How To Flush AC System With Alcohol?

Only a few things are more frustrating than a faulty AC, especially during summer. It should not be much of a problem because many times, all your car AC requires is a system flush to get it back to its perfect cooling state.

It involves flushing your AC system with alcohol to restore the cooling system to its peak performance.

A buildup of dust and dirt might have clogged your AC unit; therefore, flushing the system with a suitable solvent will help put your AC in a better working condition. Also, flushing your AC system as often as needed would prevent future damage caused by excessive dirt buildup.

What You Need?

Before flushing the AC system, you must ensure that you identify certain parts that must not come in contact with the alcohol.What You Need to Flush AC System With Alcohol

The compressor and accumulator, for example, should be left out of the flushing process. Also, it would be best if you never allow alcohol to enter the expansion valve and the orifice tube.

Ensure that you use the necessary protective gear before you begin to flush your AC system. Wear appropriate gloves and eyewear to protect yourself from harm.

You need some necessary tools for this process that would make your job seamless. These are:

  • Air compressor
  • Refrigerant recovery machine
  • Necessary lubricants
  • Adjustable wrench

You will also need other items such as a container to keep dirt or a rag to clean alcohol spills. When all these are in place, you can begin the flushing process.

5 Steps to Flush AC System With Alcohol

Drain the Refrigerant

Before starting the flushing process, you should first drain the refrigerant in your car AC. Do so by following the necessary guidelines from the manufacturer. You should find a valve in the system, then open it to allow the refrigerant to drain away. The valve’s location depends on your car brand and model, so please check the user manual that came with your car or check to Drain the Refrigerant of car ac system

Disconnect Hoses and Components

After draining the refrigerant, the next thing to do is to disconnect the AC system parts. Take out the orifice tube first. Then, remove the condenser, evaporator, and every other item that may obstruct your work. After disconnecting all the parts, you can begin the flushing process.Disconnect Hoses and Components

Flush the Condenser with Alcohol-Based Solvent

Locate the condenser’s inlet and pour in the alcohol-based solvent. Then, using an air compressor, feed compressed air into the condenser. This compressed air and denatured alcohol push out debris lodged inside the compressor through the outlet. Continue this process until the flushed-out alcohol is clean and contains no dirt. One helpful tip is to flush alcohol through both the inlet and the outlet repeatedly until you flush out all traces of dirt.

Flush the Evaporator

Carry out the same flushing process on the AC evaporator, ensuring that it is entirely dirt-free. Also, ensure you flush through the inlet and outlet until the alcohol that comes out on the other end no longer contains dirt.

Reassemble the AC System

After you’ve ensured that there is no trace of dirt in your AC system, reassemble the AC parts you disconnected earlier. Replace the refrigerant and then connect all other components and tubes. Finally, test run your AC to check that it is working perfectly.

Read Also: How Cold Should My AC Be?

Useful Tips

Avoid Alcohol Spillage

Flushing the condenser and evaporator would cause alcohol and debris to be flushed from the outlets. Always have a cleaning cloth ready or any other suitable item to collect the dirt.

Look Out for Leaks

You can spot leaks during the flushing process. Once you spot a leak, wrapping it up with duct tape will help seal the hole.

Air-dry AC Components

Denatured alcohol as a flushing solvent leaves minimal to no residue on the AC components. However, to ensure that all parts and components are completely dry, leave them out to air-dry before reassembling.

Replace AC Parts

It’s also vital that you use the opportunity to replace parts and components of your AC due for replacement. It would be best if you considered changing parts of the AC system, like the filter drier, every two years. Thus if your drier is due for replacement, it would be smart to replace it while flushing your AC system. You might also need to change the orifice tube and accumulator if you observe signs of wear.

    Lubricate Essential Parts

Lastly, remember to lubricate all the necessary parts with the right amount of oil as recommended by the manufacturer.

Learn More: Does Your Car AC Use Gas?

Frequently Asked Questions

Is Flushing My Ac System with Alcohol Safe?

Flushing with solvents can present some safety hazards. This explains why some original equipment manufacturers do not advise users to flush AC systems with solvents.

However, you can observe some safety precautions to avoid safety issues. It would help if you used protective wear while flushing out your AC system. Goggles and gloves are basic protective gear to use for the task. Also, ensure that you thoroughly read through the safety instructions for whichever solvent you choose to use. Lastly, ensure you’re carrying out this project in a well-ventilated area.

What Can I Use to Flush My Ac System?

The best solvent to use in flushing your AC system is one that leaves no residue behind. The solvent should also be one that evaporates at room temperature. For most people, denatured alcohol does the job excellently. It evaporates at room temperature and does not leave a residue. Although there are solvents specially made to flush AC systems, they are relatively expensive. Denatured alcohol does an equally great job of flushing out debris from your AC system and is affordable. While alcohol is mainly preferred for final flushing, it’s also very popular for all-around flushing. However, some people also opt for mineral spirits or brake cleaners.

Can You Use Mineral Spirits to Flush the Ac System?

Mineral spirits do not evaporate easily because the content has a high boiling point, and this might cause residue to remain on your AC components. Also, mineral spirits may leave residue in essential AC components that can cause severe damage to your AC system. They are highly flammable, so you must use them with care. Therefore original equipment manufacturers do not recommend using mineral spirits for flushing AC systems. You may void your warranty if you go ahead to use it.

However, many car owners and technicians have mastered the use of mineral spirits for flushing AC systems without problems.

How Do I Know when My Ac System Needs Flushing?

Your AC system should be flushed if you have reasons to open the system often. Also, if you have not used the car AC for a long time and the refrigerant level is low, you should make arrangements to flush the AC system before any attempt to use it.

While driving around, there’s a huge chance that contaminants and dirt will enter the AC system over time. AC compressors are quite expensive so you should try to keep them performing optimally. If you do not flush the AC system, debris will continue to circulate and cause the compressor to fail.


Getting your car AC back in top performance might be as simple as flushing the AC system with denatured alcohol. This article discussed how you could flush your AC system with alcohol.

All in all, you need to flush your car AC system periodically so you can continue to enjoy its performance and avoid more expensive repairs in the future. This makes for an interesting DIY project. However, if you are unsure how to go about any part of the process, you might want to call a car AC technician instead.