Why is my HVAC Unit Freezing Up?

We’ve all been there – the dog days of summer arrive, we crank up the cold air, and…the AC stops working. While there could be many reasons for this, it seems people are most shocked when they walk outside and see a big block of ice sitting on their condenser coil. While it seems like a strange occurrence, it’s actually pretty common and can happen for a few reasons:

Poor air flow – if air is not blowing across your air conditioner’s coil, condensate will build and begin to form ice. Poor airflow typically stems from dirty filters or dirty coils, which make it harder for your fan and blower to pull air across the coils. Additionally, broken belts won’t move any air across your coils.

Low Refrigerant charge – if your system is low on refrigerant, the pressure within the system will be lower, thus resulting in a cooler refrigerant temperature. A system low on refrigerant is usually a telltale sign that there is a leak in the system. While the “quick fix” to this solution is to add more refrigerant to your system, this is only prolonging further repairs, and deferring repairs now will ultimately cost more in the long run. Caution: it is of paramount importance that a low charge is the issue; overcharging a compressor will result in inefficient operation and can lead to compressor failure!

So what can you do?

Fortunately, these issues are straightforward to identify and can be mitigated or outright prevented. Filters should be changed between monthly and quarterly (depending on whether your structure is a home, building or industrial plant) and coils should be cleaned thoroughly semi-annually. The easiest way to keep your system running its best is to hire a licensed HVAC contractor and establish a service contract that fits your needs.