How to Clean an Air Conditioner Unit

Your air conditioner or heat pump condenser must, by necessity, be located outside the home. This means it is exposed to wind, rain, snow, bugs, dogs, kids, plants, and assorted vermin. It can get dirty, and that can impact operation. Specifically, a dirty condenser can reduce its efficiency. That costs you money. Don't worry, we can tell you how to clean an air conditioner condenser to maintain performance and ensure long term reliability.

The Proper Method to Clean an Air Conditioner Outside Condenser

The right way to clean an air conditioner outside unit is a step-by-step process. This isn't like washing a car that can be accomplished by slopping some suds into a bucket and going to town with a sponge. This is a simple, but short, specific procedure to ensure a clean and proper functioning condenser.

Step One: Turn Off the Power

The absolute very first thing you must do to clean an air conditioner properly is TURN OFF THE POWER. There should be an exterior disconnect box on the side of your house near the condenser. Pop it open and pull the breaker.

If for some reason you live in a home without an exterior disconnect, you'll have to turn off the power from the main panel inside your house. Make sure that you do this. There is absolutely no reason to risk injury, death, or burning down your house.

Turn off the power.

Step Two: Remove the Top Grille and Sides

Your air conditioner condenser should have a grille and fan on the top side. You should only have to undo a few screws to remove this grille, and, carefully, ease the fan out. The fan will be wired to the condenser, so make sure you do not damage any of the wiring. Do not disconnect the fan from this wiring. We don't need to take the grille and fan completely away from the condenser. All we need to do is shift them to the side to access the interior.

Some air conditioner condensers may also have a protective grille around the sides of the unit. You should remove these as well, if you have them. If not, move on to step three.

Step Three: Interior Debris Removal

Now that you can see the inside of the condenser, it's time to conduct a quick trash inspection. Is there any debris like leaves, grass, or dirt built up on the bottom plate? Fish the big stuff out by hand. Whatever is left can be removed with a vacuum cleaner. A wet/dry vacuum would be the best tool for this.

Next, take a look at the coils themselves. Are there leaves or grass clippings stuck between the coils? That's bad, so remove it. In fact, remove anything big enough to grab by hand, and throw it away. Any kind of foreign material stuck between your coils is a bad thing.

Step Four: Coil Inspection & Foaming

You looked at the coils in step three, right? Well, we're going to do that again, but this time we're not looking for debris. Right now we're looking for any bent or mashed coils. Do you see a lot of them? You may need to invest in a fin comb. This is a simple tool that can be used to gently pull bent or mashed air conditioner coil fins back into place. Emphasis on gently. You want to be very careful when working in or around the coils, because damaging them is bad.

To finish step four you will need to apply a foaming condenser coil cleaner to the coils. What is a foaming condenser coil cleaner? It's a spray cleaner that you apply to air conditioner or heat pump coils. Basically, the foam gets in-between the coils and expands to push out any dirt and gunk stuck there. You should be able to buy this stuff at basically any hardware store. Get it, spray down the coil thoroughly.

Next, go do something else for about ten minutes. You need to give the foam time to do the job. Have you changed your air filter lately? No? Now's a great time.

Step Five: Rinse

Step five in the how to clean an air conditioner process is easy and fun. Go get your garden hose, and rinse away all the foam that's been expanding on the coils. Rinse from the inside out. You want to get the dirt out of the condenser, after all.

Do not use a high pressure washer to clean the coils! Those fins are way more delicate than you think. A pressure washer is going to smash and bend them. Which is bad. Do not do bad. Your garden hose is perfectly fine.

When you've thoroughly rinsed off all the foam by spraying from the interior, you can rinse of the exterior. 

Step Six: Area Problem Removal

Your yard is a potential hazard for an air conditioner condenser. Plants that want to grow towards our unit can cause damage. Spend a few minutes checking the area around the condenser base pad. Trim back any tall grass or vines angling toward our outdoor friend.

Do you have hedges nearby? Hedges love to grow into a condenser to mess up the fins. Trim back those hedges. The last thing you need is some uppity shrub ruining your home energy efficiency.

Step Seven: Reactivation

You have now essentially finished the ideal process by which to clean an air conditioner unit. It's time to start putting things back together. The first thing you will do is reattach any disconnected side grilles, and then replace the top grille and fan. Inspect the fan wires to make sure everything is where it should be.

Finally, you can turn the power back on from the main breaker or from the outside disconnect switch. And you're done! You've completed the requisite spring cleaning, and now your air conditioner condenser should run smoothly all summer long.

Still Got Questions?

Do you have questions or comments about how to properly clean an air conditioner unit? Or maybe you have a different question about the HVAC industry. Either way, let us know in the comments below. You can also follow Ingram's Water & Air Equipment on Facebook and Twitter. Send us a message directly here.

2 comments (view/add)
  • Stephen Neptune
    Stephen Neptune
    Posted on 6/1/2021

    Reading is fine, but I'd love to see some pictures included of what you're referring to Dan... and a video demonstration would be even better!

  • Dan Danowski
    Dan Danowski from Ingrams
    Posted on 6/1/2021

    We'll see what we can do.

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