How To Clean And Check AC Evaporator Coils After A Freeze Up

If you notice ice forming on the refrigerant lines of your air conditioning unit, or on the sheet metal around your evaporator, then something is not right. Typically you'll also notice that the air from the vents is not as cold as it should be. You should shut the system off and you can do some checking on your own before calling a pro.
Icing of the evaporator coils can be due to restricted airflow for various reasons, a control board gone bad, or low refrigerant levels due to a leak. That last item will require a pro to diagnose, but a homeowner can certainly check for other issues first. In this video I'll show you how to clean your evaporator coils and check other basic functions before you hire a pro.
Other videos referenced:
• Clean And Inspect Your... Clean And Inspect Your AC Condenser
• How To Maintain Your A... Maintain Your Condensate Pump

[@PassinGas9934]

I watched a ton of other vids on this same issue and was still just as lost. This one video has explained everything for me concisely.

[@brycapone7230]

The evaporator coils in that unit are in a V formation and you are only looking at the outside of them. If you removed that triangular panel in the center, you would have been able to look to see how dirty the coils actually were. The INTAKE side of the coils is the part that accumulates all the dust and dirt and I am pretty sure that was the center part that you never even opened. That is where the air first enters the evaporator coils from the return vent in your house. They needed to be brushed and coil cleaner used to clean them. Spraying water on the fins on the outside of the coils where the OUTFLOW of air returns the "cool" air to the plenum and then into the house is not going to solve the problem. Sometimes the INTAKE side of the coils cannot be accessed simply by removing a panel with a few screws. There are videos showing the person having to get down below the air handler and having to spray them through the opening where the return air from the home enters the air handler.

[@enduringcharm]

Well, the video was really about icing and the causes, not just cleaning. You are correct that taking apart more of the sheet metal would allow a more thorough cleaning of the coils, although spraying from the outside in will take care of the worst of it. Since the video is aimed at homeowners, there is going to be a limit as to how deep you want to go with disassembly.

[@JASON9I5]

I had to take off the V shape sheet metal to access the inner coils. That was the hard part since I had limited space. I had to bend the sheet metal to pull it out but finally got it. Your are 100% correct, the inner side was the dirtier side and literally had a thick build up of lint. After cleaning, I noticed significantly how much cooler the a/c worked.

[@ricknowak4582]

Bry , I have a problem with my cooling coils I believe inside of my condo near the air handler. Maybe you could help me out. An AC man came twice! 1st free on. That didn't work. He tried cleaning the coils. But I don't think he did it properly.

[@Staboogie777]

This happened to me last year and guy came and supposedly “fixed it” all I saw him do was hose everything down, replaced something and left.. literally the next day the outside coils froze again and he said “just hose them down and leave system off for a few hours” so basically he didn’t fix shit 😡😡🤦🏻‍♀️

[@subramanyamgopala1901]

❤Mine also impossible to clean the inner V. So I quit using our whole house AC and bought 2 mini split AC which cost $799 each. These are way better than conventional whole house AC.❤

[@ldawgprattlake1805]

If the coil freezes, turn the fan to on and turn system to off on thermostat. Will defrost much faster.

[@robertlamey7612]

If it’s a gas furnace turn the furnace on and it will melt faster.

[@Aikynbreusov]

So informative....it's exactly the problem I have and the video with a possible solution I need

[@shamrockfile]

Most helpful video. Not only did it describe my problem, it showed me how to fix it.

[@gerardclarke1664]

Good job man...best video for a home owner.

[@deejohnson5163]

I was hoping you were going to take off an end panel so you could clean inside the coil. Now that would make a great video. Thanks.

[@enduringcharm]

You could take it farther if you wish. Some sheet metal will be easier to remove than others, it will just depend on the brand and the physical space you have to work. In this case the coils were really not that bad, but if the condition is worse it might be worth going the extra mile.

[@rafaelgomez1989]

*** COULD A CLOGGED COIL CAUSE WATER LEAK ???

[@jcs6206]

The real problem was inside the "A frame". Need to remove the sheet metal triangle (good luck!) and then remove the 1/2 inch think layer of pet hair, lint, pollen, dust and other crud with a brush and shopvac. Replace filters more than you think you need to, monthly for many households, or this will happen.

[@enduringcharm]

Yes, filth can build up on the other side, although it isn't always the case. This system had a well maintained filter and the fan blades were clean. When filters are not maintained I notice dust build up on the squirrel cage blades. Removing the additional sheet metal to get underneath the A frame can be a lot more work, especially if rust is present.

[@barbaraadams8219]

Very well done video. Thanks for the thorough explanation.

[@m3j_channel965]

Excellent. Well done!

[@rgraz4929]

Great video. Thanks so much. My 35 year old condo furnace is only 12" W x 25" D. My evaporator section is only like 7" high. I opened the plenum at the seam expecting to see the A-coil extended way up into it, but to my surprise my coil was small non-A style 7" high with 4 or 5 condensate channels. I was expecting to clean underneath, but you can't with this style unless you pull it out. Am I correct? Thanks again.

[@enduringcharm]

There are a million different styles of evaporators and furnaces, so yours could indeed look very different. Sometimes it's not worth disassembling the whole thing, better to just clean what you can access and call it a day.

[@rgraz4929]

​@@enduringcharm Thanks for the reply! That's what I did. I opened the plenum and to access the evaporator access panel I had to bend down a lip of the furnace wall. To make things worse, the paint on evaporator coil enclosure was breaking down, very sticky and all over the place! Then I closed it all back up! lol. Screw holes never seem to line-up like the first time. Waste of time, but now I know what's in there. Thanks again.

[@hpmoxie4660]

Very nice! Thank you

[@trystanmccarthy2922]

Thank for the video. Do you know if i can use a 16x20x1 filter in a system that i just pulled a 16 1/2x21 1/2x1 out of?

[@enduringcharm]

All you need to ensure is that the filter will seal around the edges. In some systems there is no room for play, in other systems you may be able to slightly adjust the filter size and be okay. All you can do is shine a flashlight in there and see what kind of room you have.

[@FoxNewsNewYork]

Well done.

[@Survivalgearlists]

Excellent

[@OthmanAlikhan]

Thanks for the video =)

[@frankwilson9878]

How can you tell if you got your coils clean enough? Can you test by something a simple as shining a flashlight though the coil?

[@enduringcharm]

You're overthinking this. If you get the degreaser applied, leave it for a bit, and then the spray off looks clear then you should be fine. If you had debris in the coils, then once the spray off is clear you're good to go. You don't need to eat off the coils, the point is just to prevent build up over time. Watch the tray and the pump for clues as to how clear the water run off is when you spray.

[@scuffy44]

The problem is the air flows from inside the A coil to the outside. The major clog would be where you can’t see inside the coil. Usually take a little more than degreaser and and light spray from the outside. I have seen a 1/2 layer for dirt and dust clogging from the inside. This will cause major air flow blockage and freezing.

[@GeoHoleNoNe]

Hello, I have a question. Not sure if you’re familiar with high velocity a/c, but I just got a new Unico system in our attic , also a trane condenser. I clean the fins at least twice a year later in spring and later summer. I know it’s not a bad idea to have a yearly service but …. Because my system is new etc or even if it is new, are you really suppose to clean those coils in the modular Unico itself? Or don’t touch it unless you have an issue? Just want to know for proactive measure. Thx

[@enduringcharm]

I can't help you with that particular system, but I can give you some general guidance. You might be surprised at how easy it is to get hold of a technical representative at the manufacturer to give you an answer directly. Unlike giant consumer companies which make it impossible to call in and get a human, you can often pick up the phone and call the general switchboard at a small to medium sized manufacturer. I've done this many times and had a human on the phone in a few minutes or that same day. Give it a try.

[@gaga140012]

I went to clean my A frame ac condenser today, took of the access panel off the furnace there many lines running in front of it A sheet metal no access available. Without taking the whole middle section of the furnace apart to access the other end. Its a Lennox furnace, so how do you clean inside the A frame condenser, suggestions please.

[@enduringcharm]

I think you are referring to your evaporator (inside the house) rather than your condenser? Without seeing the problem in person I may not be much help. It may well be that you have to do extensive disassembly to get at the unit. Typically I will look for the condensate tray drain, and then find panels or screws in that area for access inside.

[@Charlydx21]

Can I use a coil cleaner spray? It usually sprays out a foam. But isn’t know it that water sprayer is enough to remove the foam. Probably gonna need the water hose. But is that too much water?

[@enduringcharm]

Well, you can use as much water as you want, the important thing is that you drain or vacuum up that water as fast as you put it in! If you want to do a more thorough cleaning you may also want to remove more of the sheet metal than I did in the video. In that case you may have easier access with a wet vac.

[@miked2503]

Hi. Thanks. We have a Magicpak unit in a closet in our condo. It's dripping water in the closet and down the outside brick when it's in AC mode. It's new. Filter is new. Installer says he needs to contact the manufacturer. Very frustrating after $7,500. Any experience with those magicpak combo units? Thanks.

[@enduringcharm]

Don't know a thing about that brand or model, but if you have water coming out during AC use, it's probably condensation. Either the condensation collection system was not properly installed or it is blocked for some reason.

[@miked2503]

@@enduringcharm Thanks for the input.

[@technolucas3720]

icing coils could indicate a low refrigerant charge.

[@enduringcharm]

Correct, that's what turned out to be the case at the end of the video.

[@williamkterrell]

Great job thanks for the information.

[@caraogg6230]

What cleaner is best to use ? You're opinion

[@enduringcharm]

Honestly, it's not that important. Any commercial degreaser, like 409 or Fantastik, will be fine.

[@gordm3527]

This exact thing just happened but my furnace coils are inside a duct and I have no idea how to access them.

[@enduringcharm]

Obviously I'm not much help from a distance, but if you examine the ductwork there must be a way to remove a section or open a side.

[@mrpoolplayer6379]

Is the cleaning of the A-Coil part of a general maintenance.? Mine is getting rusty, but if attended to, this won't become a failure... What say you...?

[@enduringcharm]

Well, some homeowners do no maintenance at all, and others do extensive annual maintenance. Is it a good idea to clean out the evaporator once in while? Of course. The need for it will vary, though, depending on circumstances.

[@mrpoolplayer6379]

@@enduringcharm I have my system checked twice a year, but after 8 years, I find that my AC Coil is about rusted into failure. I know they make stuff to clean, remove & halt rust, in it's tracks, but my maintenance people are lazy & looking forward to my purchase of a new A-Coil...

[@beachwave2]

What degreaser do you think is safest to use on the evaporator coils ?

[@enduringcharm]

It's not critical--any cleaner like 409 or Fantastic, etc. is fine.

[@josebenedico7379]

home Depot or Lowe's have

[@user-sh6td3kb8x]

I heard you can turn off the ac and keep the fan going to help it melt quickly.

[@enduringcharm]

Yes, that can be helpful if you have icing.

[@tracyneighbors7059]

A NEW AC COIL FOR MINE IS $650 PLUS HAVING IT INSTALLED, I WONDER IF I SHOULD GO THAT WAY OR GET A NEW UNIT? IT'S 40 YERAS OLD AND NOT HOLDING THE COOLANT THEY PUT IN, AND THAT WAS $200 JUST TO TELL ME THE AC COIL IS LEAKING IT OUT! ANYBODY THAT CAN GIVE ME ADVICE, WOULD BE GREATLY APPRECIATED, THANK YOU, GOD BLESS YOU'LL!

[@enduringcharm]

If your system is 40 years old, it's unlikely it's worth repairing. A new unit will be more expensive upfront, but it will be far more efficient (which will save you money) and all the components will be new and will last much longer.

[@tracyneighbors7059]

@@enduringcharm THANK YOU, THAT'S WHAT I'VE DECITED TO DO!

[@elvergon3963]

Would dirty coil can cause short cycle on my furnace?

[@enduringcharm]

So the problem is with your heat? It cycles on and off too fast? Typically something like that is related to the thermostat or the control board.

[@elvergon3963]

@@enduringcharm yes it does that. And also overheats. Last year winter was working perfect. But I just tuned it one yesterday. And goes on and off and sometimes the burner where the main flame is it totally shutting off.

[@elvergon3963]

@@enduringcharm it does heat up . But I can feel furnance cover gets too hot. And I have to keep resetting on os the switches. I haven't check the exhaust pipe yet. But since I got this place (mobile home) 4 years ago. And in every first start after the summer always short cycles till it reaches the desired temperature and after that works normal and no more short cycling. But now its just short cycling and overheats and like i said sometimesthe the the flame in the burner dies. I replace The flame sensor last year dues to pilot flame wouldn't stay ignited. Filters are new and clean. Thank you for the help. God bless you my friend

[@enduringcharm]

Well, it could be that you have a legitimate problem and the control board is shutting down for a good reason. The flame sensor is one item, or some other electronic issue. The control board is programmed to check certain things before start up, and the control board is also programmed with a start up sequence. It is possible that your control board is damaged or faulty. See this video as an example of what I mean: kzbin.info/www/bejne/mIOZm52KhMlom5o

[@elvergon3963]

@@enduringcharm perfect I will check on that

[@shivaatbw420]

Pls help! My coils are still freezing even after I changed the filters out. And my other unit to the ac is in my attic and I do not have a handy man whom will go up there to check it out for me🥺

[@enduringcharm]

As I mentioned, there are many reasons for coils freezing up--it may be time for you to call an HVAC contractor to take a look.

[@shivaatbw420]

@@enduringcharm ok, thank you.✨

[@NevaSleep82]

Check refrigerant levels and coil condition for restrictions and air flow. Make sure your air handler blower fan is not intermittent failing or not working at all.

[@keearun]

I am thinking of installing a UV light on top of the AC coils. It's suppose to stop any mold growth on the A coils and in the condensation pan. The air coming out of the vent will not have that freezer smell.

[@enduringcharm]

Eh, I don't know how effective that will be. Air moves through there pretty quickly and the ductwork system is many times bigger than the evaporator box. If you really have a problem with mildew or mold, it cold just as easily be located somewhere else in the system. A duct which goes through a warm attic or outside wall, for example. You might start with a thorough cleaning of the evaporator and pan, and make certain the pan is draining well. If the pan doesn't drain well and the water just sits it may begin to smell. Also, it's not uncommon for an AC system to be OVER sized. In that case, the temperature drops quickly and the system shuts off before moisture is removed from the air. The system does short cycles rather than longer cycles, and humidity remains high because it takes time for the moisture to condense and be removed.

[@keearun]

@@enduringcharm A few years ago, I had the entire A/C system replaced. I got 2 estimates, one asked for $6000 to do the job and they said all their parts and equipment is from Carrier. The other said they will do it for $1800. So I did go with the $1800 offer. Few weeks after the installation, I was getting a 'dirty socks/freezer' smell coming form the vent when the AC started cycling for a while. Couldn't figure out why and were the smell was coming from. I told a different HVAC tech about my problem and he told me that there are two types of evaporator coil being used in the industry. One that is coated with anti microbial and last the life of the A/C system and there are imported coils form China that are not coated and these coils will develop mold very quickly and create the smell. He told me that if I wanted to get rid of the smell, I should change the 'A coil' with a coated coil or install a furnace UV light near the 'A coil" that will be turned on while the AC unit is being used. I should have not cheaped out in the first place.

[@enduringcharm]

Hm. Well obviously there's a limit to what I can suggest without seeing it in person, but I can say with certainty that for $1800 you didn't get a new system. That wouldn't even cover the cost of materials a few years back, and certainly not today. The first estimate you got was in line with typical replacement costs. I have to wonder what the fellow did for $1800--was that just an evaporator coil replacement and you still have the original condenser outside? Or did he install a used system? I don't know, but I would suggest having a local established AC company come take a look before you too much farther and throw good money after bad. While there may be truth the the evaporator coil coating, that didn't even exist years ago and mold was not a problem then. You should verify that the airflow, refrigerant level and pressure, condensate tray, and condenser pump are all working properly before trying to add a UV light.

[@keearun]

For $1800 he replaced the inside coil and the outside unit. It looked new. I will follow you advise.

[@enduringcharm]

Yeah, something doesn't add up there. Maybe it was a unit that "fell off the truck?" At this stage, though, better to get an informed opinion on site before you spend more money chasing your tail.

[@HerrTweekCat]

Great video, your voice sounds a bit like Charlie Day

[@udokee7409]

What if the panel is covered with silver ac tape? I live in an apartment

[@enduringcharm]

That foil tape is used to seal ductwork from air leaks, so it's good somebody went to the effort to use it. If you need to get into a panel sealed with foil tape you would just slice it with a utility knife and then tape over it again later. You have zero chance of just peeling it off. However, if you live in an apartment your landlord should be responsible for AC and heating maintenance.

[@MfremM]

​@@enduringcharm My landlord raise rent or not renew the lease if you call on service, same as the cable guy. 😢

[@judithmcintyre5259]

Now I know how to clean them so my husband won't bitch at me for not doing it. 🤦‍♀️

[@glennandvirginiamencer9794]

in some situations the A-coil has to be removed. That requires pumping down the system, cutting the refrigerant lines, taking the unit outside to apply cleaner and wash off with a garden hose. then reinstall, braze the lines, pressure test, pull a vacuum and check the refrigerant charge. 3 to 4 hours depending on how easy the access is. And don’t forget to check the blower wheel. It might be heavily fouled also.

[@susie510]

Looked like the outside line insulation should be replaced.

[@behnkeee]

Cleaning the top of the coil is not very effective, I would suggest cleaning the inner V of the coil where debris actually accumulates.

[@enduringcharm]

The whole coil can be cleaned, there was just a limit to what I could film given the physical space.

[@realmadstupid]

Yes, usually the bottom where the air comes in can have a thick layer of crap while the top looks pretty clean.

[@ab-qn7kv]

How do you get to the underside. Mine seems closed off. Trane xl80. 2001

[@enduringcharm]

If you have the style similar to the video, there is probably more sheet metal to remove before getting to the underside.

[@caru3257]

Find where the return is and clean that side of the coil. 17 years doing oil heating and a little A/C.

[@joeb6947]

you didn't clean that properly/you must take off front cover and clean inside that A frame.That is where the debris are blocking air flow.Once debris carefully removed then use foam on outside to clean out fins.

[@enduringcharm]

As I did mention in the video, you can go further in removing sheet metal if you wish. If there is significant build-up of pet hair or remodeling dust or whatever else then you may have to go deeper. However, if the system filter was well maintained then pushing water through from the backside will force dirt to drop into the pan and it will also melt any ice, which was the main point in this video. The risk of going further in an older system is that rusted screws or sheet metal will not go back together. In this case the reason for the ice build up was not dirt, but a slightly undercharged system.

[@Indzeosko]

This guy missed the most important part.. Look and clean the inside ( Underside) of your A Condenser..

[@enduringcharm]

Actually, I think maybe you missed part of the video. First of all, you are referring to the evaporator, not the condenser. The condenser is the unit outdoors. Second, I mentioned taking the unit apart further in order to do a deeper cleaning, but I also mentioned that this can be risky when there is rust and corrosion because things may break. In this case the icing was NOT due to build up of filth on the evaporator coils but to low refrigerant. When that was addressed the icing went away. By gently forcing water through the evaporator coils with a sprayer as I showed in the video, loose dirt will be brought down to the pan below. If heavy dirt or other filth starts to show in the pan or if the water doesn't seem to be going through the coils, then you may choose to take the unit apart further and get access underneath.