If you don’t change your air filters and they are very dirty can this cause the central unit to freeze up? Will the unit be ok by changing the air filter? We had this happen 2 times before and we changed the filters. Our unit is only 2 years old.
Central Air Conditioner Icing Up
Ice forming on air conditioner coils is a common problem encountered by many home owners. This is usually attributed to poor air flow through the evaporator coil which creates low load conditions.
Two of the most common reasons for poor air flow:
- Dirty air filters
- Undersized ductwork
This results in evaporator coil temperatures being at or below the freezing point which is 32 degrees Fahrenheit (0 degrees Celsius). Normal evaporator operating temperatures for air conditioning equipment is above 32 degrees.
What To Do When Your Air Conditioner Ices Up
Usually all you have to do is set the thermostat set point above room temperature so the compressor doesn’t operate and this will allow the ice to melt.
A better way to do this, depending on the type of thermostat you have, is set the fan to operate continuously and turn the cooling off. This keeps warm air moving through the evaporator coil which melts the ice much faster.
Depending on how badly the unit is iced up, 30 minutes should do the job and 1 hour is even better to ensure all ice is gone.
Three Potential Problems Resulting From Evaporator Coils Icing Up
- If the ice becomes bad enough it can actually cause the tubing in the evaporator coil to collapse or break. This requires a service technician to repair and possibly a new evaporator coil will be needed or worse. As you can imagine this is an expensive fix.
- Another problem with allowing your air filter to become this dirty is, equipment operating efficiency drops dramatically. The air conditioner will require longer run times to maintain space temperature and operating costs increase. You are much better off changing your air conditioner filters regularly.
- There is also some risk of water damage when the ice melts. Often ice build up is bad enough to block drain openings and water overflows the condensate drain pan damaging walls, flooring and even ceilings if your air conditioner is located in your attic.
P.S. If you are not sure when your air conditioner filter is dirty enough to be changed try using an air filter change indicator. These simple devices are reliable and easy to install.