If you have noticed an issue with your AC unit, especially during the heat of the summer, one main culprit is that the air conditioner may have frozen over. If your AC unit is icing up, you will be able to tell, even if you cannot see the ice. Place your hand over the supply register – does it seem like there is no airflow? The issue might be a frozen AC unit.
What causes your AC unit to freeze?
While it seems like only a cold front sweeping across the region could cause your air conditioner to freeze, there are actually several reasons that your ac unit might be freezing up. Air conditioner units require regular maintenance, and without that upkeep, they can sometimes malfunction. Here are several reasons your air conditioner is freezing:
Low Refrigerant Levels
Low refrigerant levels can make the evaporator coil too cold, causing the ac unit to freeze. This could be caused by a leak or if the refrigerant was charged incorrectly during AC installation. If this appears to be the cause, call an HVAC professional to fix the issue.
Dirty Air Filters
One of the main pieces of maintenance you should complete as a homeowner for your HVAC system is changing the air filter on a regular basis. Not doing so clogs up the airflow, which also adds stress to the air compressor and other components of the AC unit but can also negatively affect your home's indoor air quality. This, in turn, delivers less air to the evaporator coil, causing it to freeze.
Closed Supply Register
While shutting one register in an unused room may save you money, closing too many supply registers may cause freezing.
Insufficient Fan Speed
If the fan is not blowing fast enough, it may not be forcing enough air over the evaporator coil.
If the air conditioner is running more than is necessary or above its capacity, it may cause your air conditioner to freeze. This could be from someone cranking up the AC or an issue with the thermostat.
If condensation from the AC unit is backed up outside the condensation pan or floor drain, the backed up water may freeze all the way back to the evaporator coil, blocking additional drainage and worsening the problem. Make sure your drainage system is clear, especially during the hottest parts of the summer.
Window Unit Tilted Wrong
If you have a window AC unit, you will want to make sure the indoor portion is slightly higher than the outdoor portion, which will allow water to exit the drainage hold. If the unit is level or tilted the wrong way, water will get trapped in the unit, causing freezing.
Preventing Air Conditioner Freezing
As you can see, there are a lot of reasons that an AC unit might freeze. However, the good news is that with regular maintenance and some diligence on the part of the homeowner, you can prevent AC freezing in many cases. Here are some easy steps you can take to prevent your air conditioner from freezing:
Have the refrigerant level checked during regular maintenance
Change the filter monthly (or as often as your HVAC service provider recommends)
Keep more than 75 percent of supply vents open at all times.
Have your HVAC technician increase the fan speed if it is too slow
Keep the thermostat set to a reasonable level and do not force your AC unit to overwork
Inspect your condensate drain and other parts of your HVAC unit regularly to ensure there is not blockage
If you have a window unit, align it correctly
The Best Way To Prevent AC Units From Freezing
While there are some easy ways to prevent your AC unit from freezing as a homeowner, some of the preventative measures should be completed by a professional HVAC service technician. The best way to avoid any issues that cause an AC unit to freeze is to have regular maintenance performed on your HVAC system. This not only helps to keep the system running properly for many years to come, but a trained technician can also spot potential issues with your heating and cooling system, and get these fixed before they develop into problems. If you are ready to schedule your annual HVAC system maintenance, contact the team at Central Heating today.