Jeddah summers push AC units harder than almost anywhere. A split unit in a west-facing apartment may run 18 hours a day for five months, and the failures that follow are predictable. Here is what we actually find, in rough order of frequency.
1. Restricted airflow - the cheapest fix
Before any gauge goes on the unit, the filters, blower wheel and indoor coil get checked. A clogged filter or a dust-felted evaporator drops the airflow, the coil ices over, and cooling collapses. Jeddah's dust load makes this the single most common cause of "not cooling" between washes. If the coil is matted, a proper chemical wash restores performance without touching the refrigerant circuit.
You can check this yourself: if the indoor unit's airflow feels weak, or you can see a grey mat across the filter, start there.
2. Electrical faults - capacitor and contactor
Heat kills electrolytic capacitors. A swollen dual-run capacitor stops the compressor or the outdoor fan from starting, so the indoor fan runs and the air stays warm. This is a fast, inexpensive repair, and a technician with a multimeter can confirm it in minutes. A pitted contactor or a tripped thermal overload produces the same symptom.
3. Low refrigerant from a leak
If airflow and electrics check out, we move to pressures. Low suction pressure with a warm indoor coil points to a leak. We then pressure-test with nitrogen and find it rather than simply topping up - see AC gas refill in Jeddah for how that visit runs.
4. Dirty or blocked outdoor unit
The condenser has to dump heat into already-hot air. Sand, dust and salt film on the coil fins, a unit boxed in by laundry or a wall, or a fan that is running at the wrong speed all raise the head pressure and cut cooling. We clean the coil, check the fan blade and motor, and confirm the unit has clear air around it.
5. Compressor or PCB failure
If the compressor draws current but does not pump, or the inverter board is not driving it, you are into the expensive end. We measure winding resistance and insulation, test the start components and, on inverter units, read the fault codes. We then give you the honest comparison: repair cost against the cost of a replacement unit, including installation and disposal. Sometimes the answer is "do not spend on this one".
What to have ready before we arrive
- The AC type - split, window, ducted, floor-standing, central.
- Capacity in tons or BTU, printed on the indoor or outdoor unit label.
- What changed: weak cooling from day one, sudden loss overnight, noise, water, tripping the breaker.
- Your district and building access notes (gate code, parking, lift).
A photo of the outdoor unit's rating plate speeds this up more than any explanation.
What the visit costs
Diagnosis is a fixed charge, and any repair is quoted before it starts. If the fault needs a part, you get the part price and the labour price separately. Ranges for common repairs are listed in the AC price guide for Jeddah.
What the first 30 minutes of a visit look like
We do not start by opening the gas ports. The first half hour is measurement, because every reading narrows the cause:
- Supply and return air temperature at the indoor unit - the split tells us whether the coil is transferring heat.
- Filter and evaporator condition, plus blower speed.
- Outdoor unit: fan operation, coil condition, ambient temperature, and whether the compressor is actually running.
- Electrical: supply voltage, capacitor capacitance, contactor condition, compressor current draw.
- Refrigerant: suction and discharge pressure, superheat where accessible.
By the end you should be able to repeat the fault back to us in one sentence. If the explanation is vague, the diagnosis is not finished.
When the problem is the building, not the AC
Some "not cooling" complaints are not the unit at all. Duct runs that leak cold air into a ceiling void, a thermostat mounted where afternoon sun hits it, a room with west glazing and no shading, or a split that was sized for a smaller room will all produce the same complaint. We tell you when the numbers point that way - replacing parts inside a healthy unit does not fix a heat-load problem.
For ducted systems, a duct inspection is worth doing before spending on refrigerant. For rooms, closing curtains and running the fan on high during peak hours is a free test you can repeat.