How to Clean Your Air Conditioner

If you notice your central air conditioning unit working a little harder these days, there’s a good chance that your beautiful piece of equipment needs a little TLC in the cleaning department. An air conditioner, after all, lives outside and is susceptible to the elements, dust, bugs, leaves … the list goes on.

We recommend that you fully clean your air conditioning unit at least once per year, typically at the start of spring, and then a quick clean-up near the end of fall before winter rolls in.

Why is that? Because regularly cleaning your AC unit keeps it running efficiently. In return, your utility bill stays low and the lifespan of your unit extends because parts aren’t wearing down as quickly from overwork.

Unfortunately, cleaning an air conditioning unit isn’t as easy as dusting the living room or wiping down a bathroom. If you’re not interested in learning exactly how to do it, request an AC maintenance appointment with One Hour Heating & Air Conditioning and go on with your day!

But for those who are interested in going it alone, here’s a …

Step-by-Step Guide for How to Clean an Air Conditioner

If you don’t plan on hiring a pro for this job, plan on blocking off a good chunk of your day to properly clean your air conditioning unit. Here’s the main cleaning process:

  • Turn off power to the AC unit from your breaker box
  • Open up your AC unit, which requires basic tools
  • Clean the evaporator coils
  • Clean the drain pan
  • Make sure the air conditioner drain isn’t clogged
  • Close up your AC unit.


1. How to Turn off AC

For safety reasons, the first—and most important step—is cutting power to your AC unit. An air conditioning unit uses a high amount of electricity to run (220- or 240-volt circuits), which is quite dangerous if you’re not careful.

First, make sure your AC isn’t operating by turning it off at the thermostat. Then go to your circuit breaker panel and turn off the breaker that’s connected to the outlet where your AC is plugged into. (This will cut the electricity flowing to your AC.)

2. How to Open AC Unit 

You need to open the door on your outdoor AC blower unit in order to access the evaporator coils, which is the first thing you’re going to clean. Depending on your unit, you may need to remove foil duct tape before removing the screws that keep the door in place. Please note, doing this yourself may void the warranty on your unit, so only proceed if you have confirmed this is not the case.

3. How to Clean Air Conditioner Coils: Three Ways

Your AC’s evaporator coils are responsible for cooling down your house. Typically made of copper, these coils capture the heat from inside your home and then provide the cool air that’s blown through your home’s ductwork. They’re also critical to the evaporation process. On humid days, water condenses on the coils and is removed from inside your home.

That’s why it’s so important to keep these coils clean. Dirty coils consume 30% more energy compared to clean coils.

With the AC unit door open, you can clean your unit’s evaporator coils. There are a handful of ways to clean AC coils. We’ve included them all, which means you’ll need the following tools:

  • Soft brush for dusting off coils
  • Coil cleaner spray, which is readily available at hardware stores
  • Compressed air for harder-to-reach debris
  • Dish soap and warm water


1. Brush Cleaning 

This is the easiest way to clean coils that aren’t too dirty. Make sure you’re using a soft-bristle brush that won’t scratch up the coils, but something firm enough that can take away any grime that’s stuck on the coils.

Scrub in a back-and-forth motion until all dirt and debris are removed.

2. Air Compressor Cleaning

If you have access to a portable air compressor, this is a powerful yet safe way to remove dirt and debris from your evaporator coils. Direct the air nozzle at the coil from the cleaner side to the dirtier side. It’s important to maintain consistent air pressure in order for this cleaning method to be effective. Make sure you’re wearing eye protection.

3. Warm Water and Detergent

Any standard dish soap, mixed with warm water should do the trick on really grimy coils. We recommend mixing the water and detergent in a spray bottle and then applying it to the coils.

Before using a soft brush to scrub away the grime, give the solution a few seconds to settle in and break up the debris. Rinse any soapy water off the coils when you’re done scrubbing.

Once the coils are free of debris and sparkling clean, it’s time to tackle the rest of the AC.

4. Check the Drain Plug

The drain plug allows your AC unit to remove condensation from your home on humid days, and without regular cleaning, it can become clogged. The most common culprit of clogs is algae and mold that build up over time.

While many modern AC units can detect a clog and stop operating until it’s cleared, older units will keep operating. When this happens, water will begin dripping through your ceiling or even out of your vents because it has nowhere else to go. If this has happened to you, turn off your AC immediately and call an HVAC professional.

To unclog a drain plug, find the drip pan on your unit which is usually located at the bottom. Slide it out and then use a wet/dry vac to remove all of the water. To actually unclog it, you can try using the vacuum, but an air compressor is typically the more effective option, as it tends to be more powerful.

If the air compressor can’t force out the clog from one end to the other, it’s time to call a professional to help.

5. Clean Around Your AC Unit 

Feel free to use a hose to spray away dirt and cobwebs that have made their way onto the outside of your unit. While it may seem minor, anything obstructing airflow is causing your AC unit to work harder.

Don’t forget to check near the base of your AC unit. Dirt can settle underneath and make the entire unit unlevel. Over time, this can do a number on the AC unit and lead to repairs down the road.

6. Replace Your AC Filters

The final step is replacing the filter on your air conditioning unit. It’s best to replace these filters every 3 months, especially if you have pets that shed often.

Ductless mini-splits feature their own filters, which can be vacuumed and soaked to remove debris.

Clean Your AC Today

Cleaning your air conditioning unit is a twice-a-year task that you need to be diligent about performing. If not, dirt and grime can lead to repairs down the road and reduce the life expectancy of your unit.

If you’ve never cleaned your AC before and the dirt and grime are really bad, it’s best to call an HVAC professional who can make it work optimally all summer (and all year) long.

For professional AC cleaning and maintenance, contact One Hour Heating & Air Conditioning today.