While you may expect ice everywhere to beat Melbourne’s hot summer day, like in your juice or iced latte, and even in your home to stay cool, you’d want ice to stay away from the air conditioning unit. Your air conditioner unit icing up can leave you boiling without any coolness for a day or more!
Although the air conditioning unit icing up is a slow, gradual process, its visible symptoms appear suddenly. It’s more like a slow leak in the tire. It’s there but unnoticeable until it becomes evident and urgent.
While you may not be able to get a clear answer to why this happens, air conditioning experts say that if you keep an eye on the early signs of the air conditioning unit icing up, know the common causes, and take appropriate measures, you can save your AC unit from icing up. Saving the AC unit from icing up means no AC breakdowns and smooth cooling during summer.
Let’s start by understanding what an air conditioning unit icing up is.
What Is The Air Conditioning Unit Icing Up?
The term, “air conditioning icing up” refers to ice or frost building inside the air conditioning unit. Icing or frosting usually builds up on internal AC components such as the evaporator coil, refrigerant lines and in the worst case, the frost or ice is also present in the outdoor unit.
Ice builds up on these AC components when they get too cold. When warm air passes over them, the moisture in the air freezes instead of evaporating, causing the ice to form.
What Are The Early Signs Of An Air Conditioning Unit Icing Up?
The early signs that an air conditioning system shows up to tell about ice forming within the system include:
- Air flow from the vents feels weaker than usual.
- The AC is not cooling the room as usual. The room’s temperature stays warmer than the temperature set on the thermostat.
- The AC takes longer than normal to cool the room.
- Slight hissing or gurgling sounds from the AC unit.
- Unusual water drips or condensation around the indoor units.
- Visible frost forming on the copper pipes near the indoor unit or outside.
- The air filters keep clogging early.
Why Does The Air Conditioning Unit Ice Up?
Building up frost or ice inside the air conditioning unit is not normal. Ice inside the system clearly indicates an underlying issue. There is no one specific answer to why the air conditioning unit ices up; rather, there are multiple reasons behind the icing problem in the system, which are responsible for this problem alone or collectively cause icing.
These underlying issues disturb how the air conditioning system works and affect its operational efficiency.
5 Common Causes of Air Conditioning Unit Icing Up
While there are many causes of ice building up in the air conditioner, the five most common ones are listed here:
1. Low Refrigerant Levels
The refrigerant levels in each air conditioning unit vary depending on the type, model, and size. The levels also vary when AC is turned off or is in use. Maintaining refrigerant levels within manufacturer’s provided limits is necessary as lower or high refrigerant levels can cause system failure.
How do refrigerant levels cause an air conditioning unit icing up?
The refrigerant absorbs heat from indoor air and releases it outside. When the refrigerant level is low, the pressure in the AC system drops, and the refrigerant becomes cooler than usual. Due to the coolness of the refrigerant, moisture in the air freezes on the evaporator coil, causing ice buildup.
Signs of Low Refrigerant Levels:
- Weekend airflow from the vents.
- Ice on the indoor coil or copper refrigerant lines.
- The AC is running continuously, but not cooling the room.
- Hissing and bubbling sounds indicate refrigerant leakage.
2. Airflow Restrictions
Air conditioners require unrestricted airflow for efficient performance. Restricted airflow causes many problems in the AC unit, including ice buildup. Restricted airflow is one of the most common and preventable causes of ice buildup.
Dirty filters, blocked or closed vents or registers, obstructed return air grilles, a malfunctioning fan or blower motor, and a dirty evaporator coil are common causes of airflow restrictions.
Leading air conditioner brand Haier enlists airflow restrictions as one of the most common causes for ice buildup.
How do airflow restrictions cause an air conditioning unit icing up?
AC depends on warm indoor air passing over the evaporator coil to absorb heat. When warm air cannot reach the evaporator coil due to blockages or clogs, the evaporator coil becomes too cold. The moisture that usually cools down the evaporator coil freezes on it, causing ice buildup.
Signs of Airflow Restrictions:
- Weak or no air from vents.
- Ice on the evaporator coil or copper lines.
- The AC blows warm air instead of cool.
- Buzzing or whirring sounds from the blower fan.
3. Faulty Thermostat
The thermostat is one of the main components that control temperature and signal the AC to turn off or on for indoor temperature maintenance. A faulty thermostat can’t signal the AC unit properly to turn off after reaching the desired temperature and this causes problems for the AC unit.
How does a faulty thermostat cause an air conditioning unit icing up?
When a thermostat malfunctions, it doesn’t turn off the AC unit, causing it to run for extended periods. Constant operations cause the evaporator coil to cool down, and ice builds up. The condition worsens if airflow restrictions accompany it.
Signs of a Faulty Thermostat:
- Inaccurate temperature readings.
- AC runs nonstop.
- The room feels cooler than the desired temperature settings.
- The thermostat doesn't respond appropriately when changing the temperature settings.
- Ice builds up on the evaporator coil and copper pipes.
4. Dirty Internal Components
Dust and debris are detrimental to the air conditioning unit. They affect the system’s performance, efficiency, and longevity. When the internal components get dirty, they disrupt the airflow, cause problems with the heat exchange, and cause ice buildup.
How do dirty internal components cause an air conditioning unit icing up?
- Dirty evaporator coils can not exchange heat effectively. Without heat, it gets too cold and causes moisture to freeze over the evaporator coil.
- If the blower wheel or fan blades are dirty, they can not push enough air towards the evaporator coil, causing its temperature to drop. When the evaporator gets too cold, the moisture starts to freeze.
- Dirt and mixture clog the condensate drain, trapping humidity inside the AC unit. This increases the moisture around the evaporator coil and leads to more ice formation.
Signs of Dirty Internal Components:
- Weak or inconsistent airflow.
- AC takes too long to cool the room.
- Musty or burnt smells.
- Ice or frost on copper lines or coils.
5. Blower Motor Or Fan Motor Issues
The blower and fan motors circulate air inside the air conditioning unit. They have slightly different roles. The blower motor supports the indoor blower fan, which pulls warm air from the indoor spaces. The outdoor fan motor draws in outdoor air across the condenser coil.
How do a blower motor or fan motor cause an air conditioning unit icing up?
If the blower or fan motor isn’t functioning correctly, the airflow towards the evaporator coil is reduced. Disrupted airflow disturbs the heat exchange mechanism at the evaporator coil and causes humidity to build up.
Signs of Blower and Fan Issues:
- The AC blows warm air.
- Airflow weakens or stops altogether.
- The system overheats and shuts down.
How To Prevent An Air Conditioning System From Icing Up?
Icing up the air conditioning system is a serious problem, and you must take measures to prevent it from happening or worsening.
When you detect the early signs of ice buildup, take preventive measures to save the AC unit from further damage.
Turn off the AC unit:
As soon as you feel that your air conditioning unit is having problems and you suspect ice is building up, turn it off. Keeping the AC on will worsen the condition and damage the internal components, especially the compressor.
Turn On The "Fan Only"
Close the cooling mode and turn on the fan only to melt the ice.
Clean The Dirty Internal Components:
Clean the filters, evaporator coil, and all dirty components accessible, such as condensate pipes. This will decrease the ice buildup process.
Manage The Refrigerant:
Check the refrigerant level and pressure to ensure no problems with the refrigerant.
Seasonal AC Unit Maintenance:
Scheduling maintenance before the summer season ensures your AC unit is ready to offer cooling services. To get detailed information on season AC unit maintenance, refer to our complete guide on seasonal HVAC maintenance or contact Surrey Air to call a professional for help.
Final Verdict:
Air conditioning unit icing up is a serious issue affecting the AC unit’s function and longevity. You must keep an eye on your AC unit’s performance, noise, water drips, and ice buildups to catch the problem early. Mostly, the causes of ice buildup are preventable and you can protect your AC unit from failure.
The most common causes of an air conditioning unit icing up include low refrigerant levels, airflow restrictions, a faulty thermostat, dirty internal components and issues with blower motors and fan motors. You can prevent the air conditioning unit from icing up by turning off the AC, using the fan-only option to melt the ice, keeping the AC unit clean, managing the refrigerant levels and scheduling seasonal maintenance services.
