What you'll notice
The indoor unit powers on, the fan runs and the remote responds, but the air coming out is room temperature or barely cool. The outdoor unit may be silent, or running without the fan turning.
Why it happens
Most often this is a loss of refrigerant charge from a leak in the pipework or at a flare joint, a failed run capacitor leaving the compressor unable to start, or a contactor that is not closing. Genuine compressor seizure is the least common of these, though it is the one people assume first.
This is the fault that generates more aircon call-outs than any other, and it is also the one most often misdiagnosed. An aircon that runs without cooling is telling you that air is still moving but heat is no longer being carried away — and there are several very different reasons for that, at very different price points.
The cheap causes, checked first
A run capacitor is a small cylindrical component that gives the compressor motor the phase shift it needs to start turning. They fail regularly in South African conditions, they cost a fraction of a compressor, and a unit with a dead capacitor behaves exactly like a unit with a dead compressor from the outside. The contactor — the relay that switches power to the outdoor unit — is similarly cheap and similarly prone to pitted or welded contacts after a few summers.
The refrigerant question
If pressures are low, the system has leaked. Refrigerant is not consumed in normal operation, so a low charge always means a leak somewhere. Topping up without finding it means the same call-out again next season, which is why we pressure-test and trace rather than simply regassing and leaving.
How we fix it
We measure suction and discharge pressures to see whether refrigerant is present and circulating, test the capacitors under load, and check whether the contactor is actually pulling in. That sequence separates a part worth a few hundred rand from a compressor failure before anyone quotes for the expensive option.
Still not working?
If the checks above haven't restored your compressor, this usually needs a technician. Our Aircon Repairs service covers exactly this fault — from R650, quoted upfront.