Why is my air conditioner not cooling?

24 February 2026

When it’s hot outside and your home feels warm and sticky, few things are more frustrating than realising your air conditioner isn’t cooling properly. It’s one of the most common questions we hear during summer, “Why is my air con not cooling?”

The good news? In many cases, the cause is something simple and fixable. Here are the most common reasons your air conditioner may not be cooling, and what you can do about it.

1. Dirty filters are restricting airflow

One of the biggest culprits behind an air con not cooling properly is dirty or clogged filters.

Over time, dust and debris build up and restrict airflow, making it harder for your system to push cool air into the room. This can make your air conditioner work overtime without delivering results.

What to check:

Reduced airflow from vents
Rooms taking longer to cool
The system running constantly

Cleaning or replacing filters regularly can make a noticeable difference, especially during peak summer use.

Regular maintenance helps identify small issues early, improves airflow and performance, and reduces the risk of unexpected breakdowns when your system is under the most strain. It also helps extend the life of your air conditioner and keep running costs down.

This is something our team can help with. A professional service gives you peace of mind that your system is operating as it should before minor problems turn into major repairs.

2. The settings aren’t quite right

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It sounds obvious, but incorrect settings can often be a common cause.

If your system is set to fan mode or a higher temperature than you realise, it may be circulating air without actively cooling it.

Quick tip: Make sure your system is set to cooling mode and aim for a temperature between 24–26°C for comfort and efficiency.

3. Your outdoor unit is struggling

Your outdoor unit plays a critical role in removing heat from your home. If it’s blocked, dirty, or exposed to excessive heat, your system’s cooling performance can drop.

Common issues include:

Leaves or debris blocking airflow
Dirt build-up on the unit
Poor ventilation around the system

Keeping the area around your outdoor unit clear helps your air con work the way it’s designed to.

4. Low refrigerant or mechanical issues

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If your air con is not cooling despite clean filters and correct settings, the issue may be more technical.

Low refrigerant levels, worn components, or internal faults can all impact cooling performance. These problems aren’t always obvious at first but can worsen quickly if left unchecked.

This is where professional diagnosis becomes important, guessing can often lead to bigger issues down the track.

5. Your system is under strain

On very hot days, your air conditioner has to work harder to maintain a comfortable temperature. Turning it on early, before your home heats up, can help reduce strain and improve cooling efficiency.

If your system struggles every summer, it may also be undersized for the space or due for a service.

When to call in a professional

When to call in a professional

If your air conditioner isn’t cooling, and basic checks haven’t solved the problem, it’s time to get it looked at properly.

At Level Electrical + Air Maitland, we help homeowners and businesses across the Hunter identify why their air con isn’t cooling and recommend the best solution, whether that’s a service, repair, or system adjustment.

We believe in clear advice, practical solutions, and helping you make informed decisions based on your needs and budget.