Filters are VERY important. Dirty filters responsible for a ridiculously high volume of totally avoidable service calls. They restrict airflow and cause unit damage if left clogged long enough. So, please don’t ignore your filters. They should be changed at least once per year, twice if the system runs year-round, and more if you’re using pleated filters. The rule of thumb is, change it when it’s dirty. Filters are important, but filters are only half the battle.

This is my cat Mulligan. He was mildly offended at the dirty filter comparison, but relented when he learned that it was in the interest of educating customers. If your filter looks like him (grey and/or fuzzy), it’s time to change it!
Though there are some basic maintenance tasks that can be done on a DIY basis, like filter changes, or if done carefully, coil cleaning, it’s a good idea to use a professional HVAC technician at least once before each season (heating and cooling) to fully test unit operations. Your heating, cooling and refrigeration equipment is complex. Even more complex today than at any time in the past, and you can bet that in the future, they will be more complex even still! It’s entirely possible that someday your HVACR unit will become self aware and try to take over your building a la The Terminator. (LOL! Not really. I mean, probably not…)
Because of their complexity, a true maintenance plan needs to be about more than just filters and belts. Just to cover the basics, it needs airflow, proper refrigerant charge, correct electrical voltage & current, fully-functional safety components and properly programmed controllers, etc. If any or all of these items are not up to par, you will not get the performance or the longevity you want out of your equipment, no matter how many times you change the filters. In addition to the basics, it should also take into account the manufacturer’s maintenance recommendations for your specific unit, which is in the Installation and Operations Manual (IOM). (Fear not. Reading the manual is not a sign of ignorance. In today’s HVACR world, it’s an indication that the tech really knows what he’s doing, has good attention to detail and is a true professional.)
Not all “HVACR professionals” treat maintenance the same way. If an HVACR contractor is trying to get in the door by selling you a “cheap” maintenance agreement, they’re probably not doing a thorough job. For example, to properly test an AC unit, it should run for at least 20 minutes. Any less and you’re not getting accurate refrigerant pressure readings, which you need to test basic AC operation. So before you blindly take the low bid, make sure you check the labor hours of the maintenance agreement. If it’s less than one hour per AC unit (or less than two hours if they included coil cleaning), you’re probably not getting a proper PM. Because if they’re not checking basic AC operation, what else aren’t they checking?
Utilizing a professional to check cooling equipment can protect your HVAC investment (because we know these units aren’t cheap!) and prevent things like damaging water leaks, or embarrassingly sweaty summer meetings, but an experienced eye becomes even more important during the heating season, when a technician can identify and correct dangerous life safety issues that could result in fire, carbon monoxide poisoning, explosion, The Terminator, etc. Check out more benefits of maintenance agreements on our webpage.
Paige Smith says
I think your analogy for cleaning the filter is so funny. I agree that if your filter looks like a big gray cat, then it is time to change it. Thanks for the humorous reminder.
Karen Lamy DeSousa says
Thanks Paige! That is actually my cat Mulligan in the photo. I was working from home one day and heard a meow. When I looked over I saw him hamming it up, so I snapped the pic. I’ve seen a few furry grey filters in my time. But none so cuddly as this guy.
Kaitlyn says
I’m a little ashamed to admit that my filter looked like Mulligan a few months ago. But I’ve fixed it!
Karen Lamy DeSousa, Advance Air & Heat says
LOL! It’s a cute look for a cat, less so for a filter. But kudos to you for fixing the problem!
Kaitlyn says
Thanks! Tell Mulligan he’s been a real inspiration for projects of mine!
Karen Lamy DeSousa, Advance Air & Heat says
I certainly will! He’ll be so pleased. 🙂
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Patti Osterberg says
I’m definitely guilty of just doing an occasional filter change and ignoring other HVAC maintenance. I agree that I should also have a maintenance plan for the airflow and electrical work to keep everything efficient and safe. I’ll keep in mind that you should run the AC for at least 20 minutes to get an idea of if it’s working right. I’ll make sure I find a heating contractor that can do a thorough inspection of my HVAC system!
Jeffrey Goodman says
I don’t know much about heaters. If my filter looks like a grey cat I will replace it. I will go check the air filter to see if it is in need of replacement. Thanks for the advice!
Lillian Schaeffer says
This is some great information, and I appreciate your point that hiring a professional to maintain your HVAC unit is protecting your investment. I was looking at this as an added expense, but it really is beneficial to protect the system you spent so much money installing. From now on, I’ll definitely have a professional regularly do maintenance on my HVAC system so it stays in good repair. Thanks for the great post!
Jason Strong says
My wife and I moved into a home that has an HVAC. We have never used an HVAC before, so we are trying to get an idea of how it works and how properly take care of it. This helped us see the importance of not only changing the filters, but in keeping the coils cleaned and other maintenance tips as well. Hopefully we can do a good job at taking care of this.
Hailey Renee says
I would agree that bringing in a professional HVAC technician is a good idea before you start using your heating and cooling system. I am glad to know that HVAC technicians pay close attention to detail to ensure their job is done correctly. That is interesting that having a periodic check on your HVAC system can help protect your system.
Jen Pack says
My husband and I have been very careful about changing the filter on our HVAC system but I didn’t realize there was so much more to proper maintenance. It is interesting how you point out that coil cleanings and other maintenance processes need to be done by a professional to make sure that it is done correctly. I imagine that they can also find problems and dangers that the untrained eye won’t see. I will be sure to keep this in mind, thanks for sharing this!
Tobias Armstrong says
I had no idea that so many things go into HVAC maintenance. I’d heard of belts and filters, of course, but the airflow, refrigerant, electrical, all of that kind of stuff never even crossed my mind. It sounds like I need some help from the pros before I try and keep my own system up by myself. Thanks for sharing!
Hazel Adams says
I agree that if your filter looks like a large grey cat, then it is time to refill it. I did not realize that taking care of an HVAC system was so simple. I am excited to try these tips on my HVAC system.
Jeff Curtis says
Thanks for the helpful information on maintaining HVAC systems. I have usually been really good about replacing the filters, but like you said I am sure there are a lot other things to do to maintain it. I like your tip on having an HVAC professional do a maintenance check-up. Thanks for the help!
Nash Rich says
I love cats, so I liked the grey cat and filter analogy! I’ve never checked my filters since I’ve moved to my new place, which has been a while. I guess I should really check it out, especially with summer just around the corner. Thanks for the info!
برج خنک کننده says
Great post.
Thanks!
Kevin Huffman says
A couple more benefits of regular maintenance would be:
Lower utility bills/energy usage
Prolonged life of equipment
Reduce repair breakdowns
Piece of mind
Not to mention if you’re under a companies maintenance program you usually have these benefits:
Priority service over non-members
Discount on future repairs
No overtime charges
A good Maintenance plan normally pays for itself in future savings.
Judy Wilson says
It helps to know what more I can do to maintain my HVAC than by just changing the filter. Lately, I’ve just been replacing my air filter to take care of it. Now that I know to also make sure that it has enough refrigerant and properly programmed controllers, I’ll make sure that these are taken care of. Asking for help from an HVAC contractor would also help since they know more about how to repair and maintain it better than I do. Thanks for the tips!
Braden Bills says
I’ve been noticing some weird sounds and dust coming from my air conditioning. I didn’t realize how important it is to have my air conditioning checked regularly! I’ll make sure I do that from now on. Thanks for sharing!
Kenneth Gladman says
I would definitely recommend getting your system serviced at least annually. Your HVAC system uses a lot of energy and you want to make sure it is running efficiently. We are building our home this summer and are looking for a good contractor.
Kyler Brown says
I usually do change the filters on my AC unit, but I didn’t realize that there was more that I should be doing. Since summer is approaching, you make a pretty good case about the importance of using a professional HVAC technician at least once before each season. It makes sense that it would be better to keep the system well maintained than to suffer from a total breakdown. Thanks!
Marie Watson says
I like that you mention how a reputable HVAC professional can help protect your heating and cooling investment. It makes sense that having your system regularly inspected by a professional can ensure that your system continues to run efficiently. I would think that this will also ensure that your heating and cooling bills stay the same.
Rockford Johnson says
Reading this article has helped me to realize what proper HVAC maintenance really is. I really like how you explained that “Utilizing a professional to check cooling equipment can protect your HVAC investment.” I have never had problems with my HVAC unit before but it is good to know that having it checked and serviced regularly will help to extend the life your HVAC unit.
Simon Brooks says
Thanks for the fantastic advice, I had never heard about this whole needing to wait 20 minutes before properly testing the air conditioner thing. That’s something I’ll definitely have to remember to keep in mind the next time we need to have a new air conditioner installed at home. I’m also glad that you take the time to sort out what actually needs to be included in a maintenance plan because a lot of homeowners don’t realize how much work an HVAC system needs to keep itself maintained.
John Carston says
Reading through this article I realized I don’t have an HVAC maintenance plan in place. I’ll need to schedule a plan that covers airflow, refrigerant charge, safety components and properly programmed controllers. I may not have the time to do this myself so I may have to rely on a professional service but I”ll have to give this a try. Thanks for your post.
April Cook says
We turned our AC unit on the other day and noticed that it wasn’t cooling very efficiently. I didn’t realize there was more than filter changing that needed to be done, so I think its time to calla professional and have some maintenance done. How long does a maintenance check usually take? Thanks for this helpful information!
Karen Lamy DeSousa, Advance Air & Heat says
Great question April. There are a few factors involved in determining how long maintenance “should” take. The type and size of the unit are major factors. Units can range from small, simple residential style units which could take a couple of hours to thoroughly service, to massive commercial units with very advanced controls, which could take a couple of DAYS to service properly. Your HVAC equipment manual will have a recommended maintenance checklist procedure. Ask your contractor to quote your maintenance using that and you’ll get the right service for your particular unit’s needs. If you don’t have a contractor, reach out to two or three reputable ones for comparative quotes. Just make sure to check for insurance and licenses as part of your review process.
David Hawkins says
I had no idea that you should get your coils cleaned by a technician. I’ve never cleaned mine and I can tell that my heater is having a hard time lately. I’ll have to call a service and make sure everything is running how it should. Thanks for the great heater advice.
Marie Watson says
Karen, thanks for explaining the importance of HVAC maintenance. You make a good point about how it takes more than just regularly changing your filter to ensure that your system is running efficiently. I also like that you describe hiring a professional to inspect your system as “protecting your investment.” I would think that it is important to invest in regular maintenance and inspections to ensure that your system lasts as long as possible and keeps running efficiently as possible.
Charles Kemp says
I am glad that you mention that HVAC maintenance is more than just changing the filters. There are a lot of mechanical problems that can happen. You want to make sure that the mechanical contractors can fix the problem or at least check on it.
Brooke McAvoy says
I appreciate you going over the things that should be checked and maintained in a system like this. However, I know very little about these types of things and I am not sure I even know what some of the things that you described are. Do you have any tips for how I can figure it out on my own, or more information on the specifics of checking the essentials of an HVAC system?
Karen Lamy DeSousa, Advance Air & Heat says
Hi Brooke- The best place to look is the operations manual or owner’s manual for your specific HVAC system. If you don’t have one, don’t worry. Most can be found online with a simple Google search using the manufacturer and the model # of the unit. You can usually find the model number directly affixed to the unit, stamped onto a metal nameplate.
Theodore Winston says
I never knew that so much went into air conditioning maintenance. I guess that I really don’t know that much about my HVAC unit. I should probably have my landlord call the HVAC specialists so that they can come and do some air conditioning maintenance, and so that we can avoid any problems with our HVAC unit in the future. Thanks for the useful article!
climate control says
The example you set for us to understand the state of air filter is very good and impressive. In my opinion regular maintenance is very good and effective decrease the damage or fall cause of HVAC system. If you regularly main the HVAC system your air filter surly not look like a big grey Cat.
Kendall Everett says
Your suggestion to hiring a professional to check the HVAC unit out before each season was really helpful. If you are working in an office, it’s important that the unit is working as it should so the employees are comfortable. A professional would also be able to catch any potential issues and correct them.
Jack Mulligan says
I figured I would be fine by changing out my filters. I haven’t had any maintenance done in ages, so that’s something I should look into. Maybe I can schedule them to come periodically to check on things.
Karen Lamy DeSousa, Advance Air & Heat says
We generally recommend twice per year. Spring and Fall are best for our area (New England).
Jade Brunet says
I think that it is a good idea to keep up on HVAC maintenance to save stress and money. Thank you for informing me proper maintenance is more than just filters and belts. I also agree that it would be wise to consult a professional for advanced help.
Stefan Boyadjiev says
Great way of explaining why our air conditioner need a real maintenance plan. Similar to the way people that care for their health go on yearly check-up with a doctor. The HVAC unit is the most expensive part of the house that sometimes we take for granted , but it is time for us to understand that little care will go a long way.
Jeff Carbine says
I usually like to do things myself, but I have learned from past mistakes that I need to hire professionals to service my commercial refrigerators. There are so many things that need to be maintained, serviced, and monitored with commercial refrigerators. Pressure cleaning condenser coils are not things to forget and be messed around with. These are massive machines, and one really needs to know what she or he is doing in order to service it.
Jade Brunet says
Thank you for this article about proper HVAC maintenance. It is good to know that not all professionals treat heating and cooling system maintenance the same way. Something to consider would be to seek references to find a good service that can provide quality work in a set amount of time.
Georgia Boothe says
We’ve been making sure to get our filters changed, but it’s good to know that there is so much more to HVAC maintenance! I want to make sure we get the most out of new cool air/heat system, so we’ll get a contractor out to check to make sure the airflow, refrigerant charge, and everything else you mentioned are up to par!
Luke Smith says
I like your comment about how changing a dirty or old filter could prevent other forms of maintenance. I’m sure that for an average homeowner that means changing your air conditioner’s filter every month or two would prevent a call to a repairman, but in an industrial setting I imagine that could make an even bigger difference. If a filter that works properly extends the lifetime of a system, keeping your filter clean and changing it regularly could add up to really big savings.
Sarah Smith says
I recently got a new HVAC system, and I want to be sure that I take proper care of it. I had no idea that you need to be sure the unit has proper airflow, refrigerant, and electric voltage. I’ll have to see about getting these checked by a professional so that I can be sure the unit will last a long time.
Dennis Sanchez says
I really love what you said about making sure you have a professional maintain your HVAC systems, as replacing them can be very expensive. My brother has been a bit reluctant to have a professional come look at his system. I’ll definitely have to mention to him that they are complex systems and if not maintained, can be expensive replacements. My brother would definitely prefer not to have to replace the entire machine. Thanks for the tips.
Danni Black says
I really like how you said that a maintenance plan needs more than just filter and belts. We have been thinking about getting a new system for a while now because the previous owners of our home definitely did not have a maintenance plan. We will have to keep this information in mind while we get in contact with an HVAC contractor.
Steve @ Heating repair Denver says
Often, we think that changing the air filter can magically repair the HVAC. system. But, this is not the case. It is better to call the best HVAC service in the area and get inspection and tune-ups done periodically.
DHC Comfort says
It may sound simple, but you should change your air filters whenever they are dirty. In terms of how often, there are a number of variables to take into consideration: what kind of filter your HVAC system requires.
jresquival says
That’s a good tip to get an HVAC technician to look at your system once before each season. That way you’ll maintain your system for a little longer. My energy bill has been going up lately so I might need to reach out to a technician.
LNWeaver says
That’s right, refrigerant is really important too. Your system can’t move heat around without it. Try to get your system checked every season.
Dave Anderson says
I know that maintenance is important especially for HVAC systems because of how important they are to the comfort of your home. Like you said, I have been changing out the air filters in my system regularly, however, I want to make sure that my HVAC system is serviced. I think that it would be a good idea to find a company that offers servicing contracts so that it can get cleaned without me having to call and schedule it every couple months.
Bernard Clyde says
You make a good point that our AC systems will be becoming more and more complicated as they become more capable. I think it’s important that we try to understand what we can about these systems so that we can understand when to have them maintained or repaired. In the end, I think our ability to recognize potential issues will help us get the proper repairs for the air conditioning unit in time before more damages are incurred to the system.
Ridley Fitzgerald says
I had no idea that HVAC cleaning had so many parts to it. Filters are easy to change, but I have no idea how to clean the airflow, refrigerant, and all of that other stuff. I’ll make sure to hire a good HVAC contractor to help with that.
William says
Filters are super easy to change out, but my uncle’s family has been the worst about this. Every time I go over there, I swear that it’s the same filter he’s been using forever. I’m tempted to just buy a new filter and swap it myself. I get sick just thinking about the quality of the air in that house.
Ivy Baker says
This is some really good things to know as a new homeowner. I liked that you talked about how you should remember that dirty filters can really restrict the airflow. It does seem like a good thing for me to know as a new homeowner.
Acclaimed! Furnace says
We agree that some maintenance can be do-it-yourself but it’s a great idea to get a professional in before each season to make sure equipment is running at maximum performance and efficiency.
Jack Titchener says
I definitely agree on changing your filters. I just checked mine last week and I’m sure at one point it used to be white, but now its black. Thanks for the tips, I’ll be changing my filter later today!
Port Power says
I can agree that changing the filter is something relatively easy but still often neglected. Having a clean filter helps keep the air clean while helping the air flow more efficiently and not waste energy. It’s good to really point out the difference between having quality maintenance as opposed to a quick checkup and clean.
Kenneth says
I like that you mentioned taking into consideration the specific maintenance recommendations on your model. Not all systems are created equal and you should get familiar with yours. It may not be the most entertaining thing to read the owners manual, but it can save you in the long run.
Harper Campbell says
It’s interesting to know that when it comes to an air filter, that there are different things to help make it successful. I like how you pointed out that we need to make sure that all of the safety components are fully functioning. It might be a good idea to hire a handyman to come into check things out, just to make sure we did everything right.
Kourtney Jensen says
I hadn’t previously known that it’s recommended that maintenance get done before each hot and cool season, to verify efficiency. My husband and I just moved to our first home and want to stay on top of maintaining everything. This is great information to know, and we’ll be sure to have our unit looked at before the cold weather comes!
S.D. says
Great post, keep it up.
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Ridley Fitzgerald says
You’ve got some nice advice for HVAC maintenance here. I like how you said that we need to find a good company to help us run maintenance, and not just any one. We’ll be sure to do some research and find a real professional to help us.