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7 Ways to Keep Your Central Air Conditioning Unit in Shape

I have a love-hate relationship with our AC unit: I love it when it's hot out, but I hate it when it quits! Here's how I keep it running.

How to keep your central air conditioner in good condition!

How to keep your central air conditioner in good condition!

How to Keep Your Central Air Conditioner Running Efficiently

To be honest, I have a love-hate relationship with our central air conditioning unit. That is to say, I love the central air conditioner when it's hot outside and fills the house with refreshing, cool air, but hate it when it's hot outside and quits working.

As a homeowner for more than 20 years, I have had a few repairs done on the central air conditioner that we rely on so heavily during the summer months. This much I know without a doubt: It's far cheaper to maintain this appliance on a regular basis than it is to repair or replace it. In fact, Carrier, a leading manufacturer of air conditioners, states:

Proper air conditioning maintenance can help your unit last decades. On the flip-side, a neglected air conditioner loses roughly 5% of its efficiency each year that it operates without upkeep.

Fortunately, there are some very simple things that any homeowner can do to keep their A/C unit running efficiently and perhaps even less often throughout the warm months.

7 Air Conditioner Maintenance Tips

  1. Keep Plants Cut Back Around Unit
  2. Wash Pollen and Other Debris Off Condenser Unit
  3. Do Not Close Any Registers Completely
  4. Change the Filter Regularly
  5. Set Temperatures in a Programmable Thermostat
  6. Keep the Sun Out
  7. Get a Professional Inspection and Cleaning Done Annually

1. Keep Plants Cut Back Around Unit

Let's face it: Outdoor air conditioning condensers are ugly and it seems like homeowners will do their best to hide them from sight. Plants, fences, and trellises are popular ways to hide the ugly A/C units.

But since they need an adequate amount of airflow around all sides in order to perform at peak efficiency, experts recommend that landscaping and other objects be placed about three feet away from the unit itself.

Cleaning up leaves and other debris on a regular basis, as well as trimming or cutting back bushes, trees, and other plants all help increase the air that your unit needs to draw into its system.

2. Wash Pollen and Other Debris Off Condenser Unit

If your outdoor air condenser unit is in an unnoticeable location, it's very easy to forget about cleaning it regularly. But you don't want to neglect this very easy chore. The condenser pulls in air, and when it does, pollen and other debris often cling to its exterior. This will restrict airflow and cause a decrease in cooling efficiency and perhaps even cause the unit to overheat.

The Solution

Pull out your garden hose, and with a hard stream of water, working top to bottom, hose off each side of the condenser.

Pollen like cottonwood can easily accumulate on the A/C, blocking airflow.

Pollen like cottonwood can easily accumulate on the A/C, blocking airflow.

3. Do Not Close Any Registers Completely

With a two-story house, the upper level is often warmer than the lower level even with the central air running. This is the case with our home, and knowing that hot air rises and cool air falls, I figured I could easily balance the air temperature by adjusting the register (air vent) openings.

The Mistake

It is true that closing some registers on the cooler lower level forces more air out of the registers upstairs. The cooler air then works its way downstairs and the air temperature becomes more even throughout the house. However, by doing this the air conditioning unit may completely shut off!

In fact, when I totally closed some lower-level registers, the coils in the unit froze and the A/C quit functioning. Luckily, by shutting off the entire cooling system and giving the coils time to thaw, the A/C was up and running again within a few hours.

The Lesson

Do not completely close registers. To balance the air temperature, registers can be slightly closed but do not close them completely. (It took me two times to learn this lesson.) Additionally, make sure supply vents are not blocked.

4. Change the Filter Regularly

Maintaining a central air conditioning unit is all about maintaining airflow. That is why it is important to regularly change the air filter on the system.

Filter packages usually state a recommended schedule for replacement (i.e., every 90 days or so), but it really depends more on how much the unit is running and how dirty the air is.

During hot months, it may be beneficial to change the air filter more frequently. The process is often as simple as sliding the old filter out and sliding in the new one.

According to Trane air conditioner manufacturers,

...regular cleaning/changing of your filter will ensure the best filtration, increase the life of your machine, and give you peace of mind that you’re breathing easier.

Remove dirty filters regularly to ensure proper airflow to air conditioner.

Remove dirty filters regularly to ensure proper airflow to air conditioner.

5. Set Temperatures in a Programmable Thermostat

It stands to reason that the less the air conditioner is actually in use, the less wear and tear it endures. For anyone with a programmable thermostat, setting the temperature by day and time is a good way to reduce the unit's overall usage.

For example, we set our temperature higher during the daytime and colder during the hours when we sleep. It's far more efficient to program in desired temperatures than it is to shut the unit off completely and then turn it on after a day of work.

6. Keep the Sun Out

Another excellent way to keep the air conditioner from needing to run as often is to block the sun during the hottest part of the day. During the hours when the sun shines in the most, blinds or drapes should be closed.

This way, the home's interior temperature will not rise as much. Additionally, consider planting trees or installing awnings to diffuse some of the sunlight.

Filter out the sun with blinds, drapes, and even shrubs and trees.

Filter out the sun with blinds, drapes, and even shrubs and trees.

7. Get a Professional Inspection and Cleaning Done Annually

Before each cooling season, it is a great idea to get a regular maintenance check and cleaning done on the unit by an HVAC professional. Service professionals usually inspect the control box, coils, fan motor and blades, and compressor and tubing, among other things. Additionally, refrigerant levels are inspected and adjusted if necessary, and the unit cleaned.

As the old saying goes, an ounce of prevention is worth a pound of cure. If you've ever had your central air conditioner quit working on the hottest day of the year, you fully understand that preventative A/C maintenance is definitely preferable to repairing or replacing it due to neglect.

This article is accurate and true to the best of the author’s knowledge. Content is for informational or entertainment purposes only and does not substitute for personal counsel or professional advice in business, financial, legal, or technical matters.


David on July 31, 2019:

George, not an AC guy but I had the same problem. You have a leak somewhere and it's not going to get better. I got a few more years out of it before I replaced it. What I can tell you is my new one performs much better and glad I updated it. Take time now to research models and save for a new one.

George on July 10, 2019:

My pipes inside and outside frost up. Repair man added 1lb freon and ut was fine. Should I be looking at new unit soon?

Steve on May 23, 2015:

Today my wife and I put down fill dirt on the north side of house and mulch on top to absorb rain water. We put dirt and mulch right up to the pad the air conditioner condenser sits on, the system still has airflow on all sides. Does anyone know if this is ok?

Amelia Brose from Carlton, Victoria, Australia on January 28, 2014:

Thanks for the great content! This information is very accurate and informative

Vespa Woolf from Peru, South America on April 21, 2013:

Wow, I don't know how I missed this one. Congrats on the HOTD you won for it. This is certainly chock full of useful information. A little maintenance sure does go a long way, even on air conditioning units.

Kristin Trapp (author) from Illinois on December 14, 2012:

Dolores - Hosing the pollen off your AC unit is a really simple thing to do to help keep it running smoothly and efficiently. You will probably want to do this a few times during the spring when the pollen is probably at its peak.

Dolores Monet from East Coast, United States on December 14, 2012:

Thanks for the simple tips to keep that AC in good working order. The pollen around here can be heavy at times, and I just don't think of hosing it off. Will do next spring!

Michael Luckado from Hawaii on October 14, 2012:

Nice hub. I would also add...make sure the unit is level on the exterior of you home. Some of the new models are installed on brackets that attach to the foundation. However, the older ones need to be leveled. I walked by one that was out of level in my neighborhood the other day and it was making a horrible sound...not good.

furniturez from Washington on August 08, 2012:

Definitely important to keep the central air clean of debris and shrubs/plants surrounding it trimmed down to a reasonable level... I learned this the hard way!

Kristin Trapp (author) from Illinois on June 07, 2012:

Hi Howard. Well you sound more capable when it comes to actual air conditioner repairs than I ever will be. Check out cre8tor. He works in HVAC and has terrific hubs of this nature.

Howard S. from Dallas, Texas, and Asia on June 07, 2012:

A couple of weeks ago I noticed a problem with the drains from my indoor cooling coil pan. It's happened before and I fixed it, but I either don't remember how or it's not working. The secondary is only supposed to drain when the primary clogs. They're both dripping--and I've tried blowing out the primary. I guess I'll have to open the cooling coil unit itself and study it from that end. It probably needs cleaning anyway.

(BTW, I denied a similar spam link from @Mike on my hub.)

abdul ghaffar on June 07, 2012:

good information about air conditioning please add current problems and remedy thanks abdul ghaffar from faisalabad pakistan

Kristin Trapp (author) from Illinois on June 05, 2012:

Thanks RTalloni. I do hope this is helpful to a lot of people.

RTalloni on June 05, 2012:

Congrats on your Hub of the Day award for a hub that will be helpful to many people!

Kristin Trapp (author) from Illinois on June 05, 2012:

Thanks Skyler. This was in response to a weekly topic inspiration which happened to coincide with some much needed A/C maintenance that I needed to do. I still need to edge and mulch around that condenser unit - such is the life of a homeowner. This certainly is one appliance you don't want to go on the fritz in your neck of the woods around Dallas. I lived there for a few years and remember all too well how incredibly hot it gets there day after day.

skylergreene on June 05, 2012:

So not surprised that you got Hub of the Day again. Hats off to you -- this really is an awesome and useful Hub. I change the filters regularly and wash the condenser off every so often, but I didn't know it was beneficial to trim plants.

Kristin Trapp (author) from Illinois on June 05, 2012:

Ardie - I know exactly what you mean. My dad fixed everything, appliances, cars,televisions - heck, he even built the house. I cannot recall ever having one single repairman or contractor out to the house when I was a kid. So it is hard to pay when you know that with some know-how the job can be done for free labor. That's why it's nice to try to avoid costly repairs with a little bit of maintenance.

Sondra from Neverland on June 05, 2012:

This is JUST what I need right now. The hot weather is right around the corner for us. I dislike spending a ton of money for someone to maintain my central AC when I've watched my dad do it to his own for free since I was small. Thanks for the tips!!

Kristin Trapp (author) from Illinois on June 05, 2012:

Thanks urmilashukla23. How nice of you to read, vote, and take the time to let me know that these A/C tips are helpful.

Kristin Trapp (author) from Illinois on June 05, 2012:

Rebecca - I'm glad to know these air conditioner maintenance tips were helpful. Thanks for letting me know.

Urmila from Rancho Cucamonga,CA, USA on June 05, 2012:

Great central air maintenance tips. Helpful and voted up.

Congratulations on Hub of the day award!

Rebecca Mealey from Northeastern Georgia, USA on June 05, 2012:

Great Hub to keep up to date on cooling our homes efficiently this Summer. It is extremely helpful! Congratulations!

Kristin Trapp (author) from Illinois on June 05, 2012:

sammimills - I'm glad I could help and thanks so much.

Kristin Trapp (author) from Illinois on June 05, 2012:

jpcmc - And better output is a money-saver all around.

sammimills from California, USA on June 05, 2012:

Very informative and useful hub! I learned and discovered a lot. Congrats on being LOTD! Deserving.

JP Carlos from Quezon CIty, Phlippines on June 05, 2012:

Proper maintenance will definitely give you better output - plus less trouble in the future. Simple steps make it easy!

Kristin Trapp (author) from Illinois on June 05, 2012:

coffeegginmyrice - Thank you and I'm glad you liked my dog; I have to include her every now and then since she is my ever-present writing partner.

Marites Mabugat-Simbajon from Toronto, Ontario on June 05, 2012:

Wonderful tips to keep in mind. Congratulations, ktrapp! I love the dog by the window, nice photo!

Kristin Trapp (author) from Illinois on June 05, 2012:

Kristine - It's perfectly fine to hose off the outside of the unit. After all, it gets wet in the rain, but you probably shouldn't spray the inside. Perhaps leave that cleaning to professionals if it's even necessary.

Kristine Manley from Atlanta, GA on June 05, 2012:

What useful information. I did not know that I could hose down the condenser unit and I will be doing this. Thanks.

Kristin Trapp (author) from Illinois on June 05, 2012:

I'm glad this is handy information for you, TheMagician. Thanks for letting me know.

Kay B from Tampa, FL on June 05, 2012:

Wow, tons of great information that I never knew about! This will definitely come in handy. Thanks! Voted up and useful :)

Kristin Trapp (author) from Illinois on June 05, 2012:

Thanks Steph. I'm doing everything in my power to extend the life of my air conditioner as I dread the cost of a new one. I believe our unit is about 14 years old now. I bet you might know a thing or two about "greener" air conditioners - is there such a thing?

Kristin Trapp (author) from Illinois on June 05, 2012:

joaniebaby - Our filter for our furnace and air conditioner are one and the same which is probably the case with yours since the two systems would share the same duct work throughout the house. So you probably should change it soon if you haven't in awhile. I'm glad this was info. you could use.

Stephanie Marshall from Bend, Oregon on June 05, 2012:

Great hub, Kristin! Very simple, easy to follow steps to keep the A/C running throughout the summer, without having to call maintenance or - heaven forbid - buy a new central air conditioning unit. Congratulations on HOTD! Best, Steph

Kristin Trapp (author) from Illinois on June 05, 2012:

That's funny Victoria Lynn. Thanks for stopping by this hub again.

Kristin Trapp (author) from Illinois on June 05, 2012:

VirginiaLynne - I really appreciate the added information learned from your HVAC copywriting experience. Due to the cost, I have always dreaded when the day comes to replace the entire A/C unit, but you make an excellent point about electricity usage on older units.

Kristin Trapp (author) from Illinois on June 05, 2012:

kthix10 - While I'm not an HVAC professional (see cre8tor who commented a few above this - he has incredibly helpful hubs since he's in the biz) you might want to open the supply vents and with the air conditioner running see if you feel any air flow. Where you have return vents (the ones that pull the warm air out of the room in the summer and cold in the winter) hold a piece of paper up to it when the A/C is on and see if it "sticks" to it from the draw of air. If those things happen then those rooms are part of the system. But I would have a professional do a quick inspection if I were you.

Kristin Trapp (author) from Illinois on June 05, 2012:

Thanks happyboomernurse. The pollen can get really bad if left unchecked. I didn't put a photo of the back side of the condenser up, but it was completely covered in pollen from just a couple months of spring. It's funny, but when I've watered neighbors' outdoor plants while they are on vacation, I have also hosed off a few dirty A/C units; clearly they had no idea they should do this - no charge of course :) Thanks for the nice comment and votes.

joaniebaby on June 05, 2012:

Great Hub. I didn't even realize an A/C unit had a filter. We always clean our furnace filter. Is this the one the A/C uses, or is there another one in the A/C unit itself? Thanks for the info.

Victoria Lynn from Arkansas, USA on June 05, 2012:

You are the Hub of the Day Queen, ktrapp! Congratulations, once again!

Virginia Kearney from United States on June 05, 2012:

Good information. I do copywriting for a number of HVAC companies and have written on this subject before, but not for Hubpages. It is also important to look into the type of MERV filter you use because some need to be cleaned more often and reduce efficiency. Another thing to consider is that sometimes replacement is cost effective if your unit is older (10 yrs or so) because the older units used so much more electricity. Congrats on Hub of the Day!

kthix10 from IL on June 05, 2012:

Thanks for the tips - some of them we already did but I really do need to clean the filter. We have duct work in the floors and ceiling of our one level house and I do have some blocked because I am not sure if they are part of the system or not - I really need to have a profession tell me about it

Gail Sobotkin from South Carolina on June 05, 2012:

Great tips to keep central air conditioners running and lasting longer through regular maintenance. Most I knew and already do but some I didn't, like the importance of hosing off the pollen and debris around the unit.

Congrats on earning Hub of the Day for this excellent article.

Voted up, useful and interesting.

Kristin Trapp (author) from Illinois on June 05, 2012:

Thanks Kelley. It's so easy to forget to do some of these tasks (out of sight, out of mind), so I'm glad you found this useful.

kelleyward on June 05, 2012:

Awesome Hub Ktrapp! Thanks for the useful information on this subject! Congrats on winning HOTD!!! Take care, Kelley

Kristin Trapp (author) from Illinois on June 05, 2012:

Cre8tor - Thanks so much. You've got the most helpful hubs on this topic too.

myownlife - Glad you found each of the tips to be useful.

ytsenoh - Nice to know you found this to be an excellent guide. I appreciate you letting me know that.

Cathy from Louisiana, Idaho, Kauai, Nebraska, South Dakota, Missouri on June 05, 2012:

Excellent hub! Great step by step instruction guide in how to care for your AC unit. Thanks.

myownlife from london on June 05, 2012:

its really a useful tips of each and every one. Great job

Dan Reed on June 05, 2012:

Congrats on HOTD ktrapp!

Kristin Trapp (author) from Illinois on June 04, 2012:

How wonderful for you, moonlake, that your son has a heating and air conditioner business. I don't think you're crazy to have central A/C; when it's hot it's nice to be able to cool off indoors. Thanks for commenting and voting.

moonlake from America on June 04, 2012:

Lots of good information. I love our central air. People hearsay it's crazy to have it but I don't think so, we have never been sorry we put it in. If we need it fixed we call our son. He's a has a heating and air business. Voted up on your hub.

Kristin Trapp (author) from Illinois on June 04, 2012:

Thanks Simone. A lot of these tips fall under the category of "live and learn." Air conditioner and furnace repairs can be pretty costly, and being without either isn't too pleasant either.

Simone Haruko Smith from San Francisco on June 04, 2012:

What a thorough, useful, practical, clearly-written guide! This is SO helpful! I love the original photos, and really appreciate the tips. Most of those would not have been at ALL obvious to me, so should I ever find myself living in a house with central air conditioning, you'll have saved me a lot of trouble!

Kristin Trapp (author) from Illinois on June 03, 2012:

Thanks catgypsy. You should definitely clean up around your A/C.

catgypsy from the South on June 02, 2012:

Excellent hub ktrapp. I do all of these things, but it reminded me that I need to go wash it off and trim some weeds away from it! Thanks!

Kristin Trapp (author) from Illinois on June 02, 2012:

I guess it really depends more or less on the percentage that is closed throughout the house. Heating and air conditioning systems need that air flow to operate efficiently and to extend the longevity of either the furnace or the air conditioner. So you have to be careful when closing the supply registers. I have seen where some professionals say it's OK to close 20% of the airflow off and others say not to do it at all since there are risks involved.

Victoria Lynn from Arkansas, USA on June 02, 2012:

ktrapp, In the rooms I don't use a lot, I just opened them up a little bit to let some air flow through. Think that's okay?

Kristin Trapp (author) from Illinois on June 02, 2012:

Thanks for letting me know Victoria. If you find the air temp is too uneven from room-to-room or perhaps from downstairs to upstairs you can balance the registers by closing some a little bit. There's good information out there on how to balance registers (easy to do).

Kristin Trapp (author) from Illinois on June 02, 2012:

Thanks randomcreative. All of these suggestions are quick and easy, so it makes sense for homeowners to do them and extend the life of their air conditioners.

Victoria Lynn from Arkansas, USA on June 02, 2012:

I opened up my closed vents, today, if not all the way open! thanks for the valuable information!

Rose Clearfield from Milwaukee, Wisconsin on June 02, 2012:

Great topic for a hub! I will definitely take some of these suggestions into consideration!

Kristin Trapp (author) from Illinois on June 02, 2012:

Oh no mts1098. I think you need to leave your man cave (that is where you said you lived in your profile, right?) and head out to the store to get some filters. Changing them every two years is way too long. It should be closer to every 90 days. (Maybe you meant to write two months.) Anyway, it's real important to trim back plants around the air conditioner too - anything to improve airflow is what's needed.

mts1098 on June 02, 2012:

Glad I read this as the summer season is beginning to heat up...I change the filters every two years but I think I have to go and trim the surroundings...thanks and cheers...

Kristin Trapp (author) from Illinois on June 02, 2012:

MarleneB - Glad to have been able to help.

Marlene Bertrand from USA on June 02, 2012:

This is very helpful information. My husband does all the maintenance around the house; I never really paid much attention to what he does. But, I have learned after reading your hub, I need to open up a few registers.

Kristin Trapp (author) from Illinois on June 01, 2012:

Thanks Victoria. Not only can closed registers cause the coils to freeze, so can low freon. Freon levels is one thing that is checked in an annual maintenance and must be done by a professional. Obviously the cost of an annual inspection varies, but it is usually in the neighborhood of $100. Some companies offer packages to come out once before the cooling season and once before the heating season at a discounted price. But when it comes to a central air conditioner, small repairs can prevent costlier problems from occurring. It's definitely worth it in the long run.

Victoria Lynn from Arkansas, USA on June 01, 2012:

Such a useful hub! I need to open up some of those registers a bit; some are completely closed off. Great tips. I don't know the last time my unit was inspected. Is that expensive? But worth it, I'm sure. You write such informative, helpful hubs. Thanks!