Other than visible ice on any part of your HVAC unit, the next most obvious sign of a frozen AC unit is a lack of cool air. If you put your hand in front of your supply vents and you sense warm air coming out, you probably have ice somewhere in the system. You may also notice a hissing sound coming from the unit.
Continuing to run your air conditioning unit with frozen evaporator coils poses a significant risk, potentially leading to permanent damage to your entire cooling system. Neglecting to address and unfreeze the AC coils can result in system overheating, which may cause refrigerant leaks and damage to other components.
To unfreeze an air conditioner quickly, turn off the AC but leave the fan running. This allows warm air to circulate over the frozen coils, speeding up the defrosting process. Meanwhile, check for any blocked air filters or restricted airflow and replace or clean them if needed.
Once the AC unit has thawed completely, and you've done a check on the filters and the air registers. It is now time to fire the system on. Switch ON the thermostat and set it at COOL. If the AC is working correctly, the air registers should blow cold air into the room.
Well, the thawing process could take up to 24 hours depending on the size of your unit, the extent of the ice buildup, and the efficiency of your blower fan. If the freezing on your air conditioner was just starting, it could clear up faster in an hour or two.
Step 1: Turn OFF Your AC
We know, we know: It's hot. But frozen AC parts are bad news for the most expensive piece of your HVAC unit—the compressor. To avoid lasting damage and a hefty bill, turn your thermostat from COOL to OFF. This will start the defrosting process.
Whether you've confirmed for certain that you have frozen evaporator coils, or you just suspect it, you need to turn off your A/C. Then, your coils should be able to defrost, taking up to 24 hours to thaw out. You can also safely dry out the coils with a hair dryer.
First, check your filters and coils for dirt and debris that may be impeding airflow. Once you've cleaned the filters and coils, run the air conditioner with just the fan so that the ice accumulation can melt off. If the AC still doesn't blow cold air, it could be that refrigerant levels are too low.
Low refrigerant can also lead to frozen evaporator coils. Without refrigerant passing through the coils, there will be no way for that absorbed heat to be transferred out of the air handler. The lack of pressure within the coil continues to drop, the moisture freezes onto the coils, and ice forms as a result.
No, you should not run your AC with frozen coils. Operating the system while the coils are frozen can cause further damage to the unit, leading to costly repairs.
Signs of Damaged Evaporator Coil Components
Air coming from the vents is warm. Air conditioner starts and stops frequently but doesn't properly cool your home. Air conditioner does not turn on. Refrigerant leak near the indoor cooling system components.
If the AC frozen cause is a dirty air filter, the issue is something you can fix yourself. If you suspect something more severe, like an HVAC refrigerant leak, it's time to call an HVAC technician.
Once your air conditioner is ice-free, you can turn it back on and reset the fan to auto (This may take an hour or more).
When the filter becomes dirty, this can block airflow and cause the evaporator coil to get too cold, which can lead to a frozen AC unit. As a general rule of thumb, many HVAC professionals recommend replacing the air filter every 90 days.
If the thermostat malfunctions and detects the wrong temperature, this can cause your A/C to run too hard for long periods of time. If your A/C runs for too long it can cause the coils to freeze.
Yes, you should turn off your AC if it's not cooling.
Your AC unit has two coils: the evaporator coil and the condenser coil. The evaporator coil is located in the air handler unit (indoors) and absorbs the heat and humidity from your home. The condenser coil is located in the outdoor portion of your unit and releases that excess heat from your home to the outdoors.
The most common problems that cause a lack of airflow include frozen coils, broken fan and restricted airflow due to dirty air filters or vent obstruction. However, there are many other issues that can lead to minimal airflow, so it may be necessary to ask the professionals.
Most often, air conditioners freeze due to an obstructed airflow. AC's can also freeze due to a coolant leak, dirty evaporator coil, and dirty air filter. To prolong the lifetime of your air conditioner, you should call an HVAC professional after your air conditioner froze.