Overview
An AC leaking water inside the room, whether you call it an air conditioner or an aircon, nearly always has one of nine causes, and the commonest by far is a blocked drain line. An air conditioner makes water every hour it runs, and that water should leave through a drain pipe. When it drips from the unit, the wall or the ceiling, something has stopped it getting there.
This guide tells you what to do first, how to work out the cause from where and when the water appears, which fixes are safe to do yourself, and what a repair costs in Dubai. It covers split, ducted and central AC, cassette, window and portable units, in a house, a flat or an office.
AC leaking water: the short answer
If your AC is dripping water indoors, or water is leaking from the split AC indoor unit, work down this list and stop when you find the cause. Each step is explained further down the page.
Water near electrics is the first risk. Use the remote, then the wall isolator.
Move furniture and electronics, and put a towel and a bucket under the drip.
If they are grey with dust, wash them. A blocked filter freezes the coil, and the ice melts into the room.
Open the front panel. Ice on the coil means airflow or gas, not the drain.
Find where the drain pipe ends, outside or at a floor drain. No drip there while the AC runs on a humid day means the drain is blocked.
From the casing, down the wall, from the ceiling or from a vent. The table below matches each place to a cause.
Clearing a drain properly, and anything involving ice that returns, a pump or a ceiling unit, needs tools and access.
The only lasting AC water leakage solution is to fix the cause. Wiping up and restarting brings the water back within hours.
What to do in the first ten minutes
In the first ten minutes, make the area safe, limit the damage and collect the clues a technician will need. A leak that is still running hides its own source, so the aim is a dry unit and a clear record of where the water came from.
Switch off at the remote and at the isolator. If water has reached a socket, a light fitting or the distribution board, switch off that circuit at the board and keep clear.
Electronics, rugs, mattresses and wooden furniture first. Lift curtains clear of the wall.
A bucket under a ceiling leak, a folded towel on a shelf below a wall unit.
One of the wet area showing where the water starts, and one of the unit's nameplate.
Did it drip while running, or only after the unit was switched off? Did it start after a service, a move, or a spell of humid weather?
With cooling off, the fan melts ice in twenty to thirty minutes. Keep the bucket in place while it does.
For water coming through a ceiling or reaching electrics, call us. We send a technician the same hour for emergencies.
Is water from an AC normal?
Water from an AC is normal when it comes out of the drain pipe, and a fault when it comes out anywhere else. An air conditioner cools the air below its dew point, so moisture condenses on the cold coil, runs into a tray and flows away down the drain. In Dubai's humid months a single unit produces several litres a day.
People ask why water is coming from the AC at all. The answer is that it always does. Condensation from an AC only becomes a leak when its way out is blocked, broken or bypassed.
Find the cause by where the water is
Where the water appears, and when, narrows nine causes to one or two. Use this table before reading the causes in detail.
These are the causes of AC leaking water in the order we meet them. If you can see ice, start with cause 2. If there is no ice and the unit drips while running, start with cause 1.
Cause 1: a clogged drain line
A clogged drain line is the reason behind most AC water leakage. The pipe is narrow, always wet and fed with dust from the coil, so slime and algae grow in it until water can no longer pass. The drain pan then fills and overflows into the room.
How to recognise it
Why it happens in Dubai
What you can do
Find the end of the drain pipe, if it is reachable outdoors or at a floor drain. A wet-and-dry vacuum held over the end for a minute is the safe way to unclog it, and often pulls the blockage out. Do not push wire up the pipe from inside the unit: it can puncture the pan or pull the hose off its spigot inside the wall.
What a technician does
The line is cleared by suction or pressure from the outlet end and flushed until water runs freely. The pan is cleaned, and a measured amount of water is poured in to prove it drains. If the blockage is in the building's shared drain, the building management has to clear that section.
Having the AC drain cleaned at each service prevents this cause almost entirely. See AC cleaning.
Cause 2: a dirty filter and a frozen coil
A blocked filter starves the evaporator coil of warm room air, the coil drops below freezing, and the moisture on it turns to ice. When the unit stops, or the ice grows heavy, it melts faster than the pan can carry away and falls outside the pan. The sign is water that appears after switching off.
How to recognise it
What to do
Let the ice melt fully, with a towel below.
Rinse from the clean side, dry in the shade and refit.
Curtains, furniture or a closed louvre in front of the unit.
If airflow is strong and no ice returns within a day, it was the filter.
If the filters were clean, or ice returns, the coil itself is clogged or the gas is low. A clogged coil needs a deep clean. If cooling has dropped as well, see our guide to an AC not cooling.
Cause 3: low gas
Low refrigerant gas makes the coil colder than it should be, so it ices even with clean filters. The ice melts and drips in the same way as in cause 2. Low gas always means a leak in the pipework, and adding gas without repairing it brings the ice back.
This needs gauges and a leak test. Our AC gas refill page explains how the leak is found and repaired.
Cause 4: a cracked, rusted or overflowing drain pan
The drain pan, also called the drain tray or drip pan, sits under the coil and collects the condensate. It overflows when its outlet is blocked, and it leaks when it cracks or rusts through. On a wall split the pan is plastic and part of the casing. On ducted and older units it is metal.
A blocked pan is cleaned. A cracked plastic pan or a rusted metal one is replaced, because sealant on a wet, flexing pan rarely lasts a summer. We replace drain pans, and quote the part once the model is known.
Cause 5: the indoor unit is not level, or the drain pipe has no fall
A wall unit must sit level, or tilt very slightly towards its drain side, and the drain pipe must run downhill all the way. If the unit leans the other way, water collects at the wrong end of the pan and spills. If the pipe rises or sags anywhere, water stands in it and backs up.
The fix is to re-hang the unit level and re-route the drain so it falls continuously. Where the pipe cannot fall, because the outlet is higher than the unit, a condensate pump is fitted. Our AC installation page describes how a drain should be laid.
Cause 6: the condensate pump has failed
Cassette units, many concealed ducted units, and any unit whose drain must run uphill rely on a small condensate pump to lift the water. When the pump fails or its float switch sticks, the pan fills and overflows, usually onto a ceiling.
A pump clogged with slime can be cleaned. A pump with a failed motor is replaced. If your AC condensate pump is not working and the unit keeps running, switch the AC off, because the pan will overflow.
Cause 7: pipe insulation missing or split
The cold copper pipes and the drain pipe are wrapped in foam insulation. Where that insulation is missing, split or soaked, the humid air of a ceiling void or wall cavity condenses on the cold surface and drips. The leak follows the pipe route and not the unit.
The repair is new insulation of the right thickness, with each pipe wrapped separately and every joint taped. We re-insulate pipes, and where they run above a ceiling, access is the main part of the job.
Cause 8: humid air getting in
When very humid outside air reaches the unit, it makes more condensate than the pan and drain were sized for, and water forms on the casing and louvres as well. In Dubai this shows in August and September, when a balcony door or window is left open with the AC running.
What helps
If the unit still drips with the room closed up, the drain is partly blocked and can no longer keep up.
Cause 9: a dirty coil or fan throwing water
On a coil coated with dust and slime, water cannot run down the fins into the pan. It bridges across them, is picked up by the airflow and is thrown into the room as drops or a fine spray. A dirty fan barrel does the same with water that reaches its blades.
A deep clean of the coil, fan barrel and pan cures it. Lowering the fan speed reduces the spitting until then.
Water dripping from a ceiling vent or through the ceiling
Water from a ceiling vent or a ceiling stain comes from a central AC unit, an air handler or a duct hidden above. These leaks matter most, because they damage the ceiling, light fittings and sometimes the flat below. Switch the AC off as soon as you see one.
A fan coil unit leaking water is serviced in the same way as a ducted split, through the ceiling hatch. Sweating ducts are covered on our AC duct cleaning page.
Do not poke a bulging ceiling. A gypsum ceiling holding water can come down in pieces.
Window and portable AC leaking water
A window AC leaking water inside is nearly always tilted the wrong way. It should lean slightly outwards, so that condensate runs to the back and drips outside. A portable AC collects water in a tank, or sends it down a hose, and leaks when the tank is full or the hose is kinked.
A window unit that has not been taken out and washed for years holds a layer of mud in its base. Cleaning it restores the drainage.
Water at the outdoor unit
An AC leaking water outside is usually not leaking at all. The drain pipe ends outdoors on most split units, and a steady drip from it is the system working. A little water under the outdoor unit itself is also normal on humid days.
What you can fix yourself, and what needs a technician
You can safely wash filters, melt ice, close up the room, adjust the settings and vacuum the outdoor end of the drain pipe. Anything that means opening the unit, working above a ceiling, handling gas or electrics, or re-hanging the unit needs a technician.
What not to try
AC leaking water repair cost in Dubai
AC leaking water repair in Dubai usually costs between AED 100 and AED 350, because most leaks are a blocked drain cured by cleaning. Our diagnostic visit is AED 100 plus VAT. The figures below are 2026 market prices published by companies in the city, before VAT, and are not our fixed price list.
The technician tells you the cause and the price before starting. Ceiling repairs and repainting are separate building work and are not part of an AC repair.
Is a leaking AC dangerous, and can you keep using it?
A leaking AC is not dangerous in itself, but the water is. It can reach the unit's control board, a socket or a light fitting, it ruins gypsum ceilings and wooden floors, and a wall that stays damp grows mould within days. Do not keep using a unit that is dripping indoors.
In a rented home, tell the landlord or agent the same day and send photos. Water damage that was reported promptly is far easier to settle than damage that was left.
How to stop it happening again
Most AC water leaks are prevented by three habits: clean filters, a drain flushed at every service, and a closed room in humid weather.
Frequently asked questions
Why is my AC leaking water all of a sudden?
A drain that has been narrowing for months finally blocks, often in the first humid weeks of summer when the unit makes the most water. A filter left unwashed until the coil freezes is the next most common reason.
Why does my AC drip only after I turn it off?
Ice has formed on the coil while it ran, and melts when it stops. Wash the filters first. If ice returns, the coil is clogged or the gas is low.
Can I use the AC while it is leaking?
No. Switch it off until the cause is fixed, or the water will reach the wall, the ceiling or the unit's electronics.
My AC was just serviced and now it leaks. Why?
The drain hose or pan was probably not refitted correctly, or loosened dirt has blocked the drain. Call the company that did the service.
Is it the same fault on Samsung, LG, Daikin, Gree, Carrier, Midea, Haier, Hitachi and Mitsubishi units?
Yes. Brand makes little difference. On every split AC the water follows the same path: coil, pan, drain hose, outlet.
Does low gas really cause a water leak?
Yes, indirectly. Low gas ices the coil, and the melting ice overflows the pan.
How much water should an AC produce?
It depends on humidity. In Dubai's humid months a unit running all day can produce several litres, all of which should leave by the drain pipe.
Who pays for the leak in a rented flat?
It depends on the tenancy contract and the cause. A blocked drain from missed servicing is often treated as the tenant's upkeep, and a failed part as the landlord's repair.
Book a repair for a leaking AC
If the checks above have not stopped the water, book AC repair through the online form, by WhatsApp or on +971 55 209 9785. Tell us where the water appears, whether there is ice, and the type of unit.
Leave the AC switched off until the technician arrives.
A technician can find the cause on site. The diagnostic is AED 100 plus VAT, and repairs carry a 1-month warranty.