Is your air conditioner failing to cool effectively? Find out why and how to fix it
Here we'll explain the most common causes, how you can fix your air conditioner yourself, and when it's best to call out a service technician.
Summer arrives, temperatures rise, and, just when you need your climate control system most… you realise that your air conditioning isn't cooling properly. This common and frustrating situation can be caused by a variety of issues, from simple problems that are easy to fix to those requiring a more thorough technical inspection.
Possible reasons why your air conditioning isn't cooling properly
Before assuming you’ve got a major breakdown on your hands, it's best to check some common issues that might be affecting performance. Here are the main causes:
1. Dirty filters
This is one of the most common issues. Over time, the air conditioning filters build up dust, pollen, and particles, making it harder for air to pass through. If the filters are blocked, airflow is reduced and the appliance simply can’t cool the room.
2. Wrong mode or incorrect configuration
It may sound obvious, but sometimes the problem is simply that the unit is set to fan or heat mode, or the temperature is set too high. Simply checking the remote control might save you from calling out the service technician unnecessarily.
3. Loss of refrigerant gas
The refrigerant gas is responsible for absorbing heat from the indoor air. If there’s a leak, then the unit loses its cooling capacity. This is a delicate issue that always requires professional assistance.
4. Electrical or thermostat problems
A thermostat fault or electrical supply issue can stop the compressor from working properly, directly affecting cooling capacity.
5. Outdoor unit obstructed or dirty
The outdoor unit expels heat to the outside. If it is dirty, obstructed, or exposed to direct sunlight without adequate airflow, it won’t be able to do its job effectively.
6. Fault in the compressor or electronic board
Although less common, a fault in the system’s core components (such as the compressor or electronic board) can cause the air conditioning to stop cooling. In such cases, only a specialist service technician can diagnose and repair the problem.
How to identify the problem step-by-step
Now that you know the most common issues, here’s how to perform a basic initial check before calling out a service technician. Follow these steps:
1. Check the remote control and mode settings
Ensure the unit is set to Cool mode and the temperature is at least 5°C below the current room temperature.
2. Check to see if the compressor starts up
Listen for any noise from the outdoor unit. If it doesn’t start shortly after switching on the system, there may be an electrical or refrigerant issue.
3. Check the airflow
Hold your hand in front of the indoor unit. If hardly any air is coming out, or if it comes out at room temperature, the filters may be obstructed.
4. Inspect the filters
Carefully open the indoor unit and check the condition of the filters. If they’re clearly dirty or full of dust, clean them.
5. Check the area around the outdoor unit
Is it obstructed by flower pots, awnings, or dry leaves? Does it receive excessive direct sunlight without adequate ventilation? Ensure that air can flow freely around it.
Maintenance you can do yourself when your air conditioner is not cooling properly
Proper maintenance not only extends your system’s lifespan, but also helps prevent many problems before they arise. Here are the basic tasks you can easily do yourself:
Clean the filters
It’s advisable to clean the filters once a month during peak season. Simply remove them, vacuum them by hand, and wash with lukewarm water and mild soap. Leave them to dry completely before putting them back in.
Clean the outside of the units
Wipe the casing of the indoor unit with a soft cloth and, if it’s safe to do so, inspect the outdoor unit, removing any leaves, dirt, or debris. Avoid using a pressure washer.
Check the remote controls and batteries
It may seem trivial, but sometimes the issue is simply that the remote control's batteries are flat or the settings have been lost.
Ventilate the space
Ensure the vents are not blocked by curtains or furniture, and air the room during cooler parts of the day to help your system work efficiently.
When to contact the technical service
If your air conditioner still isn’t cooling properly after these checks, it’s time to contact a professional.
Clear signs you need technical support:
The unit turns on but only produces warm air.
You notice unusual noises or vibrations.
There is a leak or excessive humidity.
Electricity consumption has shot up unexpectedly.
The remote control is unresponsive, or the display shows error codes.
Why is it important to always use an authorised agent?
Because only official service technicians are familiar with every model inside out, have genuine spare parts and specialised tools, and adhere to the brand’s quality and safety standards. With Daikin, this ensures a fast, effective service with complete peace of mind.
The added value of Daikin’s after-sales service: Stand By Me
Having a Daikin system is a mark of quality and peace of mind. And much of that peace of mind comes from the exclusive Stand By Me after-sales service, designed so you don’t have to worry about a thing once the system is installed.
What is Stand By Me?
It’s a free online platform for Daikin users, where you can register your product and access all after-sales services in one place.
Benefits of registering:
Extended warranty up to 5 years (depending on the model).
Direct access to the official technical service.
Service history and follow-up.
Notifications for recommended checkups.
Access to manuals, videos, and personalised tips.
Special offers and exclusive benefits for registered customers.
Why is it important to register?
Because it's the simplest way to keep your system in optimal condition, prevent unexpected breakdowns, and receive priority service if anything goes wrong. Registering also helps extend your system’s lifespan and maintain its energy efficiency year after year.
Conclusion: don't let the heat catch you off guard.
If your air conditioning isn’t cooling properly, it's important to be methodical: check the basics, carry out some quick maintenance, and contact the technical service if necessary. In most cases, the problem can be resolved quickly... as long as it’s spotted in time.
And if your system’s a Daikin, remember that you’ve got a whole ecosystem of support behind you. Because we don’t just design high-performance products: we ensure they continue working as well as the day they were installed.
Is your air conditioner failing to cool effectively? Now you know what to do.