The Best Way to Clean Your AC Unit and Coils (And Save Money Doing It!)
Is your AC not cooling like it used to? You might be surprised to learn that dirty coils could be the reason why. When your AC coils are clogged with grime and debris, your unit has to work harder, which means higher energy bills—and less chill when you need it most.
Here’s how to deep clean your AC unit and coils the right way (without damaging anything), so your system runs efficiently all summer long.
Also…everything you’ll need to get the job done can be found HERE.
Step 1: Turn Off the Power (Seriously, Don’t Skip This)
Before you do anything, turn off the power to your AC unit. You’ll usually find a breaker box right next to the unit. Open the hatch and look for the breaker switch—if it’s in the ON position, carefully pull it out. Sometimes it sticks, so just be gentle.
💡 Pro Tip: Place the breaker on top of the unit or store it in a safe spot so you don’t forget to put it back when you're done.
And don’t forget to shut the breaker box door—nobody wants water mixing with electricity.
Step 2: Remove the Top (Carefully!)
Every AC unit is a bit different, so if you’re unsure how to remove the top, do a quick Google search using your unit’s make and model. For most units, there are screws around the top—remove those so you can access the inside.
⚠️ Important: The fan and wiring are often still attached to the top, so don’t yank it off. Prop it up gently or grab a buddy to help hold it steady while you work.
Step 3: Vacuum Out the Debris
Grab a shop vac and get to work removing leaves, twigs, and other junk that’s collected inside. Be extra careful around the delicate fins along the coils—they bend super easily, and damaged fins can reduce your system’s efficiency.
While you’re at it, check the drain holes along the bottom of the unit. If they’re clogged with mud, don’t worry—we’ll flush them out later. Just make sure they’re clear by the end.
🚫 IMPORTANT NOTE: Be sure to toss any loose dust/debris that you pull off the coils far away from the unit when cleaning. The AC will suck that right back in if you toss it right next to the coils. Clean up any debris completely.
Step 4: Spray On the Coil Cleaner
Now for the satisfying part. (NOTE: if you have some really built up debris, you can either use an HVAC Fin Comb, a ShopVac with a soft bristle brush attachment, or even a soft bristle tooth brush - just be sure to go slow and not damage the soft metal fins.)
I like using a foaming cleaner like the Simple Green AC Coil Cleaner (linked here). These are designed specifically for the job and cling to the coils long enough to break down gunk effectively.
Start at the top of the coils and work your way down, focusing on extra-dirty spots. Let it foam up and sit for 10–15 minutes. This “dwell time” is key—let the cleaner do the work for you.
If you’ve got a dual-wall AC unit, spray both layers (inside and outside) for the best results.
Step 5: Rinse Gently from the Inside Out
Once the cleaner has done its job, it’s rinse time. Use a garden hose with a gentle setting like “fan” or “shower.” Never use a pressure washer—it’ll bend those delicate fins and ruin the whole job.
Spray from the inside out to push debris away from the unit. Take your time and be thorough.
Even if your cleaner says “no rinse,” I always rinse anyway to avoid leaving behind any sticky residue that could attract more dirt.
👟 Pro Tip: Wear waterproof shoes. Trust me.
Step 6: Reassemble and Power Back On
Now that everything’s clean and sparkling, carefully reattach the top—making sure wires aren’t pinched and fan blades aren’t bent. Line up the screw holes and secure it in place.
Slide the breaker back in, flip it to “ON,” and boom—your AC unit is refreshed and ready to run like a champ.
⏱ Total Time: ~ 45 minutes
🧼 Recommended Frequency: Once a year (or more if you live in a dusty area)
Final Thoughts: It Won’t Be Perfect, But It’ll Be Better
This unit sits outside, so it’ll never look brand new again—and that’s okay! You might notice some fading or discoloration where grime used to be. That’s just wear and tear from the elements, and it’s totally normal.
The important thing? Your coils are clean, your AC is running better, and your wallet is breathing a sigh of relief.
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