Is Your AC Not Cooling? The 10 Most Common Air Conditioner Faults and Their Solutions

Having your air conditioner fail or not cool sufficiently on a hot summer day is a major disappointment. So what are the most common AC faults and what could cause them? In this guide, you will find 10 common air conditioner faults compiled from the field experience of our expert technicians, and what you need to do.

1. The AC Is Not Cooling or Heating

This is the most frequently encountered complaint. Causes include refrigerant gas (freon) deficiency or leakage, dirty coils, a clogged filter, compressor failure, or incorrect thermostat settings. The first check you can do yourself: clean the filter and verify that the thermostat is set to the correct mode. If the problem persists, always call an expert; refrigerant gas recharging cannot be performed by unlicensed individuals.

2. The AC Is Dripping Water (Water Flowing from the Indoor Unit)

Water seeping from the indoor unit is usually caused by: a clogged drainage (condensate trap) line, the unit not being installed on a slope, or a dirty or frozen evaporator coil. Turn the AC off immediately; running it for too long can cause serious damage to the ceiling and walls. Call a technician.

3. The AC Emits a Bad Odor

A musty or damp smell is usually caused by bacteria and mold growing in a dirty filter or on the indoor unit coil. A burning smell indicates an electrical problem — in that case, switch the AC off immediately and cut the power. Antibacterial treatment and deep cleaning can completely eliminate bad odors.

4. The AC Is Operating Very Noisily

Clicking, buzzing, or humming sounds indicate different problems. Clicking: a loose fan blade or a foreign object entering the indoor unit. Buzzing: vibration in the compressor or loose mounting screws. Loud humming: bearing wear in the motor. These sounds are early warning signs; ignoring them leads to expensive repairs.

5. The AC Switches Off on Its Own Frequently (Short Cycling)

This condition, technically known as 'short cycling', can result from an overheating compressor entering safety mode, a thermostat fault, insufficient refrigerant gas, or the AC being oversized relative to the space it serves. Stop running the unit to prevent compressor damage and call for service.

6. The AC Is Not Working at All, an Error Code Is Shown on the Display

Modern inverter air conditioners report faults via digital error codes. Although each brand has different codes, the most common are: E1 (communication error), E4 (high-pressure protection), E6 (indoor-outdoor unit communication fault). Look up the code in your device's user manual; share it with the authorised service to speed up the process.

7. The Remote Control Is Not Working

The first thing to do is replace the batteries and remove any obstruction in front of the IR sensor. Leaving the AC unpowered for 10 minutes and then restarting it (reset) also frequently helps. If the problem persists, the remote may be faulty; a compatible universal remote can be used instead.

8. The Outdoor Unit Fan Is Not Spinning

When the outdoor unit fan stops, the condenser does not cool sufficiently, causing the compressor to overheat and shut down. A motor fault, a failed capacitor, or a foreign object (leaf, wire, etc.) jamming the fan are the main causes of this fault. The front of the outdoor unit must always be kept clear and free for airflow.

9. The AC Is Icing Up (Evaporator Freezing)

Ice forming on the indoor unit or piping is a serious problem. Low refrigerant pressure, a clogged filter blocking airflow, or a fan fault cause this condition. Run the AC in 'fan only' mode to defrost the ice, then call for service.

10. The Circuit Breaker Is Tripping

If the breaker trips when your AC starts up or while it is running, there may be a risk of electric shock or fire. A short circuit in the compressor, an earthing problem, or inadequate cable cross-section are among the causes. Never attempt to fix this fault yourself; call an expert technician who is proficient in both electrical and refrigeration systems.

Prevention Before Breakdown: Regular Maintenance Is Essential

The vast majority of the faults listed above can either be completely prevented or detected early and resolved at minimal cost through regular periodic maintenance. Having professional maintenance performed twice a year is a much more economical solution than potential breakdown repairs. Contact us now to diagnose your fault or book a maintenance appointment.