Three Reasons Your AC Coil May Freeze Over

When you realize that your AC coil is frozen over, there's no need to panic. However, you should shut off your unit and call an AC repair contractor at once. If you continue running it, the ice could spread and cause extremely expensive damage to the unit. But what caused the incident in the first place, you wonder? There are a number of reasons why your AC unit's evaporator coil may be frozen over, and here are three of the most common ones.

1. Overuse or overwork

If the unit isn't correctly sized, it will need to work harder to keep your house cool. And if the outside temperature is much higher than normal, the unit may have to work practically nonstop in order to keep your house down to the set temperature. Unfortunately, your AC unit wasn't designed to work constantly without a break, so either of these situations can result in an overworked unit. It's especially bad if your unit is slightly too small for your house and you're in the middle of a heat wave at the same time. Such overuse can keep the unit from being able to stabilize itself between cycles and may thus cause a malfunction that leads to frozen-over coils.  

2. Refrigerant leak

A refrigerant leak, you might think, should mean that the unit has less cooling power and therefore is less likely to freeze up. It's true that it'll have less cooling power (you may notice that the unit hasn't been cooling your house as efficiently as usual), but it actually makes the unit more likely to freeze up due to the way AC coils work. If this is the issue with your unit, your repair technician will be able to easily fix the problem by simply thawing the coil and then refilling the refrigerant (as long as you turned the unit off before the ice could spread to the compressor).  

3. Blocked coils

A dirty coil, like low refrigerant levels, can actually reduce the efficacy of your AC unit by physically blocking the coil from functioning properly. Fortunately, if you've been maintaining your unit regularly, you shouldn't have this problem. However, if you do suspect this to be the case, at least it'll be easy enough to fix. Another way the unit's efficacy may be blocked is if the airflow to the unit is blocked; an airflow blockage near the coil (perhaps caused by dense vegetation) or a blockage at an interior vent caused by a clogged filter could both affect the AC function.   These three problems can all be the catalyst for frozen AC coils and can all cause further damage to your unit as well if you don't have the problem remedied after thawing the coil.

For more information, contact an HVAC company like Don's AC Service, Inc.