AC Water Leakage from Indoor Unit — Why It Happens and How to Fix It in Delhi
Nothing is more alarming than walking into your room and finding a pool of water directly below your split AC indoor unit. This is one of the most frequently reported AC problems across Delhi and NCR — and while it looks serious, most causes are straightforward repairs when addressed promptly.
Ignoring AC water leakage, however, is not an option. The water dripping onto your walls, furniture, and flooring causes paint damage, mold growth, and in homes with wooden flooring, warping that costs far more to repair than the original AC fault.
This complete guide explains every single reason your AC indoor unit leaks water, which checks you can do yourself, what each repair costs in Delhi, and how to prevent the problem from recurring.
How Your AC Produces Water — The Basic Explanation
Your AC does not use water to cool — but it produces water as a byproduct of the cooling process. When warm, humid Delhi air passes over the cold evaporator coils inside the indoor unit, moisture in the air condenses into water droplets — exactly like condensation on a cold glass in summer.
This condensed water collects in a drain pan directly below the evaporator coils and flows out through a drain pipe that exits the wall behind your indoor unit. Under normal operation, this water drains silently and you never notice it. When anything disrupts this drain path, water overflows the drain pan and drips into your room.
7 Reasons Your AC Indoor Unit Is Leaking Water in Delhi
Reason 1 — Blocked or Clogged Drain Pipe
This is by far the most common cause of AC water leakage in Delhi — accounting for over 60 percent of all indoor unit drip complaints. The drain pipe that carries condensate out of your home gradually accumulates algae, mold, dust, and debris. Delhi's dust-heavy air accelerates this accumulation significantly.
When the pipe blocks partially, drainage slows and the pan fills up. When it blocks completely, the pan overflows immediately.
Signs: Water dripping steadily from the indoor unit even when AC is running normally. Dripping increases during humid monsoon months when condensation volume is highest.
Fix: Drain pipe cleaning — the technician uses compressed air or a wet-dry vacuum to clear the blockage and flushes the line with a cleaning solution to prevent rapid re-clogging.
Cost: Rs 200 to Rs 500.
Prevention: Request drain pipe cleaning as part of every annual AC service.
Reason 2 — Dirty Evaporator Coils Causing Ice Formation
When the evaporator coils are coated with dust — extremely common in Delhi after months of use — airflow across the coils is reduced. The coils get colder than normal because air is not absorbing the cold efficiently. The coils freeze over, forming a solid ice layer.
When the AC is switched off, or when the compressor cycles off, this ice melts rapidly — producing far more water than the drain pan and pipe can handle. The result is a sudden, heavy drip or pour of water from the indoor unit.
Signs: AC drips heavily a few minutes after being switched off. Ice visible on copper pipes or through the indoor unit grille. AC cooling was poor before the dripping started.
Fix: Evaporator coil deep cleaning using foam solution and flush. Drain line also cleaned to handle the increased water volume during recovery.
Cost: Rs 399 to Rs 799 as part of a deep cleaning service.
Reason 3 — Low Refrigerant Gas Causing Coil Freezing
Low refrigerant causes the evaporator coils to run at an abnormally low pressure and temperature — far colder than designed. Moisture in the air freezes solid on the coils regardless of airflow. This scenario produces more ice than dirty coils and causes more dramatic leakage when it melts.
Signs: AC was running poorly — not cooling well — before the leaking started. Ice visible on the copper pipes outside the indoor unit. This is a more serious situation than dirty coils alone.
Fix: Gas pressure check, leak detection if applicable, gas refill to correct pressure.
Cost: Rs 800 to Rs 2,500.
Reason 4 — Incorrect Installation Angle of Indoor Unit
The indoor unit must be installed with a very slight backward tilt — so that condensate flows toward the drain pan and into the drain pipe. If the unit was installed level or with a forward tilt, water flows toward the front of the drain pan and drips out of the bottom of the unit instead of draining away.
This is an installation fault, not an operational failure. It is particularly common in Delhi where many ACs are installed quickly by untrained technicians.
Signs: AC drips water from day one or shortly after installation. No blockage found in drain pipe. Water comes from the front edge of the indoor unit.
Fix: Reinstallation of the indoor unit with correct tilt angle. All mounting screws and wall brackets need to be repositioned.
Cost: Rs 400 to Rs 900.
Reason 5 — Cracked or Disconnected Drain Pan
The drain pan itself can crack due to physical impact during installation or maintenance, or can degrade from prolonged water exposure and heat cycling. A crack in the drain pan means water bypasses the drain pipe entirely and falls through the indoor unit body.
Signs: Water drips from an unexpected location on the indoor unit, not just the front edge. Drain pipe is clear and unblocked but leaking continues.
Fix: Drain pan repair with sealant for minor cracks, or drain pan replacement for significant damage.
Cost: Rs 400 to Rs 1,200.
Reason 6 — Disconnected Drain Pipe
During servicing or installation, the drain pipe connection at the indoor unit can work loose, particularly if flexible PVC pipe has been used and has stiffened with age. A partially disconnected pipe allows water to leak at the joint inside the wall cavity or directly behind the indoor unit.
Signs: Wall behind or below indoor unit becomes damp. Drain pipe outlet outside the building has reduced or no water flow during operation.
Fix: Reconnecting and securing the drain pipe with appropriate fittings and sealant.
Cost: Rs 200 to Rs 500.
Reason 7 — Humidity Overload During Delhi Monsoon
During July and August, Delhi's outdoor humidity can reach 85 to 95 percent. The volume of condensate your AC produces increases dramatically because the air entering the indoor unit carries much more moisture. A drain pipe that handles normal load adequately may be overwhelmed during peak monsoon.
This is not a fault per se — but regular drain cleaning before monsoon season prevents it from becoming a problem.
Fix: Pre-monsoon drain pipe cleaning and capacity check.
Cost: Rs 200 to Rs 500.
AC Water Leakage Repair Cost in Delhi 2025
| Problem | Repair Cost |
|---|---|
| Drain pipe cleaning and unblocking | Rs 200 to Rs 500 |
| Evaporator coil cleaning — deep service | Rs 399 to Rs 799 |
| Refrigerant gas refill | Rs 800 to Rs 2,500 |
| Installation angle correction | Rs 400 to Rs 900 |
| Drain pan repair or replacement | Rs 400 to Rs 1,200 |
| Drain pipe reconnection | Rs 200 to Rs 500 |
| Full diagnosis and repair | Rs 500 to Rs 2,000 |
What Damage Does Ignored AC Water Leakage Cause?
Many Delhi homeowners ignore a dripping AC because it seems minor — they place a towel below and carry on. This is a costly mistake over time.
Wall paint and plaster damage — continuous moisture causes paint to peel, plaster to soften and crack, and eventually the wall surface needs replastering and repainting. Cost: Rs 2,000 to Rs 8,000 depending on area.
Mold and fungal growth — persistent moisture on walls and ceiling creates mold patches within days. In Delhi's warm climate, mold spreads rapidly. Remediation costs Rs 1,500 to Rs 5,000 and the underlying moisture problem must be fixed first.
Electrical hazard — if the dripping reaches electrical wiring in the wall or ceiling, it creates a short circuit and shock risk. This is particularly dangerous in older Delhi buildings where wiring may run close to the AC installation point.
Wooden flooring and furniture damage — water pooling on wooden flooring causes swelling and warping within days in Delhi's heat. Furniture legs and bases are also affected.
How to Temporarily Stop AC Dripping While Waiting for a Technician
If water is dripping and you cannot get a technician immediately, here is what you can do safely:
Switch the AC to fan-only mode — this stops the cooling cycle and prevents further condensate production while still circulating air.
Clear the drain pipe exit outside — sometimes the drain pipe exit point outside the building gets blocked by debris, bird nests, or overgrowth. Check and clear the outside end of the pipe.
Do not poke wires or tools into the indoor unit — this risks damaging the coils and creating a more expensive repair.
How RepairWalaa Fixes AC Water Leakage in Delhi
RepairWalaa AC technicians bring drain cleaning equipment, foam coil cleaners, gas pressure gauges, and tilt measurement tools on every visit — ensuring the actual cause of the leak is identified and fixed rather than just the drain pipe being cleaned as a blanket solution.
All repairs include a post-service run test to confirm drainage is working before the technician leaves. Same day service available across all Delhi NCR areas with 30-day service warranty.