First check that the AC is switched on at the point, the MCB is on, the remote is set correctly and the filter is clean. Book a technician if the room still does not cool, if water drips from the indoor unit, if the unit trips the MCB, makes a new noise or smells of burning. Switch off a unit that smells of burning and do not open it.
Check these first
Take two minutes before you book anyone. These are the checks that most manufacturers' guides suggest first.
- Is the AC switched on at its power point and is the MCB on?
- Does the remote have batteries, and is it set to cool with a sensible temperature?
- Are doors and windows closed in the room?
- Is the filter dusty? Many filters can be taken out, rinsed and dried. Follow your manual.
- Is the outdoor unit blocked by boxes, a wall or hanging clothes?
If these do not help, move to the list below. Do not open the casing or touch any wiring.
The AC runs but the room does not cool
Causes range from a choked filter and a blocked outdoor unit to a problem inside the cooling system. A room that is much larger than the AC suits, or one that gets strong afternoon sun, can also feel as if the AC has failed.
If the filter is clean and the airflow looks good, a technician needs to find the cause. Some causes need special tools. When you book, ask what the technician will check and whether they handle that kind of fault. We do not describe every possible AC repair on this website, so confirm the job with us before you rely on it.
Water leaking from the indoor unit
An AC removes moisture from the air, and that water leaves through a drain pipe. Chennai's humid air means a lot of it. If water drips from the indoor unit into the room, the drain may be blocked or sloping the wrong way, or the unit may have been installed slightly out of level.
Put a bucket under it and switch the AC off if the dripping is heavy or near sockets. A technician can check the drain and the unit.
The AC trips the MCB or will not start
This one deserves care, because it could be the appliance or the electrical supply. A fault in the AC, a loose connection at the power point or an overloaded circuit can all trip the MCB.
- Do not keep resetting the MCB.
- Do not plug the AC into another extension board to see if it works.
- Tell the technician it trips and when, for example "as soon as the compressor starts".
Because our team handles the electrical side as well, the AC repair and service page also covers power supply, wiring and MCB problems that affect the AC.
Noise, vibration and smells
A new rattle, hum or buzz may be a loose panel, a fan problem or something touching the casing. A musty smell often comes from damp inside the unit in humid weather. A burning smell is different. Switch the AC off at the power point, and at the MCB only if it is safe to reach, then call. Do not run it again until it has been checked.
Chennai conditions that affect your AC
- Long hot season. An AC that runs for many hours every day wears faster, so small faults grow.
- Humidity. More moisture means more drain water and a greater chance of musty smells.
- Coastal air. Salty air can corrode outdoor units and fittings, especially near the sea. Look at the outdoor unit once in a while for rust.
- Dust and traffic. Near busy roads, dust can clog filters faster, so check them more often.
Repair or replace?
An AC that is many years old and keeps developing faults raises this question. The answer depends on the unit's age, what has gone wrong and what the repair involves. Ask the technician to explain the fault and the options plainly, and to say what they would do if it were their own AC. If you do replace it, the old unit has to come down first. See our guides to AC uninstallation and installing a new AC.
What to tell the technician
You will get a faster visit if you can say: the make and approximate age of the AC, when the problem started, what you see or hear, whether the MCB trips and whether the unit is on a dedicated point. A short video of the noise or the leak can help.
When you are ready to book, see our AC repair and service page, call us or message us on WhatsApp. We do not state prices or response times on this website, so ask when you contact us.
Key takeaways
- Check power, settings and the filter before booking.
- Water dripping inside, a tripping MCB and burning smells need a professional.
- Humid, coastal air makes an AC work harder and can corrode the outdoor unit.
- An AC that trips the MCB may have an appliance fault or an electrical fault. Both need looking at.
- Tell the technician what you saw and when, not only that it is not cooling.
