If your air conditioner is running but the air coming out feels warm, work through the simple checks first.
Sometimes the cause is something you can fix in a few minutes. Other times, warm air is a sign that the system needs professional attention.
Here is the order we recommend checking things in.
Step 1: Check the Controller
Start with the obvious.
Make sure the system is set to Cooling mode, usually shown by the snowflake symbol, and that the set temperature is below the current room temperature.
If it has only just been switched on, give it a few minutes to begin cooling properly.
If the settings are correct and the air still feels warm, move to the next check.
Step 2: Check the Filters and Airflow
Dirty filters can restrict airflow and reduce cooling performance.
For split systems, check the filters behind the indoor unit. For ducted systems, inspect the return-air filter.
Also make sure supply vents and return-air grilles are not blocked by furniture or storage.
Clean the filters according to the manufacturer’s instructions, then test the system again.
If airflow is still weak, there may be another issue inside the system.
Step 3: Look for Ice or Frost
If you can see ice or heavy frost around the indoor unit, switch the system off and let it thaw.
Do not scrape the ice off or keep running the air conditioner.
Icing can be caused by restricted airflow, but it may also point to a refrigerant or internal system fault.
If the ice comes back after the filters and airflow have been checked, stop there and book a technician.
Step 4: Check the Outdoor Unit
The outdoor unit needs clear airflow to release the heat removed from inside your home.
Make sure it is not blocked by leaves, garden growth or stored items.
If the outdoor fan is not running, the unit is making unusual noises or there is obvious damage, switch the system off.
That is the point where further DIY troubleshooting is not worth the risk.
Step 5: If It Is Still Blowing Warm Air, Stop Troubleshooting
If the controller is set correctly, the filters are clean, airflow is clear and the system still will not cool, the problem may be deeper.
Possible causes can include refrigerant loss, coil issues, electrical faults, controls or other internal components.
Refrigerant should not simply disappear through normal operation. If levels are low, there may be a leak that needs to be located and repaired by a licensed technician.
This is not a DIY job.
When It Is Time to Call a Technician
Book a professional inspection if the system:
Keeps blowing warm air
Ices up repeatedly
Has very weak airflow
Leaks water
Shows an error code
Makes unusual noises
Trips the power
At Allfield RACS, our technicians check the areas that can affect cooling performance, including airflow, coils, refrigerant, controls and electrical components.
The goal is to identify the actual cause rather than guess at the problem.
Air Conditioner Not Cooling in Perth?
At Allfield Residential Air Conditioning Services, we service and repair reverse-cycle ducted and wall-mounted split systems across the Perth metro area.
If your air conditioner is still blowing warm air after the basic checks, our technicians can diagnose the fault and recommend the right next step.
Need your air conditioner checked?
Contact Allfield RACS to book a professional service or repair.