You go about your day-to-day life expecting your cooling system to cool and your heating system to heat when you want it to. Then one day, something goes wrong.
It’s hot in your house.
When you investigate, you discover that your air conditioner units have ice inside of them. Your condensation line or refrigerant lines might also be coated in frosty crystals.
As AC experts, it’s common for people to ask us, “Why is my air conditioner freezing up?” You don’t just want it fixed, you want to understand what happened and how you can possibly prevent it. Over the years, we have refined our answer to this question and want to share it with you.
The common reasons an air conditioner freezes up are:
- Thermostat settings
- Reduced airflow
- Blower fan or furnace fan
- Low refrigerant
Let’s break down these points in more detail.
Thermostat Settings
When a thermostat is set to an extremely low temperature, the cooling system runs continually to reach it. When the air conditioner is constantly cooling without breaks, it can become too cold.
This not only causes the unit to freeze, but it also creates unnecessary stress on the appliances, reducing their life.
So even though a thermostat will allow you to set it to whatever temperature you like, that doesn’t mean you should. In fact, a thermostat should never be set below 72 degrees.
Reduced Air Flow
When something causes the airflow to decrease around the evaporator coil, the refrigerant doesn’t absorb as much heat as it should be. There isn’t enough hot air around it for it to do its job. As a result, the refrigerant gradually becomes colder and colder.
The water that runs down the condensation line and leads outside will begin to freeze from the frigid temperatures. At first, you may not notice it, but over time, the ice will build up.
If left untreated, the ice can form down your refrigeration line and even around your entire condenser.
But what causes an air conditioner to experience reduced airflow?
There could be a number of reasons, including but not limited to:
- Dirty filter
- Too many closed vents
- Closed intake vents
- Blocked or covered vents
A little sleuthing is in order. Check your filter and change it if it is dirty. Examine every vent closely and make sure they are all open and free of obstructions.
The Fan
Inside your home, the furnace fan or blower fan pulls warm air through your intake vents and pushes it past the evaporator coils. The cold coils absorb the heat and cooler air results. But if the fan isn’t functioning properly or at all, warm air won’t flow over those coils.
Since they aren’t absorbing heat, the refrigerant doesn’t become warmer. Instead, the refrigerant will cause the unit to freeze in a matter of minutes.
Once a blower fan or furnace fan stops working, you’re left with a block of ice in your house.
It’s time to call in an expert to assess the fan motor and control board to figure out exactly what caused it to malfunction. Sometimes parts get old and wear out, but other factors could contribute to premature deterioration.
Professional installation and repair of air conditioner units and their parts will help your AC to last longer and run more efficiently.
Low Refrigerant
When the right amount of refrigerant is in your cooling system, it will be a few degrees above freezing. You may remember from our last blog post “How does an Air Conditioner work” that a fall in pressure causes a fall in temperature. More refrigerant creates more pressure, and less refrigerant will produce less pressure which is how we regulate its temperature.
When there isn’t enough refrigerant present in your AC unit, the pressure lowers, resulting in a drop in temperature that reaches below freezing. At this point, your air conditioner is no longer cooling.
Instead, it’s freezing everything around it, including the moisture that it’s pulling from the hot humid air. That condensation freezes on and around the unit parts, forming ice.
The only way to correct this issue is by calling in a professional so that they can add just enough refrigerant to your unit to return it to the optimum temperature.
What Do I Do If My Air Conditioner is Freezing Up?
The first thing you need to do is shut off your air conditioner and switch your fan to ON (not AUTO). Then place towels around your indoor unit to absorb the puddle that will form when the ice melts. This process may take up to two days.
If you have identified that the problem was related to thermostat settings or low airflow, and you corrected it. Go ahead and restart your unit when it has fully thawed.
But if your problem is more complex, you will need to call in a professional heating and cooling contractor like Action Air Conditioning to service your air conditioner. Besides the reasons we have already mentioned above, you could have a blockage in your metering device or a dirty evaporator coil.
Action Air Conditioning is ready to help you with all of your cooling system needs in the Tampa Bay area. Schedule an appointment with us today!