Five Signs that there could be a serious “Ice” problem with your HVAC unit.


So imagine, you’re sitting inside enjoying the cool AC on a hot day in Maui. For no apparent reason, it stops working. As you take a closer look, you find that there’s ice on your AC units’ refrigerant lines. You may think to yourself if this is normal or not. Unfortunately, having ice on your AC unit is not normal.

Your AC unit could be having a problem with the airflow over the evaporator coils being restricted or there could be low refrigerant levels.

Restricted Air Flow

If your AC unit doesn’t get enough air, the evaporator coil which cools the air, gets too cold and the unit will eventually freeze over. The evaporator coil is large web like structure of refrigerant coils which can reach temperatures as low as 10-20 degrees fahrenheit. If for some reason there is not enough warm air passing over the evaporator coils, it will ice over quickly with ice travelling along the refrigerant lines.  Ice will build quickly as humid air touches the coils, condenses and then freezes.


What May Cause Restricted Airflow

  1. Clogged air filters
  2. Collapsed air ducts
  3. Dirt that may be on your evaporator coil
  4. Problems with the blower fan
  5. Vents that may be closed or have blockage

Restricted air flow will cause the coils to drop below freezing, humidity in the air begins to collect on the coils creating a build up of ice on your HVAC unit. This is often the result of a dirty air filter but can also be caused by the filter itself being too restrictive or not enough return ducts.

Low Refrigerant Levels

HVAC units use a special chemical known as refrigerant that absorbs heat from inside a home and the heat is then transferred outside. However, if the levels of the refrigerant suddenly drops, the pressure of the refrigerant of the evaporator coil will drop also. If this pressure drops so will the temperature causing ice to build up on the evaporator coils. The culprit? A refrigerant leak.

What To Look As Signs of a Possible Refrigerant Leak

  1. You hear a hissing or bubbling noise along the refrigerant lines
  2. Warm air can be felt coming from the vents
  3. Your electric bill is slightly higher than normal

If you notice any of these signs immediately turn the setting of your thermostat from cool to off. Next turn the fan of the thermostat to on and wait at least 3 to 4 hours to allow the system to thaw out. But most importantly, if you suspect a refrigerant leak call your certified HVAC technician right away!

Your Evaporator Coil May Be Dirty

If the inside evaporator coil is dirty, it can cause a lack of airflow to travel across it and drops the temperature. This may cause the system to freeze and ice to build. Other problems that may be caused by a dirty evaporator coil can be what’s known as “Dirty Sock Syndrome”.

Should I Check Inside for Ice?

Much like a car, you can’t always tell what’s wrong until you can take a look under the hood or in this case inside. Ice that maybe inside your HVAC unit can cause serious damage and needs to be fixed by a professional right away. It’s pretty common for a unit to drip water while in use, but if a lot of water is dripping inside then that’s a major concern. A drip pan that is full indicates that there could be melted ice inside the unit. If you hear large chunks falling inside, much like when you defrost your freezer or fridge. Turn off the AC unit immediately if any of these problems arise and contact your technician.


Sometimes you’ve done all you can and it’s time to call in a certified HVAC Technician.

If you’re in need of a professional diagnosis or repairs because there may be ice on your HVAC units, contact the professionals at Scott’s Cooling. Don’t let a seemingly small problem become a bigger one. Call us now at (808) 877-3665 or visit us online at . We won’t hesitate!