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My air conditioner gets frozen, why?

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If an air conditioner machine gets frozen doesn’t mean we have a “cold cannon” and our machine is working at its finest. On the contrary, this is a sign our machine gives us to let us know something wrong is happening. Houston, we have a problem! If that is your case, keep on reading!

Why does air conditioner gets frozen?

It’s a common breakdown if air conditioner makes ice or even it totally gets frozen, this can happen in both internal and external unit, but it is in the internal unit where we see this breakdown more often, not because it is produced there much more times, but it’s there where it’s easier to see it for being inside house or being more accesible.

A lack of gas is a possible cause an air conditioner gets frozen or frosts.

Let’s see symptoms why an air conditioner gets frozen

Before we realize our air conditioner has a breakdown and, depending on the kind of breakdown, air conditioner gives us some symptoms when something isn’t working properly, as in many other common breakdowns, the freezing problem of air conditioner comes preceded by some symptoms, which are:

  • My air conditioner doesn’t throw enough air: An air flux descent shows us something very clear: there isn’t enough air flux through internal exchanger (internal radiator). The great air conditioner majority impels (throws) the same air they gather from the room where they are installed, so if air conditioner gets frozen this exchanger gets clogged because of an ice layer formation in all its surface, avoiding air flux to pass to the machine and therefore the impelling of air volum expelled.
  • My air conditioner throws ice or water: In general, when air conditioner gets frozen it uses to release pieces of that ice and in many occasions these ice pieces end getting through the external fan (wings) which expells them to exterior at the same time it impels air to the room; in some occasions air conditioner throws ice and in other occasions what we see is water drops from this ice which melts.
  • My air conditioner throws water on the inside: As we mentioned before, if your air conditioner frosts or it reaches to get frozen, it’s very likely this ice to release itself and get impelled by the fan, but another thing that may happen is air conditioner doesn’t throw ice but very cold water.
    Another one of causes an air conditioner throws water and due to freezing, it’s because when the ice layer which appears in the internal unit defrosts, it makes plughole to overflow because of the great amount of water which can’t evacuate correctly.
  • My air conditioner warms a little or it warms during a few minutes and then it doesn’t warm or not that much: As well as it exists the chance the internal unit gets frozen, it also exists the chance the external unit of your air conditioner gets frozen or it frosts when it’s running in heat mode; this freezing will produce the same as happens in the external unit (cold mode), an ice layer in all the external exchanger, avoiding a good air exchange in it and therefore descending and diminishing capacity of our air conditioner. This symptom is less remarkable because the great majority of current air conditioners have defrost mode which avoids notoriously this to happen and its consequences, but also because of being this unit in the exterior, it is much more difficult to realize if air conditioner gets frozen on the external side.
  • Noise in the internal unit: In some occasions some crack noises are heard in the internal unit when ice from the machine defrosts, this doesn’t happen always, but it is a symptom the machine can give when something is not going the way it should be and it will indicate us our machine is either getting frozen or defrosting.

Internal unit with freezing beginning

In many occasions, if internal unit of air conditioner gets frozen, we associate it, as we have seen, with a water loss, but this is not the only reason of that dropping. If this is happening to you, you can see possible causes in this article:

Why does air conditioner loss water?

Ok, now I know symptoms, but what I’m interested to is why air conditioner gets frozen.

Causes why an air conditioner throws ice or it gets frozen

There are many causes which can produce this breakdown, ones aren’t really breakdowns but a lack of maintenance, others are caused by more or less serious breakdowns:

  • Dirty filters: the most common cause is to have a very very dirty air conditioner filters, and it is also the easiest to solve. This could be avoided if we had a correct maintenance of our unit, cleaning filters periodicly is how we avoid this breakdown; due to air flux can’t pass through filters because of dirtiness, it makes the machine to get frozen because it isn’t capable of throwing all the cold air is producing. The solution, as we mentioned above, is simple: to clean filters.

How to clean properly air conditioner filters

  • Dirty internal exchanger: As well as in filters’ case, a dirty exchanger produces the same effect, there isn’t enough air flux through the internal unit and it gets frozen progressively. This problem is due to a bad maintenance too, because if we maintain our air conditioner filters clean, these will avoid that dirtiness to pass through the exchanger and the problem to clean it.
  • The internal fan works badly or it is extremely dirty: If our internal fan doesn’t work the way it should be because of a failure on it or because it is so dirty that air can’t pass through its wings, this will produce us the same effect as dirty filters or a dirty exchanger and we will be wondering why my air conditioner gets frozen without finding a reason. Cleaning a fan is a complex task and it will be advisable to call SAT.

A very dirty internal fan may cause air conditioner gets frozen in its internal part

  • Lack of gas: That is one of the most common causes. A partial lack of gas (if the machine runs out of gas, it doesn’t throw cold air and it can’t get frozen) will produce our air conditioner gets frozen like a freezer, due to a gas pressure descent affects on a lower evaporation temperature (temperature in which refrigerant arrives in external unit), which makes the unit to get frozen. In heat mode this will occur the same way, but in this occasion the unit which will get frozen will be the external one. The solution in both cases will be to look for the leak, repair it and recharge gas.
  • External unit fan doesn’t work or it lacks ventilation: In heat mode if an external fan doesn’t work or it lacks ventilation, it will produce a freezing in the external exchanger or external machine. This problem may be caused because the fan itself fails or the electronical board doesn’t send current. It will be fixed by finding where the breakdown is and repairing it, in that case, a better option is to call SAT.
  • Very dirty external exchanger: This breakdown affects when unit is in heat mode, as we explained before, if the internal exchanger gets very dirty, a very dirty external exchanger can produce the external unit to get frozen. The solution in both cases is to clean this exchanger.
A very dirty air conditioner may affect in its capacity and in a possible external unit freezingmore
An external unit very dirty may end getting frozen due to a lack of air fluxmore

In view of these possible problems we should act according to reason; there are causes in which we should call SAT so it can manipulate machines or gives us a solution. In other cases like lack of maintenance or cleaning it its something we can fir ourselves if we know how to do it. If that is your case you may be interested in reading an article where we explain where filters are and how to clean them correctly.

How to clean air conditioner filters

To determine if your air conditioner lacks of gas, you can read an explanation of all possible symptoms of this very common breakdown:

How to find out if my air conditioner lacks of gas

To sum up, remember what you have to do when air conditioner gets frozen:

1 – Clean filters.

2 – Clean internal and external exchanger (heat mode).

3 – Clean internal fan.

4 – If all of this doesn’t solve the ice problem in air conditioner, it will be advisable to call SAT.

David Macías :