Annual maintenance will help maximize your air conditioner’s performance. Photo: Kelly Plumbing & Heating, Inc. (2017)

Your air conditioner is designed to keep your home cool during the summer, but like any system, it requires ongoing maintenance to sustain peak operating efficiency. While some maintenance steps are best left to an HVAC professional (such as handling refrigerant), there are others you can perform yourself. Here are four DIY air conditioning maintenance steps:

1. Change the air filter. Before turning on your air conditioner for the season, inspect the air filter and replace it as needed. A new air filter will provide cleaner, fresher indoor air in addition to optimizing airflow and general system performance.

2. Clean the condenser. Since it’s located outside, an air conditioner’s condenser can accumulate dirt and debris over time, which can inhibit efficient performance. For this reason, it’s good to do some basic cleaning before turning it on for the summer. After shutting off power to the unit, remove the fan cage and use a broom or compressed air source to clean out any leaves, cobwebs, and other debris. This is also a good time to trim or remove any encroaching shrubs or weeds, which will ensure the condenser is able to “breathe.”


Before cleaning your air conditioner’s exterior condenser, be sure to shut off power to the unit. Photo: Valley Heating, Cooling and Electrical (2017)

Next, clean the condenser coils, which comprise the unit’s grill-like outer walls. After using a brush to remove loose dirt buildup, spray the coils with a commercial coil cleaner. Allow the cleaner to remain on the coils for five to 10 minutes before rinsing them off with a hose. If any of the coil fins appear bent, you can straighten them using a coil fin brush.

3. Clean the evaporator coil. As the part of your air conditioning system where refrigerant absorbs heat to produce cold air, your evaporator coil should be cleaned periodically to facilitate this critical function. To access the evaporator coil, open the door to the blower unit (you may need to remove a few screws and/or some duct tape). After dusting off the coil with a soft-bristled brush, spray it with your commercial coil cleaner. Unlike the previous application, there’s no need to rinse the cleaner off the coil—after initially foaming up, it will simply drain into the condensate drip pan.

4. Clean the condensate drain. As an air conditioner runs, condensed moisture and water vapor are channeled through the condensate drain to a termination point outside the home. Over time, this drain can become clogged with algae and sludge buildup, so it’s good to periodically clear the line. Locate the drain termination point (look for a PVC pipe protruding from your home’s foundation) and use a wet/dry vacuum to clean out any latent buildup. Other techniques include running a long wire through the line or flushing it with a bleach and water solution.

While any of the aforementioned steps can be performed independently, if you don’t feel comfortable doing them yourself, you should call a professional to handle them for you. To find a Diamond Certified HVAC company in your area, visit

47 Responses

  1. Lily de Grey says:

    Great article, James! I’m always looking for ways to improve the efficiency of my home’s cooling. I think you’ve brought up a valuable point: It’s important to change the air filter regularly. I checked my filter earlier this week, and it was full of dirt! I cannot imagine that circulating around my house. Thanks for these helpful tips; I’m sure my energy bill will be lowered in no time!

  2. I only knew the change the air filter, so this post was really informative. I must have wasted a lot of money having contractors out here to do what I could have done on my own air conditioning unit 🙁 It’s all a learning experience, though. Thanks so much for sharing!

  3. bryan flake says:

    My air conditioner has broken down and I am not too sure why. All I know is that my house smells like dust and dirt. When cleaning the evaporator coil, I am worried about scrubbing it too hard and damaging it. Is this coil similar in idea to a heating element of an oven? The last thing I want to do is scrub it too hard and break the coil.

  4. Rachelle Reeves says:

    I just bought a new air conditioning unit, so I want to take good care of it so it lasts a long time. I’m not sure where the condensate drain, air filter, and evaporator coil are. Is there a diagram of the machine I could find to figure out what is what?

  5. Steve Holt says:

    Usually, I try to do things like change the air filter and clean the condenser unit to maintain my air conditioner. For some reason, my A/C still has been acting up this summer, so I need to get to the bottom of what I’m not doing to keep cool in my house this summer. After reading your article, I now see that i haven’t been cleaning my evaporator coil, and that must be one reason why my A/C hasn’t been working lately. Since keeping it clean can improve my air conditioner’s efficiency and freshen the air in my home, I should get to work on cleaning it right away. Thanks for the tips!

  6. DoloresB says:

    We change the air filter at my house a lot. My brother has a really hard time with breathing and allergies. So we use the a/c unit kind of as a filter. It means we do have to buy a fancy air filter and clean it regularly, but that’s better than having him struggle with breathing.

  7. Kyle Ross says:

    These are some great tips for AC maintenance, and I appreciate your advice to change the air filter. This is a simple thing to do, and is definitely worthwhile if it can improve the efficiency of your air conditioner. How frequently do you suggest changing out air filters?

  8. Natalie Darcy says:

    I always feel so inadequate when I try to do anything with my air conditioner. It seems like such a complex machine and I have a very unclear idea of how I should be taking care of it. This article was actually really helpful to me, it makes so much more sense to me after your thorough explanation. Thank you for the detailed instructions, I will be applying your tips soon!

  9. Betty Johnson says:

    To be honest, we have never tried cleaning the evaporator coil on our AC. I bet it could really use it. Well, better late than never, right? It’s worth it if we can make it more efficient.

  10. Brandon Roberts says:

    I really appreciate you talking about this, and letting me know of some things I can to to help keep my A/C running properly. I have been having some trouble with my A/C unit lately, and I have no idea what is going on with it. I think that when I try these 5 steps, that I’ll be able to figure out what is wrong.

  11. Casey Jones says:

    Thanks James for all the advice on air conditioning maintenance tips. Hopefully I can keep mine running strong by following your advice. It has been a while since I replaced the filter, so I will do that asap.

  12. Cohen Jacobson says:

    Hey I really appreciate these tips. Do you know of a video clip online that might explain this in a little more detail? I’m a bit more of a visual learner and its sort of my preferred method. In general though I’ll keep these tips in mind for when I’m out inspecting my AC unit. Oh! and do you have any tips for heaters and furnace maintenance? Thanks for the great post!

  13. Jessy Shaw says:

    My husband usually does a pretty good job when it comes to the maintenance of our air conditioning unit but is has started to have a lot of issues. Luckily, the summer months are over and the outdoor temperatures are cooling off so we don’t have to worry about it too much. I would like to make the necessary repair before next summer. I will pass these tips on to my husband to see if we can troubleshoot the issue.

  14. Connor Adams says:

    I like how you said, “The most important step is to clean the condenser coils, which comprise the unit’s grill-like exterior.” I have had a few air conditioning units that have stopped working just because the condenser coils were dirty. It was so frustrating to hire a repair man just to come out and clean something that I could have cleaned in five minutes. Thanks for posting!

  15. Eliza Cranston says:

    These are some great tips for keeping your air conditioner in good condition. I’m looking to avoid repair fees and to safe energy by making my air conditioner as efficient as possible. I’ve done most of these things but I wasn’t aware of the need to clean the evaporator coil so I’ll do that before it gets hot again!

  16. jamesrod214 says:

    I feel like my air conditioning unit could use some maintenance, but I don’t want to call HVAC maintenance services. So, thanks for the great tips. I think I could do most of those without too much hassle. One thing I need to do is clean the evaporator coil.

  17. Logan Murphy says:

    I need to do a better job at changing the air filter to our air conditioning unit. We want to safe some money on our AC bill and I think this will help. I like the idea of getting a cleaner air flow in our home. How often would you suggest changing it? Thanks for the good tips. We will definitely have to do a better job with maintaining our HVAC.

  18. I really appreciated all of the insight you give to properly maintain your air conditioning unit yourself. Specifically, you talk about how changing the air filter is a basic step that will help ensure that the air flow is clean and efficient throughout the home. Overall, I think that regularly checking the filter and replacing it will help you to not only keep your air conditioner efficient, but in quality condition, too. Thank you for sharing!

  19. Breck Lewis says:

    I had no idea that you actually had to clean the inside of the a/c unit. I guess it makes sense why you want your coils to be clean so they can be as efficient as possible. My a/c has been acting up and I went out the other day to try to fix it, but I think I actually made it worse. I called the professional to come out and fix it and it started working again. Thanks for posting this article because it helped me realize the importance of maintenance.

  20. bryan flake says:

    I’d be afraid to clean something like the evaporator coil. If I did that, would there be a high likelihood of wrecking the coil? Hopefully, I am able to apply some elbow grease without cracking the coil.

  21. Zach Potter says:

    Awesome article on air conditioning and servicing! After our AC gave out a few weeks ago I have been trying to do some research on my own before calling in a professional. I know that if I had taken better preventative care for it, it would have likely been fine (especially if I had done number 2 and 4). Thank you for sharing this article and everyone for commenting as sometimes that is the best thing to read to find information.

  22. Emily says:

    My husband and and I just moved into our first house. We want to do everything we can to make sure that the things in our house are being properly maintained. The tip about being proactive about system testing when it comes to air conditioners seems like a good idea. We will have to keep that in mind!

  23. Michael Lee says:

    I agree with the author on the importance of actually testing your system in order to be proactive on confirming any maintenance needed. I always procrastinate, and so I have been making an effort to do these types of things. Does anybody know whether electric or gas heating is cheaper and more efficient by the way?

  24. Nora Moore says:

    Are these maintenance jobs really easy to do yourself. It never would have occurred to me to clean the evaporator coil myself. It sounds easy enough, though. Keeping your AC in top condition is really important, so I should probably check these things out.

  25. Jordan Jorgenson says:

    Thanks for your tip about the air filter. I thought that the higher the efficiency rating on the filter the better it would be for my system. How do I find out what air filters are rated for my air conditioning system?

  26. Travis Thompson says:

    Keeping up on the maintenance required by air conditioners can save you a fortune in repairman fees! I’m glad you included the condenser and the drain in the list of things to clean. Many a clogged air conditioner has died from back-up, and usually this happens in areas that require an air conditioning system even just to live!

  27. Wendy Cartright says:

    Thank you for sharing these helpful HVAC maintenance tips. I thought your tip number five was very smart. Checking to make sure your system works properly in the spring time can save you a lot of time and frustration.

  28. Jason Strong says:

    My mom and dad are in need of a new AC unit asap. The problem they are running into is not knowing what to look for in a new AC system. This has some great points that I think can help them figure this out.

  29. Deanna Jones says:

    I thought that you made a great point about how system testing my HVAC can help improve how my air conditioner runs. Usually, I’ll repair my air conditioner during the summer when I need it to work rather than fix it before it’s hot out. Testing my system in the spring is exactly what I need to do from now on to detect any changes that need to be made so that it will work in the summer. That would be a welcome change so that I can finally feel cool in my home from the moment that I need to turn it on to the moment it needs to be turned off. Thanks for the tips!

  30. Bennett Fischer says:

    I noticed you said that it’s important to clean the evaporator coil to make sure my AC runs right. How often do I need to clean it? And do I need to have someone come and help me clean it, or am I going to be able to do it on my own? I’m not the move “hands-on” kind of guy, so I’m really worried about this.

  31. James Bergman says:

    I think the only thing that I do on a regular basis, to maintain my air conditioner, is to change the filter. I’m a little scared that if I try cleaning the condenser or evaporator coils I will damage my unit. I’m probably over thinking this though. I do think I can suck the sludge out of the drain pipe though. Is there any other way of flushing the condensate drain?

  32. Dee Francis says:

    It’s helpful to know how being proactive with my system testing can benefit my A/C. You’re right about how it’s best not to wait until the summer to fix my air conditioner. Testing my unit throughout the year will help me know about anything that needs to be repaired so that I can have a working system throughout the summer. Thanks for the tips!

  33. Jeff Curtis says:

    Thanks for these tips on how to clean up my air conditioner. I have never actually cleaned out the evaporator coil, I will have to try it out and see if the system runs better. I am pretty good about changing the air filter, but I have no idea when the last time my homes air conditioner was inspected. I will have to get that done, thanks!

  34. Kyler Brown says:

    Now that the weather has been warming up, I need to make sure my AC unit is up to date before I turn it back on. I’m glad that I read this because I didn’t realize that cleaning the evaporator coil will improve the efficiency and freshen the air inside your home better. I’ll definitely take the time to do that so thanks for helping me out with this stuff!

  35. Nash Rich says:

    I would be the guy who turns on his A/C as late into the summer as possible and find it doesn’t work. So I thought the tip on testing it in the spring was good. I guess I should stop putting things off too late!

  36. Vicky Durrant says:

    I recently had my air conditioning unit repaired, and I want to make sure that it stays working for a long time to come! I really liked your air conditioning maintenance tips, especially what you mentioned about regularly cleaning the condenser unit. I’ve never done this in the past, but I’ll make sure that it becomes a regular thing in my home! Thank you for the advice!

  37. Richard says:

    Excellent post! I remember when our A/C got a problem it’s not getting cold anymore. My husband called his friend who fixing this equipment. Good thing there is no serious problem, it just needs to be clean. He teach my husband how to do it for the next time he can do it himself. I show this article to him it will help us to keep our A/C well-maintained.

  38. John Carston says:

    I need to fix our broken air conditioner so this post has been very helpful. I haven’t tried cleaning the condenser unit or the condenser drain so I’ll have to do that. I’ll go through the other steps you provided as well and if I don’t find a solution I’ll try a repair service. Thanks for the helpful air conditioning tips.

  39. Aria Wellington says:

    I have never heard of a high-efficiency air filter. I will have to do some research on those because I don’t really know what they do! We want to get some maintenance done on our HVAC system so we will have to call in a specialist and as him about these types of filters. I wonder if they would be compatible with our system.

  40. Judy Wilson says:

    Being proactive about system testing my air conditioner seems like a great tip. Doing that would help me find out if there’s anything wrong with my A/C. You’re right about how I should do this now while it’s still fairly cool outside, so I’ll make sure to have my air conditioner inspected before summer.

  41. Faylinn says:

    I just moved into my first apartment and have never had to take care of an AC before. That is why I really appreciate your advice about changing out my air filter so that the airflow is good. However, how often should I being changing the filter out?

  42. Jalu Sakti says:

    I haven’t ever experience this, but I have known friends who didn’t keep their filter clean, and because of that, the air barely got through and couldn’t keep their homes cool. I’m glad you talked about that point because it reminded me of those friends and their experiences. I am actually just looking at getting an AC unit put in to my new home, and this will be really important for me to remember. I’m just hoping there is a good AC company near me in case I need help!

  43. Kate Hansen says:

    Last summer our air conditioner quit on us in the middle of a heat wave. I don’t want to put my family through that again, so I think making sure we get maintenance done to our unit will help prevent that from happening. I like how you mention that you should be proactive about system testing because I’m sure a professional knows exactly what to look for when testing your system.

  44. Johnny McCarron says:

    I really like your advice to change the air filter regularly. It seems to me that a lot of people don’t understand the importance of having a good, clean air conditioner. Not only does it help your air conditioner last longer, but it also helps your air quality get better. Do you have any other tips about finding a good air conditioning system?

  45. Yilliang Peng says:

    I appreciate the information listed here about how to better maintain your air conditioning. My wife and I love our air conditioning and would hate to see it break down. We honestly have no idea how to maintain it so we are grateful for the tip to clean the drain up every so often. Thanks again!

  46. Luke Smith says:

    Thanks for the tips to clean the condenser unit on an AC unit to keep it clear of debris. It makes a lot of sense as a maintenance item since it’s typically outside of the house. I bet that having a professional inspection done at least once a year would be a good idea as well.

  47. Jake Beals says:

    Cleaning the condenser is a great idea. After recently purchasing a home I have a need to maintain my air conditioner. This weekend I was involved in peoria heating and cooling. lol Thanks so much!

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