Air conditioning maintenance isn't the sexiest of subjects, but fainting and peeing yourself from the heat isn't sexy either. With that in mind, let's learn how to do some basic air conditioner upkeep.
My central air stopped working a couple of weeks ago which led me to do everything I possibly could to fix it myself. Eventually, begrudgingly, I admitted defeat when I realized I wasn't going to have enough time to get my HVAC license before I peed myself from the heat.
The last time I had to work on my HVAC was when I replaced my furnace condensate pump which is easy to do yourself.
With my bedroom becoming a comfortable place to incubate dinosaur eggs or fire the odd piece of pottery I called a professional.
After doing everything I could, I added up all my AC symptoms and deduced my AC unit froze because I didn't pay attention to maintaining it.
Maintenance Tips
For the everyday DIYer.
1. Change/Clean Your Air Filter
- Replace or clean your air filters every 1-3 months. That's right - it isn't just a furnace thing. The AC runs through your air filter as well. A clogged filter makes your AC work harder. My air filter looked like a monchhichi.
2. Cold Air Returns
- Don't block any of the cold air returns in your house. You lose air circulation, humidity will increase in the home and the A/C is forced to work a lot harder. My air returns were covered by my Eufy (robot vacuum) & a dog bed.
3. Keep the Outdoor Unit Clear
- Give at least two feet of clearance around the outdoor unit to allow proper airflow. My unit was surrounded by a peony bush, agapanthus and rhubarb. Yup.
4. Clean the Coils
- The condenser coils of your outdoor unit are what make up the sides of it. Those fins that cover the whole thing get dirt, feathers, grime and guck built up on them. Clean the coils with a coil spray you can get at any hardware store. It's a spray foam you just spray on and then leave. (You can rinse with a regular garden hose if you want)
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To do a good job you should take the top off of the AC unit and spray the coils from the inside as well. I did this, but even if you just spray the outside without taking the top off, you should be good.
Before using a no rinse, foam coil cleaner.
After using a coil cleaner.
6. Clear the Drain Line
- The condensate drain line can get clogged with mold, algae, or debris. Use a mix of water and bleach or vinegar to flush the drain every few months.
7. Check the Refrigerant Levels
THIS IS THE BEST TIP FOR DIAGNOSING YOUR A/C!
- Check the temperature of the air coming out of your vents. Just set a thermometer on the vent. It should be about 10 C degrees cooler than the air in the home. (If your AC is set to 24C, then the air blowing from a vent should be about 14C) If there is less of a difference between your home temp and your AC air temp, you probably need refrigerant. The air coming from my vents was only 2 degrees cooler than the room air temperature.
8. Check for Condensation
- If your AC unit on top of the furnace has condensation it could be from one or a combination of the above problems (dirty air filter, low refrigerant, blocked air returns). I had condensation in connection to all of the above problems (brag, brag, brag)
10. Schedule Professional Maintenance
- Even if you DIY it you'll still need a professional technician to do an annual tune up. They’ll check refrigerant levels, motor performance, and electrical connections.
Performance Tips
- Make sure none of your vents are blocked. Not blocked by a couch, dresser, sleeping goat. Nothin'.
If there's no way to move your sofa anywhere else you can also get vent extenders that will direct the air away from underneath the furniture. - If you don't use your basement or it's getting too cold, close your basement vents. Since cold air drops, basements always get cold. Closing the vents will force cold air to other areas of the house where the cool is needed more.
- In the spring or fall when you don't need air conditioning but still want to cool the house a little, turn your furnace fan on. This will circulate the air throughout the house making it feel cooler.
- If one vent is blowing really strongly it's taking power away from vents elsewhere. Close the offending vent a little to allow airflow elsewhere. In older houses this can be done with the dampers in the basement.
- Don't turn your air conditioner off in the summer. Once it's cool enough outside, turn the temperature that your air is supposed to come on up a few degrees and open your windows. When your air comes on you know it's time to close your windows again. If you let your house overheat in the summer getting full of hot air and humidity before you turn the air on, it's harder on the air conditioner, more expensive and takes much longer to cool the house down.
Hint: If your unit has no power at all it could be because of a power surge. The AC unit outside has a box containing fuses that cut out to protect the unit in case of a power surge or short circuit.
O.K., well that was super boring, but it's one of those life things that just has to get done. Like emptying the dishwasher or pulling up all your floors to see if the previous owner left hidden treasures.
If you haven't done any of these things this year add them to your fall checklist. If you don't have a fall checklist you can borrow mine. Which is now updated to include AC maintenance.
Off to return my dinosaur egg incubator now.
Celia
I can't get to the outside of my wall unit, as it's in the stairwell of the apartment building. I do check the filter several times a season (here in LA, that could mean most of the year), and I clean off the covering grille. I wonder if I can spray the coils that face in to the living room... I bet the guys at Home Depot would know. I'm a big DIYer since our building management is sorely lacking in the service department.
Oh, and beware all the HVAC duct cleaning posts you're seeing on FB and Insta and related. They're all scams.
Karen
Hi Celia! If the stairwell is inside or protected it might not need the coils cleaned the same way an outdoor unit would. ~ karen!
lyanne hoefer
WOW! I just moved into a house with central air (first time I have had it) and I didn’t know why our electricity bills were so high...
Thanks for this info, Karen. I had no idea. The filter was filthy as was the coils on my A/C unit outside!!!
I appreciate all your info sharing ❤️
Addie
Great tips. I can only do some of them because my AC is on the roof!!! I don't know who's crazy building idea that was. It probably was a cheaper way to go. It is very common here in AZ.
It just doesn't make sense for upkeep or when you have an emergency and it is in the 90's and the poor tech has to climb on the roof!!!
Kristin S.
Our AC unit died in early August. Had a service check it out, and we had a refrigerant leak, the condenser coils were clogged up, and it turns out the unit was 25 years old! So we paid $300 for the necessary repairs while we shopped around for a new AC unit. Ten days later, we replaced it with a newer unit that is quieter, more efficient, and we had them move it to a better location in full shade. It may seem dumb to repair something we knew we were going to replace, but $10 a day per person when it was 98 F / 36 C was worth it to be able to sleep!
One point about AC issues they mentioned was you don't want mud to splash up on your condenser coils. If you have bare dirt around it, it will splash up and clog faster. They suggested laying down rubber pavers around it to control the splash factor and make it easy for service people to work on it. That was a cheap and easy tip I hadn't heard before.
Oh and a new AC for a three bedroom, 2 story house about 2100 square feet was $6K. That's with discounts for having a veteran, a teacher, and a cute dog in the house (that's literally what the contractor said!). They did throw in a free duct cleaning, and that was also shocking. The inside of the ducts looked like grey and black shag carpeting. Shudders. I seriously don't think they'd been cleaned since the house was built in 1950.
I do now have consistently cool rooms and much better air flow in the house, but oh man, August was an expensive month here.
Babs
"The King" lets me hire this out. Thank goodness. I do not need another thing to do!!!!!!
H
As single 62 year old Queenager who bought and loves her wee cottage/home really appreciates the diy tips. Always looking for direct easier ways to tackle maintenance as I have a crawl space and do not prefer a long visit when down there. The images of a skeleton hanging on to my back pocket every time I crawl out continues discussions in therapy. 😄So thank you for this. 👍🏼
Karen
I'd be more worried about the centipedes than the skeletons. And then of course there's the potential for centipede skeletons. Shudder. ~ karen!
lyanne
I hope you had (or plan on ) encapsulating that crawl space. I did mine 2 years ago and the difference in my home’s humidity ( in summer) and warmth (in winter) is miraculous!
Lynn
Useful as always!
Deb from Maryland
This info is excellent - and I can do this! Thanks. :)
Lynda
Just got a brand new heat pump in May that has it's output up on the wall. Still need to clean pipes and coils though. Could not believe how much poplar fluff got stuck on it in June. 2 inches thick!!! Yay handheld battery operated vacuums with soft brush heads.
Mary W
That tip about the bleach in the thingy is VERY important. Mine didn't have access to that inside and so my line froze and the repair man explained it all to me. He is a special repair man that shows me how to do the stuff myself. When a hurricane came last year, as soon as it passed, he parked his vehicle at the worst hit area and just stayed there helping people get AC's going. All that to say, he is kind, knowledgeable and sharing. He did install a new access for me to use the bleach tip and guess what - no more frozen lines and repair bills. I hope he never moves away from our area. He is Karen in male form! You are also kind, knowledgeable and sharing but you are also funny when makes learning a lot easier for me.
Sarah
I live in Florida and it is getting hotter each year. Thanks for the tips!! My air conditioner is in my top 10 of things I am grateful not to include people.
Randy P
No central air in my 96yr old Chicago brick bungalow with hot water radiators, so I use small window A/C units to survive the Summer. Yes, they too have filter screens which need cleaning during the season. Good reminder, thanks. Hope you didn't get clobbered too bad by the A/C tech.