Water Dripping From AC Vent: 9 Causes & Fixes

Imagine this, you prepare to retire to bed after a long tedious day of work and turn on the AC anticipating a burst of cool refreshing air. Instead of that, all your expectations are doused by the sight of water dripping from the AC vent. Hardly a pleasure-inducing thought don’t you think?

No matter when you discover this unpleasant occurrence of your AC, it is bound to make you mad and feel, even if a little bit, stressed. After all, we do not associate water with electronic devices and especially large electronic devices such as Air conditioner which usually consume a good amount of money for repairs.

Although the thought of water being where it does not belong (case in point – the AC vent) is nothing short of stressful for homeowners, there must be some consolation in knowing that this is a rather common thing to happen to AC units from time to time.

But the fact that an air conditioner vent leaking water happens to many households is no excuse to just sit and watch. It must be remedied. But before that, we should be asking, why does this bizarre thing take place? After all, how does the water of all things accumulate in a machine run on electricity? Well, let us find out why.

Water Dripping From AC Vent

9 Causes Of Water Dripping From AC Vent And How To Fix It

Before we discuss how to fix this issue, the first thing that you should do if you see the AC vent leaking water is to turn the machine off so that there is no risk of electrocution. Because after all, safety first!

Dirty Air Filters

Even though it is mentioned that an electronic device should have nothing to do with water, that is hardly the case with an Air Conditioner. The device runs by collecting moisture from the air from inside the room. This moisture is collected into a drip pan and then drained out from the condenser lines situated in the outdoor unit.

This is of course the ideal way of operation except that air is often dirty and contains dust which gathers on the air filters in successive layers forming a thick barrier of sorts through which the air cannot pass.

If the air is blocked before the filters then it means that it will freeze over the evaporator coils and form a layer of ice. More layers will be added to this frozen layer for as long as the filters are dirty and blocking the air. Eventually, when the surface of the evaporator coil gets too congested to even hold any more ice, it will start melting and find an exit through the vent.

Solution: The only way to avoid this situation is to clean the air filters regularly. How often you are to clean it depends on how often you use the air conditioner itself.

On average, you should clean the filters every five days. To do it you will have to lift the front cover of the indoor unit of the AC and locate the sliding panels on which the air filters are slid into.

Usually, there are two filters and they look like an ice tray without the cavities for ice and fine mesh in that place instead. The mesh acts as the filter blocking the dust and debris but letting air pass through it.

You can wash the filter under water but make sure to let it dry completely before putting it back. Or you can take a small brush and start dusting off the accumulated debris from the air filter manually.

A clogged Condensate drain channel

The moisture from the air can accumulate in the air vent in a condensed form causing water dripping from the air conditioning vent. This happens when the condensate drain channel or condensate drain line as it is generally referred to, is clogged.

A clogged condensate drain line can result from a number of problems but the most commonly seen reason is when the Air conditioner is installed in the upper levels of the house, in the attic, or in an upper-level room. The condensate drain line is darwin outside the house and over time it can get filled with dust, debris, algae, mildew, or even tiny critters like bugs and rodents.

Solution: Well yes, you guessed it right, you have to unclog the clogged drain line in order to remedy the situation. The simplest way to do it is to remove the plastic cup manually and assess the amount of debris you are dealing with.

If there are solid components then carefully extract them from the pipe using a clamp or hook. Then pour a cup of distilled water and vinegar inside the pipe and wait for half an hour before you turn the AC back on. Oh and yes, during the cleaning process the device should be disconnected from the electricity socket.

This method will be effective if the drain line is maintained properly and if it has been years since the last maintenance then it is best left to professionals. However, what you can do is perform a proper diagnosis of the situation so that calling the professionals won’t be a waste.

Go check out your condenser unit and see if the drip pan is overflowing. If it is then what you have in hand is definitely a clogged condensate drain line.

Another telltale sign of this situation is a rusting furnace top. A word of caution- a rusting furnace is a potentially dangerous situation and you should get it looked at immediately.

Frozen Evaporator Coils

If cleaning out the dirty air filters has not helped and you still see the AC vent dripping water in small amounts then it is very possible that the culprit behind this is the accumulated ice on the evaporator coils, which is there in the first place because the dirty air filters were blocking the way of the air. Well, there is no need to fret as it can be easily dealt with.

Solution: Warmth melts ice and we all know that. This fact can be employed to rid the evaporator coils of the intruding ice. But you cannot throw hot water on the coil to achieve that end. Instead what you can do is supply warm air to the coil and the ice will melt faster at once.

Since the coil is located just near the AC vent, hold a hair dryer or blow dryer whatever you call it, near the vent. Hold it for a minute or so at the lowest setting, you will see water dripping from the vent. This will help the ice to melt away faster.

Rusted Drip Pan

The drip pan is a designated part of your AC unit that catches the dripping moisture  and ensures that no excess moisture is allowed inside the room where the unit is fit.

If however the drip pan starts to rust and develops a leak then the water will not be stopped and it will manifest unguarded and through the vents.

Solution: The easiest way to deal with a rusted drip pan without having to replace it is to coat with a preventive seal such as PANSEAL. This will repair the drip pan and also cover up the leakages that have been causing water to drip from the vents.

Leak in the Refrigerant

If you don’t know what a refrigerant is then it is the gas that cools the air collected by the AC. This gas is not used as a fuel and is rather stored inside the copper evaporator coil and when the air passes through it, it cools down and then is distributed inside the home with the blower of the AC unit.

Now, the thing about refrigerant gas is that it is quite toxic and volatile and is thus stored safely inside the coil. It performs its role in a closed loop without ever being released until the AC needs replacement after it has had its run.

But sometimes, due to some damage to the coil. It may crack or damage and cause the gas to start leaking. This will eventually lead to frozen evaporator coils and subsequent dripping of water from the AC vent.

One way to tell if the refrigerant is leaking is to note if the air coming out of the AC is warm or not. Lack of enough refrigerant gas will lead to the air not being cooled enough and thus warm air will be emitted. 

Solution: Unfortunately, fixing a leaking refrigerant copper coil is not a DIY task and needs professional expertise owing to two specific reasons.

First- the evaporator coil may have to be replaced and that will need special tools. Second- refrigerant gas is very toxic and harmful if inhaled so it is best not to go near it.

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Air Leaking around the Vent

Something as simple as an air leak around the vent can cause water leaking from the air conditioner vent.

If the air escapes from the sides of the grate then it is obvious that the moisture from the air can build up and condense into water that manifests from the vent,

Solution: A quick end to this problem can be achieved by identifying the exact location from where the air comes out of the grate. Once you have found the place, simply seal it by caulking the spot.

Insufficient Duct insulation

Not many houses have attics that are well insulated and yet the attic houses ducts and channels for ACs and HVAC units alike.

Now these ducts that run through the uninsulated or poorly insulated attics are easy victims to build up condensation in the system. Then the accumulated condensation shows itself through the AC vent dripping water.

This is why insulated ducts are important and should be a must when installing them.

Solution: You can insulate the ducts on your own but it will take some time to have sufficient knowledge and skill to achieve it. The only other way is to get professional help. It will cost you money but the job will be flawless.

Leak above the Ductwork

Although this is not directly related to the AC vent, it is still a fair possibility. The leak could be there in the roof or the plumbing and it may be causing water to travel through the duct and from your AC vents.

Solution: The only way out of this is to identify the source of the leak and call a professional to fix it.

Problem with the Installation

If there is a problem when the AC is being installed, such the unit being tilted or the drip pan being tilted can result in collected moisture polled to the tired side of the drip pan to overflow and come out through the vents.

If none of the above reasons seem to be the case with your water-leaking AC unit, then it is the one in all probability.

Solution: You have to call in a relevant professional and readjust the elevation of the AC so that both sides of it are of the same level and it is not tilted to one side.

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Final Words

Suddenly discovering that the AC unit is leaking water from the vent can be a shocking thing because Air Conditioners cost a lot firstly, and they are sturdy devices that do not need regular repairs but when they do they may blow a hole in your pocket.

But as you have seen, these are some of the likely causes of the problem and can be easily solved, so there is no need to lose your calm at all!

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