Common Air Conditioning Problems and How to Identify Them
An air conditioner usually shows warning signs before it fails. Here are the most common problems and how to recognise them.
When an air conditioner stops working as expected, the cause is not always obvious. Some problems have simple explanations, while others need a professional to diagnose.
This guide covers four areas: an air conditioner that is not cooling properly, weak airflow, unusual noises, smells or leaks, and some safe checks you can make before you call for help.
Air Conditioner Not Cooling Properly
If your air conditioner is running but not cooling as it should, start by checking the mode and temperature settings. Dirty filters, blocked vents, or debris around the outdoor unit can also restrict airflow and reduce cooling performance. If these checks do not help, the problem may involve the fan, controls, refrigerant system, or the unit’s capacity for the space.
Pay attention to when the problem occurs. If the system struggles only on very hot days, heat entering the room or an undersized unit may be contributing factors. If it consistently takes too long to cool, there may be an airflow issue or a developing fault. Sharing these details with a technician can help them identify the cause.
Weak Airflow From the Vents
Weak airflow is often caused by dirty filters or obstructions around the indoor unit and air vents. Clean or replace the filters according to the manufacturer’s recommendations, and move furniture or curtains away from the vents.
For ducted systems, weak airflow in certain rooms may indicate an issue with the ductwork or zone settings. Check the outdoor unit for leaves and debris that could restrict airflow, switching the system off before clearing the surrounding area. If airflow does not improve after these basic checks, a technician may need to inspect the fan or other components.
Unusual Noises, Smells or Water Leaks
While some humming and clicking sounds are normal, new noises such as rattling, grinding, banging, or squealing may indicate a problem. Unusual smells should also be checked, particularly musty odours that may point to moisture build-up. If you notice a burning smell, switch the unit off and arrange a professional inspection before using it again.
Water leaking around the indoor unit may be caused by a blocked drain line, a damaged drain pan, or another fault. Although some cracking sounds can occur as materials expand and contract, persistent or worsening noises should not be ignored. If you notice unusual sounds, smells, or leaks, have the system checked before the problem gets worse.
Safe Checks to Try Before You Call
Before contacting a technician, check that your air conditioner is set to the correct mode and temperature, and make sure the remote control has working batteries. Inspect the filters and clean or replace them as recommended, then ensure the vents and areas around both units are clear.
If the system will not turn on, check whether the circuit breaker has tripped. If it trips again after being reset, stop using the system and contact a qualified technician. Avoid opening electrical panels or handling refrigerant yourself, as these tasks require appropriate training and licensing.
Keep a note of any problems you notice, including unusual noises, cooling changes, or the condition of the filters. A short video of an unfamiliar sound can also help your technician understand the issue before arriving.
If a problem persists after these simple checks, or you are unsure what is causing it, contact WCA HVAC&R for professional assistance with your air conditioning system.
