Fault-finding
Water dripping from the indoor unit
Nearly always the drain: blocked with the algae and dust that build up over a season, or run without enough fall so it backs up. Both are cheap. The other cause is a frozen indoor coil melting all at once, which points back to airflow or a low charge rather than the drain itself.
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Clear the drain before anything else
The indoor coil condenses water continuously and it leaves through a drain line. Over a season that line grows a slime of algae and dust that eventually blocks it, the tray overflows, and the water finds the room. Flushing it through is a routine part of a service and it resolves most of these calls.
Check the fall on the drain line
A drain relies on gravity. If the line was run flat, or worse rises somewhere along its length, water pools and backs up as soon as anything narrows it. This is an installation fault rather than a maintenance one, and re-running the line with a proper fall is the only real fix — clearing it will buy weeks, not seasons.
Rule out a frozen coil
If ice formed on the coil and then melted, the volume arrives faster than the tray can drain and spills regardless of the line's condition. Water appearing suddenly in quantity, especially after the unit ran hard, points here. The underlying cause is restricted airflow or a low charge, so fixing the drain alone would leave it unsolved.
The less common ones
A cracked or displaced drain tray, an indoor unit mounted slightly off level so water runs to the wrong end, or insulation missing from the pipework so the pipe itself sweats and drips. All three are installation issues, and all three are worth checking before anyone suggests the unit needs replacing.
Why is my AC leaking water into the room?
Can I clear the drain myself?
Often yes — the outlet end is usually accessible and a gentle flush clears a partial blockage. What to avoid is forcing anything rigid up the line, which can dislodge the pipe inside the wall. If flushing does not fix it, or it returns within weeks, the line's fall is the likely problem and that needs re-running.
Is a leaking AC dangerous?
Not to you, but water running down a wall damages plaster and paint, and if it reaches a socket or a switch it becomes an electrical problem. Switch the unit off and put something under it until it is fixed. It is a cheap repair that gets expensive only when it is left.
Why does it only leak on very humid days?
Because the coil condenses far more water when the air is humid, so a partially blocked drain that copes on a dry day is overwhelmed on a monsoon one. This is the classic pattern of a line that is narrowing rather than fully blocked, and it will get worse. Clear it before the humidity peaks rather than during it.
Rather have it done?
A service is a deep clean of both coils, the filters and the drain, plus a set of measurements that show whether the unit is actually healthy. Servicing starts at PKR 3,000, and gas refilling starts at PKR 6,000 — but a unit needing gas has a leak, and refilling without finding it is a yearly bill, not a repair.
AC servicing and gas refilling in Islamabad — prices and scope