A split AC removes litres of water from the air every day in Jeddah's humidity. That water collects in the indoor drain pan and leaves through a small pipe. When it ends up on your floor, wall or ceiling instead, one of five things has happened.
1. Blocked condensate drain
Dust, algae and biofilm build up inside the drain line. Water backs up in the pan, overflows the lip and runs down the wall. The fix is a flush and a check of the trap and the drain outlet, plus a look at whether the outlet is sitting in standing water. In humid, dusty conditions this returns every 6–12 months unless the line is cleaned during the annual wash.
2. Frozen evaporator coil
If airflow is low or refrigerant is low, the indoor coil drops below freezing and frosts over. The unit stops cooling, then the ice melts all at once and the pan cannot keep up. Water appears in bursts, often after a long run. You will usually notice weak airflow first. This is why a leak complaint sometimes ends with a cooling diagnosis rather than a drain repair.
3. Wrong or shifted slope
The indoor unit must sit level or with a slight fall towards the drain side. A unit installed with a counter-slope, or one that has shifted on tired brackets, holds a shallow pool that eventually spills from the wrong edge. We check with a level, re-hang if needed and confirm the water leaves the pan.
4. Cracked drain pan or perished insulation
Older units develop hairline cracks in the plastic pan, and the copper lines' insulation crumbles in the heat, so condensation forms on bare pipe and drips. Pan replacement, fresh insulation and pipe re-lagging solve both.
5. Leaking flare joint
Occasionally the "water" is refrigerant oil mixed with condensate at a flare nut. That joint needs re-flaring and a pressure test, not a mop. We check for oil staining around the connections.
How the visit runs
- Trace the water path - indoor unit, wall, ceiling or outdoor side.
- Open the indoor unit, inspect the pan, coil and drain connection.
- Flush the drain and test-flow several litres through it.
- Check airflow, coil condition and refrigerant pressures if icing is present.
- Re-level the unit or replace the pan or insulation as required, then run the AC for 20–30 minutes and confirm it is dry.
Preventing it coming back
Book the drain flush together with the annual AC washing. A unit that is washed and drained once a year rarely leaks, and the wash also protects the coil from the dust that causes icing in the first place.
Ducted and ceiling units need a different check
With a ducted or ceiling cassette system the drain pan is above your ceiling, so the first sign is usually a stain, not a drip. By the time water shows through plasterboard the pan has been overflowing for a while, and the insulation around it is often soaked. We check the pan, the secondary drain and the float switch where one is fitted, and we tell you honestly when the ceiling needs to dry before the unit is run again.
For cassette units, a sagging or misaligned pan gasket is a common cause that a standard drain flush will not fix.
A five-minute check you can do yourself
- Look at the indoor unit while it runs - is water beading on the coil face or dripping from the casing seam?
- Check the outdoor drain outlet - is anything coming out? A dry outlet during humid weather suggests a blockage.
- Feel the airflow - weak airflow plus water usually means icing, not a drain problem.
- Look for oil staining around the copper connections, which points to a refrigerant leak rather than condensate.
None of this replaces a proper check, but it tells you which service to book - a drain flush, a cooling diagnosis, or a leak test.