air conditioning unit may fail to deliver that cool relief. Identifying these common issues is the first step in restoring your indoor oasis to its optimal chill.

Faulty Thermostat

A faulty thermostat can mean your air conditioner doesn’t know when to cool. It might not turn on at the right time, or it could shut off too soon. If your room stays warm, even though you’ve set a cool temperature, check the thermostat first.

Thermostats may need new batteries or a quick reset to work properly again. Sometimes they break and need replacing by an expert. Make sure nothing blocks your thermostat like furniture or curtains as this can also cause problems with reading the correct temperature.

Congested Filter

Moving on from thermostat issues, a congested filter is another common culprit when your air conditioner struggles to cool your space. Dirt and dust can block filters easily. This stops the airflow and makes it hard for your system to circulate cool air.

You should clean or replace your air conditioning system’s filter regularly to keep things running smoothly.

A clogged filter not only hinders cooling but also puts extra strain on your HVAC system. Over time, this can lead to bigger problems like frozen evaporator coils or even a faulty compressor.

To prevent these issues, vacuuming the filter or getting a new one might be necessary, especially if you’ve noticed poor airflow lately. Remember that good maintenance keeps your AC unit efficient and effective at keeping indoor air cool and fresh.

Ice Buildup

Ice buildup can stop your air conditioner from cooling. This happens when the coils get too cold and ice forms on them. If you see frost or ice, turn off your AC to let it thaw. After it melts, check if there’s still an issue.

If the problem continues, the airflow might be weak or a refrigerant leak could be causing trouble. A professional can fix leaks and make sure your refrigerant levels are correct. Next, take a look at “Dirty Condenser” for more ways to help your AC cool better.

Dirty Condenser

A condenser full of dirt hinders your air conditioner’s ability to cool. Dirt and debris block the condenser coils, stopping heat from escaping your home. This makes your AC work harder, cutting down its cooling power and energy efficiency.

Think of the condenser as a radiator for your AC; it needs clear space to release heat from inside.

You should keep plants, leaves, and other items away from the condensing unit outside. Clean off any visible dirt with a gentle brush or hose but be careful not to damage the delicate fins on the coils.

Regular maintenance is crucial for keeping everything running smoothly and avoiding problems with cooling performance.

Next up, let’s explore what happens when there’s a refrigerant deficiency or leak in your system.

Refrigerant Deficiency or Leak

Your air conditioner needs refrigerant to cool your home. Refrigerant is the liquid that absorbs heat from inside your house and releases it outside. If there’s not enough, your AC can’t pull as much heat away, causing it to blow warm air or no air at all.

Leaks in the system lead to a drop in refrigerant levels which means less cooling power.

To fix this problem, you must find and repair leaks in the copper tubing where refrigerant flows. Professional HVAC technicians have tools to locate leaks and seal them up properly.

They will then refill the system with the right amount of refrigerant gas so that your central air conditioning can get back to keeping your space cool and comfortable.

What to Do if Your Aircon is Not Blowing Cold Air

If your aircon is failing to deliver that refreshing chill, it’s critical to take a proactive approach towards diagnosis and repair. Undertaking a systematic check can uncover common issues, guiding you through simple steps aimed at restoring optimal performance to your cooling system.

Check Thermostat Settings

Sometimes, a simple fix can get your air conditioner working again. Checking the thermostat is a great first step.

  • Make sure the thermostat is set to ‘cool’ mode. This tells your AC to start cooling your home.
  • Check the temperature setting. It should be lower than the current room temperature for the AC to kick in.
  • Ensure the fan setting is on “AUTO”. This makes sure that your aircon only blows air when it cools it down.
  • Replace old batteries if your thermostat is not wired directly into your home’s electrical system. Weak batteries might cause issues.
  • Look at the circuit breakers connected to your HVAC system. Reset them if they have tripped.
  • Clean the thermostat if you see dust inside. Carefully remove the cover and gently clean with a soft brush.

Inspect the Filter

Your air conditioner needs a clean filter to work well. A dirty filter can stop your aircon from cooling your home.

  • Turn off your air conditioning system before you do anything else.
  • Find the filter. It’s usually in front of the air handler unit or inside the furnace cabinet.
  • Slide out the filter and look at it closely. If you see lots of dust and dirt, it’s time for a clean.
  • Use a vacuum cleaner gently to remove loose dust from the filter.
  • If your filter is very dirty, you might need to replace it with a new one.
  • Check if your air conditioner’s manual has guidelines on cleaning or replacing the filter.
  • After cleaning or changing the filter, place it back correctly into its slot.
  • Make sure that the arrows on the frame of the filter point in the right direction; this shows airflow direction.
  • Now, turn on your AC and see if there is an improvement in cooling.

Clean Dirty Condenser

A dirty condenser can block cool air from coming out of your AC. Here’s how to clean it:

  • Turn off the AC and find the condenser unit outside. It’s usually a big metal box with sides that look like grills.
  • Remove any leaves, grass, or debris around the unit. These can block airflow and make it harder for your AC to work.
  • Take off the protective grilles or cover from the condenser. Be sure to put all screws in a safe place so you don’t lose them.
  • Use a soft brush to gently clean any dirt off the fins. Don’t press too hard – they can bend easily.
  • Spray through the fins with a garden hose on a gentle setting. Don’t use a pressure washer; it could damage the fins.
  • Check inside for any debris like leaves or twigs and remove them carefully.
  • If fins are bent, straighten them with a fin comb from your local home improvement store.
  • Replace the grilles or cover and secure all screws back in place.
  • Turn your AC back on and let it reach its full cooling potential.

Fix Potential Leaks

After cleaning the condenser, you may still have issues if there are leaks in your system. Leaks can stop your air conditioner from cooling properly.

  • Arrange a professional inspection if you suspect a refrigerant leak. Only trained technicians should handle refrigerant gas because it requires care and expertise.
  • Turn off the power before you check for leaks. Always put safety first, especially with high voltage appliances like air conditioners.
  • Look at the connections and valves for signs of leakage. Use soap water to help spot any escaping gas; bubbles will form where there’s a leak.
  • Seal minor leaks with the right type of sealant. This is a temporary fix until a technician can perform a permanent repair.
  • Replace damaged or worn parts that might cause leaks. Sometimes tubes or coils need replacing to prevent gas from leaking out.
  • Schedule regular AC maintenance and tune-up sessions. Experts recommend this to keep everything running smoothly and leak-free.
  • Monitor your AC after repairs to ensure no new issues arise. Check its performance regularly, especially during peak usage times.

Dealing with Bad Smells When Your Air Conditioner Isn’t Cooling

Bad smells from your air conditioner can be annoying. They often mean there’s a problem inside the unit. For instance, a dirty filter might trap odours and block cool air. Change the filter to see if that gets rid of the smell and helps your AC cool better.

Mould or mildew could also cause nasty smells. These can grow when moisture doesn’t drain properly. If you suspect mould, it’s important to clean it up fast. You might need a professional like Hydes to help clean your system and fix any damage.


Your air conditioner keeps you cool and comfy. When it doesn’t, check for simple problems like a dirty filter or incorrect thermostat settings. Sometimes, it’s a bigger issue like a refrigerant leak or a broken compressor.

Remember to clean filters and coils regularly to help your AC run better. If trouble persists, consider calling in an expert for an AC tune-up or repair.


1. Why isn’t my AC cooling my home properly?

Your AC might not be cooling because it needs a tune-up, has blocked ductwork, or there’s an issue with the refrigerant gas needed for heat transfer.

2. What should I check if my air conditioner is on but not cooling?

Check if your air-con filters are clean and ensure there’s no buildup of ice around the coils. Also, see if the refrigerant levels are adequate.

3. Could humidity affect how well my split system air conditioner works?

Yes, high humidity can make your split system work harder to cool your space and might cause it to seem like it’s not cooling effectively.

4. How do mini-split ACs differ from standard ACs when they’re not cooling?

Mini-splits often have separate issues such as improper settings or blocked external units that may prevent them from cooling correctly compared to traditional ACS.

5. Is it only the heat pump in the air cooler that affects cooling ability?

No, while a faulty heat pump can impact an air cooler’s efficiency, other factors like dirty filters or leaking refrigerant also play crucial roles.

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