Allentown Air Conditioning Guide: What Causes My AC To Freeze Up?

HVAC repair experts and technician often get the question, “what causes my air conditioning to freeze up?” The basic answer is that a typical AC will freeze up whenever ice forms on the coils while the system is running and functioning. As soon as the ice begins to thicken on the coils, the system or unit will eventually shut down.

Be reminded that when the same  thing happens to your AC, it is very crucial to have it addressed and fixed immediately in order to avoid the likelihood of a more extensive and serious damage to your unit, which may eventually lead to complete breakdown, rendering it unusable.

So the first response on your part as soon as you see it freezing up is to turn it off. What you have to do is allow the air conditioning system to be turned off until the ice buildup melts completely. The waiting time should be around three hours or even longer. While you’re thawing the unit, you can start determining the cause of the ice formation on the coils. By knowing what caused it, you also know how to address it.

Common Causes

Blocked Air Flow – One very typical reason for freezing is blocked air flow. This happens when you have a clogged HVAC filter that results in the blocking of the passage of air to the system. When that clog is so thick and severe, what happens is that the unit will freeze because it will force itself to generate cool air without the essential and sufficient air flow.

Low Refrigerant – Another common cause for your AC to freeze up is when the unit has a very low refrigerant level. So what causes low refrigerant level? It actually happens when a leak is present in any of the components or parts of the system or the lines. When low refrigerant level is the cause, you cannot do the repair yourself. Instead, you need someone like an HVAC service technician to put in additional refrigerant and in the process look for the leak and fix it.

So these two are the main causes for your air conditioning to freeze up, but it doesn’t mean there are no other culprits. Yes, there are in fact other possible causes that you need to be aware of. For instance, there’s a chance for the AC to freeze when you’re using it on a particularly cold night. This happens especially when your thermostat is going out. If the temperature outside is cooler than the thermostat setting, ice will eventually form on the coils. Likewise, freezing can also happen when the blower fan of the unit is not running as fast as it should be. The thing is the fan should be fast enough in order to distribute sufficient cooled air. What you need to do then is simply switch the fan speed to a higher level and see if the freezing stops. If not, you have to call in the experts to get it adjusted or fixed.