Why Is My Air Con Not Working? The Ultimate Troubleshooting Guide

If you’re experiencing problems with your air conditioning, don’t worry – you’re not alone. Regular wear and tear and usage can cause many problems, but what are the most common reasons your air conditioner isn’t working?

Blockages, poor installation, faulty circuitry and physical damage are the most common reasons your air conditioner isn’t working. While you can fix some of these issues yourself, some will require professional assistance.

In this blog post, we will explore some of the most common air conditioner problems and provide solutions to help you get your unit up and running again. You’ll learn what you can do yourself to help fix your air conditioner and when it’s time to seek professional air conditioner servicing.

Keep reading for tips on how to troubleshoot your system and get back to comfortable temperatures in no time.

What Are the Most Common Air Conditioner Problems?

Before we get into troubleshooting your air conditioner, let’s first take a look at some of the most common AC problems:

Air Conditioner is Not Turning On
Air Conditioner is Not Cooling or Heating at all
Water Leaks Coming from the Unit
Air Con Cycling On & Off
Circuit Breaker Keeps Tripping
Strange Noises From the System
Bad Smelling Air
Poor Heating or Cooling Air Flow

Why Is My Air Conditioner Not Working?

Here are the top 13 reasons an air conditioning unit will stop cooling or offer poor cooling performance:

1. The Unit Is Physically Damaged

If you can see that your air conditioner is physically damaged, this is likely the reason why it’s not working. If the unit has been hit by a falling object during a storm or installed by an inexperienced technician, the internal components might be damaged and need to be replaced.

2. The Air Filter Is Blocked

If your air filter is dirty, it can block the airflow from your air conditioner, causing it to work less efficiently. A build-up of dust and dirt can also lead to the unit freezing up, which can cause even more problems.

To prevent this from happening, it’s essential to check and clean your air filter regularly. Cleaning the filter 3-4 times a year is a great way to ensure efficient and clean air conditioning in your home.

3. The Thermostat Is Set Incorrectly

If your air conditioner is turned on, but the temperature isn’t changing, it could be that the thermostat is set incorrectly. To fix this, check the thermostat and ensure it’s set to the correct temperature.

4. The Thermostat is Faulty

If the thermostat is set correctly, but the air conditioner unit still isn’t turning on, it could be that the thermostat itself is faulty. The thermostat is responsible for turning the unit on and off, so if it’s not working, you will need a professional air conditioner technician to replace or repair the thermostat.

5. The Circuit Breaker Has Tripped

If your air conditioner won’t turn on and you can’t see any physical damage, the circuit breaker may have tripped. To reset the breaker, flip the switch back to the “on” position.

If the breaker trips again, it’s best to call in a professional technician to take a look and find out what’s causing the problem.

6. The Coils Have Frozen Over

If your air conditioner is running on cool mode but is not blowing any cold air, the unit may have frozen up. This can happen if the air filter is dirty or if the airflow to the unit is blocked.

If you see ice on the coils, turn it off and let it thaw for a few hours. Once it’s thawed, you can turn it back on and see if it’s working properly.

Note that this is different to ‘defrost mode’ which can occur using reverse cycle heating. In that scenario, you should always let the AC unit finish the defrost cycle before switching it off.

7. Refrigerant Gas is Low

If your air conditioner isn’t running properly and it recently had a gas leak repaired, the system could be low on refrigerant. During normal use, air conditioners don’t lose refrigerant, so they don’t need regassing. But if you have a refrigerant gas leak, this can affect the efficiency of the air conditioner and even prevent it from working entirely.

If your air conditioner isn’t working properly after a gas leak repair, or you suspect there’s a leak, contact a professional air con technician. They can not only test for a leak and repair the problem, but also regas your AC unit safely.

8. The Compressor is Damaged

If your air conditioner is making a strange noise, the compressor may be damaged. This is a serious problem that will require the help of a professional air conditioner technician. Loose parts like fan belts can also cause strange noises, but an experienced technician will be able to identify and resolve the issue, no matter what it is.

9. The Air Conditioner Was Poorly Installed

If your air conditioner wasn’t installed properly, it could cause several issues, including poor airflow and decreased efficiency. Poorly quality technicians may have damaged the unit during installation, not connected the ductwork correctly or installed the wrong sized system.

If you suspect that your unit wasn’t installed properly, it’s best to call in a professional air conditioner technician to take a look and fix the problem.

10. There’s an Electrical Problem

If your air conditioner doesn’t turn on, it could be that there’s an electrical problem. This could be anything from a tripped breaker to a faulty wire. If you suspect that there’s an electrical problem, it’s best to call in a professional air conditioning electrician to take a look and fix the problem.

11. The Air Conditioner Is Too Small for the Room

If your air conditioner is turned on, but the room isn’t cooling down, it could be that the unit is too small for the space. This is a common problem that can be easily fixed by upgrading to a bigger unit.

12. The Condenser Is Dirty

If your air conditioner is running but not cooling the room, it could be that the condenser is dirty. The condenser dissipates heat, and it can’t do its job correctly if it’s covered in dirt and debris.

You can clean this yourself if you’re careful; however, a professional technician will be able to clean and reinstall it without issues.

13. The Compressor Is Worn Out

If your air conditioner is more than ten years old, the compressor may be worn out. The compressor is responsible for circulating refrigerant, so if it’s not working properly, the unit won’t be able to cool. This will require a professional technician to replace the compressor.

What Should I Do if My Air Conditioner Isn’t Working?

If your air conditioner isn’t working correctly, follow these steps to get it back up and running again:

Check the Thermostat – The first thing you should do if your air conditioner isn’t working is to check the thermostat. Sometimes, air conditioner issues can just be a result of an incorrect thermostat setting.
Check the Circuit Breaker – If the air con still doesn’t turn on, the circuit breaker may have tripped. Checking the circuit breaker is quick and easy to do, and it can help you avoid paying call-out fees from an air conditioner technician.
Reset the Unit – If the air conditioner is still not working, try resetting it by turning it off and then back on again. This quick step is easy to do and can save you a lot of time and money.
Clean or Replace the Filter – If the filter is dirty, it can block airflow and cause the air conditioner to work inefficiently or even shut down completely. To clean the filter, remove it from the unit and rinse it with water. If the filter is damaged, it will need to be replaced before you use the system again.
Inspect the Air Ducts – If you have a ducted air conditioner, damage to the ductwork can cause your system not to work properly. Ductwork can be difficult to inspect, especially if you don’t have access to your roof cavity. However, unusual noises and large amounts of dirt and debris around the vents can indicate damage to your ductwork.
Check Coils for Ice or Frost – If the coils are frozen, it can block airflow and cause the AC unit to shut down. To thaw the coils, turn off the AC unit and let it thaw on its own. If the coils are covered in ice, you will need to call in a professional air conditioner technician.
Clean the Condensate Drain – If the condensate drain is clogged, it can cause water to build up and damage the coils. To clean the drain, simply remove any debris that is blocking it.
Clean Dirty Condenser & Coils – If the condenser is dirty, it can block airflow and cause the coils to freeze up. To clean the condenser, turn off the unit and remove the grill. Use a brush to clean the coils, replace the grill and turn the unit back on.
Look for Damaged Power Cables or Wires – If the power cables or wires are damaged, it will cause the unit to malfunction. If you suspect that there is a problem with the power cables or wires like if you can hear popping sounds or there’s a burning smell coming from the unit, it’s best to call in a professional air conditioning electrician.
Call a Professional Aircon Technician – If you’ve tried all of the above and your air conditioner still isn’t working, it’s best to call in a professional air conditioning technician. A licensed technician will have the tools and expertise to diagnose and resolve any issue your unit may have.

Malfunctioning Air Conditioner FAQs

How Do I Reset My Air Conditioner?

To reset your air conditioner, turn off the unit and back on again. If the unit still does not turn on, the circuit breaker may have tripped. To reset the breaker, flip it off and back on again.

Why Does My Air Conditioner Sometimes Blow Cold Air on the Heating Setting?

If your air conditioner is blowing cold air while on the heating setting, it’s most likely in defrost mode, which is a setting that automatically turns on when the outside temperature is too cold and freezes the outdoor coils. The defrost mode usually takes 10 to 50 minutes to complete, after which it will return to normal heating. During this time, the air conditioner should be left to run as normal to complete the defrost cycle.

Other reasons your air conditioner heat mode may not be working properly include incorrect mode and temperature settings and potential faults, like a broken thermostat. If the issue doesn’t resolve itself after an hour, try resetting your air conditioning unit. If the problem continues, contact an air conditioning technician to troubleshoot the issue.

There Is Water Pouring From the Outdoor Air Conditioning Unit, Is This Normal?

It’s normal for your air conditioner’s outdoor unit to have some water coming from it, depending on the type of unit. This is because a reverse cycle air conditioner functions by pulling moisture from the air. The condensation should be safely drained outdoors – directly from the outdoor unit when heating, and from the drain pipe when cooling.

However, water dripping from your indoor AC unit or the ceiling isn’t normal. This indicates a problem or fault with your air conditioning system, which can be anything from clogged filters to a compressor failure. Excessive amounts of water from your outdoor unit can also signal your air conditioning is working too hard.

If you’re unsure whether water leaking from your air con is normal, give your local air conditioning specialist a quick call. They’ll be able to help you identify whether you should be concerned or not.

Why Does My Air Conditioner Keep Turning On and Off?

If your air conditioner keeps turning on and off, the unit may be overheating. Cleaning your air filter can help with overheating issues. However, if that doesn’t help, the cycling could be caused by an electrical issue, which will require a professional technician to repair it.

Why Is My Air Conditioner on but Not Cooling My House?

Identifying why your air conditioner isn’t cooling your home is difficult because it can be caused by multiple issues like frozen coils, a blocked condenser, or the unit may just be too small for your home. An air con technician will be able to diagnose and let you know exactly why your unit isn’t working.

Why Is My Air Conditioner Making Strange Noises?

If your air conditioner is making strange noises, it’s possible that the fan belt is loose or that the coils are dirty. This is one of the most common signs that your air conditioner needs servicing, so it’s best to call an air conditioner technician, who will be able to diagnose the problem and fix it quickly.

Should I Turn Off My Air Conditioner if It’s Not Cooling?

If your air conditioner is not cooling, it’s best to turn it off and call in a professional air conditioning technician. They will be able to diagnose the problem and fix it quickly.

If the unit has a serious issue, turning it off straight away can help prevent serious damage to the air conditioner.

Do I Need to Repair or Replace My Air Conditioner?

If your air conditioner is more than ten years old and is frequently breaking down, you should consider replacing it. The general rule of thumb is if the cost of repairs multiplied by the number of years you’ve had the unit exceeds $5,000, you should replace the system entirely.

If you’re noticing that your air conditioner needs to be repaired more than it used to, you’ve likely considered whether it’s best to continue repairing it or replace it completely. The answer to this question depends on several factors, such as the age of the unit, the severity of the problem, and the cost of repairs.

If your AC unit is over ten years old, it’s probably time to replace it. Air conditioning units typically last about fifteen years, depending on the model. So, if your unit is on the older side, it may not be worth repairing it, especially as it reaches that 15-year point.

If the problem with your air conditioner is severe, such as a refrigerant leak or extensive physical damage, it’s probably best to replace the unit. These types of problems are usually expensive to repair and can cause further damage to the unit if not fixed properly.

However, if your air conditioner is only a few years old or needs simple things repaired, like damaged louvres, it’s usually best to have a professional perform the necessary repairs rather than replace it altogether.

Ultimately, whether to replace or repair your air conditioner depends on several factors, and weighing up all of your options before making a decision is important. Replacing an air conditioner can be expensive, but it may be the best option in the long run. Repairing an air con is usually cheaper, but you could be wasting your money trying to fix a unit after a certain point in its usable life.

If you’re still not sure what to do, the best course of action is to call in a professional air conditioning technician. Speaking to a licensed professional is the best way to determine if it’s better to replace or repair your air conditioner.