Every air conditioner removes moisture from the air as it cools. That water collects in a drain pan and runs away through a pipe. When the pipe blocks, the pan overflows, and the water comes out wherever it can find a route, which is usually through your ceiling.
Why drains block so often in Dubai
Three conditions combine here that do not combine elsewhere. Air conditioning runs close to year-round rather than seasonally, so the drain pan is wet almost continuously. Ambient humidity is high for much of the year, so the volume of condensate is large. And the air carries fine desert dust, which settles in the pan.
Permanently wet surfaces plus organic and mineral dust produce biological sludge. That sludge gradually narrows the drain until flow stops. It is not a defect; it is the predictable outcome of the operating environment, which is why drains here need checking on a schedule rather than when they fail.
What a proper fix involves
Clearing the line is the easy part. The important part is cleaning the pan, because the sludge that blocked the line is still sitting there and will reform within weeks otherwise. Any contractor who blows the line through and leaves is selling you a repeat visit.
The full job is: clear the line, remove and clean the drain pan, treat the pan surface, verify the fall on the pipe run, and check the trap where one is fitted. On systems with a condensate pump, the pump and its float switch need checking too, because the same sludge jams floats.
Fall and trap problems
Sometimes the drain was never right. Condensate lines rely on gravity, and a run installed with insufficient fall, or with a dip that holds water, will block repeatedly no matter how often it is cleared. If your drain blocks every few months, the pipework itself is worth inspecting rather than the pan.
The safety switch
Many units have a float switch that cuts the system off when the pan fills, to prevent exactly the ceiling damage described above. If your AC shuts itself down rather than leaking, that switch is working correctly and the underlying blockage still needs clearing.
What to do when it leaks
Switch the unit off and place a container. Running it longer does not clear anything and every hour adds to the ceiling repair, which routinely costs more than the AC work that caused it.
Related: AC leaking water, water dripping from a cassette, coil and drain servicing.
Need this looked at?
inspection, fixed written price before any work begins, and a before/after photo report on every job.