Worn seals, punctures or other breaches in your vehicle's AC system, though, can cause contaminants like environmental moisture to enter the AC system. As moisture builds up inside of your vehicle's AC system, one or more of the AC lines may freeze up.
If your car AC lines are freezing up, you (or a professional tech) will need to remove the moisture that's causing it. After performing leak detection, recover the refrigerant from the system and make any necessary repairs/replacements to parts such as O-rings, hoses, lines or evaporators.
Dirty air filters that are clogged with debris can make it hard for air to flow properly. Try to change out your air conditioner's filter at least once a month to prevent condensation from forming and freezing on your evaporator coils.
It is usually caused by either moisture in the system or a lack of air flow going through your evaporator core which allows the condensation to freeze on the evaporator core if there is not sufficient enough air flow.
To unclog an AC drain line, turn off the power to the unit. Locate the drain line and use a wet/dry vacuum to suck out the clog. Flush the line with water using a garden hose or cup of water. Check and clean the drain pan under the indoor unit.
Clogs in the condensate drain line cause moisture to back up in the air conditioner, which can be damaging. The repair cost to have the drain line flushed runs between $75 to $250. If replacement is needed because the condensate drain line is damaged, a new condensate drain line is usually only around $20.
As always, turn the air conditioner off as soon as you notice freezing. Keep the fan on, though, so it will blow warm air over the frozen components. This will help thaw your system within a few hours in most cases. From there, the first step is to check your air filter and return vents.
Your AC has a drain hose that directs excess moisture away from the evaporator coils and out the undercarriage. If this hose is clogged, condensation will accumulate in the unit and begin dripping into the cabin.
Without airflow, heat doesn't get to the evaporator coil, and the refrigerant doesn't boil. As a result, the pressure and the temperature will drop, causing the system to freeze. If the filter you're using is too restrictive, it can cause the same problem.
As mentioned above, setting your thermostat too low—especially on humid days—can be an easy way to freeze up your AC. Aim to maintain a minimum temperature of 68 degrees to reduce the risk of a frozen air conditioner on a hot summer day.
Use Antifreeze
Adding antifreeze solutions to the air brake system lowers the freezing point of moisture and helps prevent the formation of ice within the air lines.
So, if you have ice building on your AC refrigerant lines, you have one of the following 2 problems: Restricted airflow over evaporator coils. Low refrigerant levels.
It's likely a blocked air flow problem. The first thing you need to do is turn off the air conditioner and let it defrost. After it's had sufficient time to thaw (1-3 hours), turn on just the fan for about an hour. Use this time to change your air filter.
When an evaporator coil becomes dirty or breaks, it cannot sufficiently draw in heat. As a result, it becomes too cold, leading to frozen AC lines. To fix the problem, you'll need to replace the evaporator coil.
If you've noticed a frozen AC line when inspecting your vehicle's engine bay, clogged condenser fins could be to blame. The condenser is a piece of cooling equipment that's responsible for releasing heat. You can typically find it either in front of or behind your vehicle's radiator.
AC repair costs can vary widely, depending on the cause of the problem and the type of vehicle. On average, car AC repair costs run between about $430 and $520. However, if you need a new compressor, you can expect to spend $1,300 to $2,500 or more.
1st Step: Turn Your HVAC Unit Off.
Even if it's sweltering outside, you still need to turn OFF your air conditioner! Running a frozen air conditioner will wear out parts much faster, and could overheat your unit. Worn parts are bad news for the most expensive piece of your HVAC unit—the compressor.
Turn the Unit Off
The simplest way to defrost an AC unit is to just turn it off for a few hours. Frosting results from AC operation, so turning the unit off gives any ice some time to melt naturally. We do not recommend trying to scrape the ice off the unit manually.
A warning sign that your car's condensate drain might be blocked is when you notice the water leaking inside your vehicle. If you find your car's floor getting wet with water whenever you turn your car's air conditioner on, then it's time to check your condensate drain.
The actual leak repair depends on the component that's leaking. A simple O-ring can cost just a few dollars plus labour, but a new air conditioning line or condenser can cost hundreds of dollars. All-in, you can expect to pay $150 to $1,000 or more for a leak repair.
AC is Producing Warm Air
One of the surefire signs of a clogged refrigerant line is if you notice the AC producing warm air when you expect cold air. The warm air is caused by a problem with the proper circulation of the refrigerant fluid, which is instrumental in cooling the air.