HVAC Systems Fail to Cool, Cause Worry
Homeowners are experiencing issues with their HVAC systems, including insufficient cooling, potential refrigerant leaks, condensation problems, and damage from improper installation. These issues lead to discomfort and financial concerns.
SOURCES (60)
“Me and my wife bought a house in April. We have had several excessive heat wave stretches and our unit has been able to keep the house at 70 the entire time. The past couple of days we have had hot weather in the mid…”
“Central NC. Record heat. Just moved in. 95-100 outside. AC set to 65. Unit is a year old. Won't cool below 75-78 during day but drops at night. Still at night, wont go below 67/68 "Tech" came to look at it but it was a no name guy who kept referencing the landlord by name and said he installed the unit a year ago. Told us he owns his own contracting company. Seems to be a fixer of sorts. Said it gauged properly. I saw the screenshots and appeared accurate. What's going on?  ”
“So i had a 22 split and everything inside was reading fine. outside was a different story. i have a hard time understanding why my super heat was 20 and subcool was 3. homeowner said their AC is running fine in their likings. i just want to understand why a lot of AC are like that. i came across a lot and like i said i just want to understand it more. #newtech submitted by /u/WholeEntrepreneur790 [link] [comments]”
“My HVAC is 5 years and 5 months old. Builder, and I, didn't register the HVAC, so out of warranty of 5 years. Airflow has gotten worse over the last week and now there is almost no cold air coming out. Blower looks to be working well. HVAC Company says there is a clog in the Evaporator coil and needs to be replaced. They said everything else including the TXV looks good. Other quotes over the phone for the evaporator coil replacement are around $4k to 5k, Charlotte, NC Area. submitted”
“I have a tech on the way, but I am curious to see what the HVAC experts of Reddit have to say. Yesterday I came home to a thermostat that had run out of battery. So I did the following: Problem 1: Thermostat batteries are dead Pulled the thermostat off the wall, replace the battery. thermostat comes back on and I stick it back on the wall. Result: No dice, system won't turn on, though the thermostat is calling for air Problem 2: Thermostat is running, but no air. I pull the thermostat back o”
“Hey everyone, my AC seems like it’s struggling to cool the house properly. It was keeping it about 17 degrees cooler than the outside temp yesterday, but today it’s only currently cooling it 4 degrees below outside temp, and the app says it’s been running for 20 hours. The copper pipe going into the furnace has some condensation on it, which online I read means it’s frozen inside and I should just set the fan to the on setting. I also noticed some cold air blowing out through the hole in the pho”
“My air conditioner has been struggling with the over 100 degrees Fahrenheit weather to the point where it would keep the house cool, when when it got into 100+ the home would go up to 80, we assumed its bad insulation, the builder was a cheapskate, but today the highest outside was 80, the house should have easily remained a cool 72 to 75 and it went up to 80 again, that's when I knew, something is wrong. A week ago, I could feel nice cool AC air coming from the vents, but today, it just fel”
“I don't have much experience with HVAC systems, or building codes, but even I'm thinking something might be structurally wrong where I'm renting. I'm in VA if that's at all helpful. Roughly three years ago, I began renting a small townhome which had been converted into a duplex shortly before I moved in. The basement was separated off from the top two stories, and converted into a second apartment that the landlord rents out. Certain things seem right, the electricity is spli”
“Looking for advice on how to handle issues with an HVAC installer that 1) failed to perform proper system maintenance under my paid service plan, leading to significant system performance decline. 2) Failed to follow the manufacturer’s guidelines on surge protection (it’s an inverter system and they didn’t install it with a surge protector). 3) Failure to register me for the manufacturer’s warranty, despite saying they would take care of all warranty, rebate, and permitting paperwork. I have a 5”
“Our upstairs air handler isn't running. I've spent the past 2 weeks diagnosing it but I think I've reached my limit. It started when I realized I hadn't checked my filter since last winter and it was pretty dirty. Changed that out but the coils were already frozen. That led to the drip pan being flooded. Drained the pan and we were back in business. Ran at 77 for a few days. Wife turned it down to 73 and within a couple hours it had frozen over and turned off. Went back up and th”
“This box is by the fan unit outside. Is there something supposed to be in here? What can i check? Maybe a breaker somewhere? submitted by /u/soldieroscar [link] [comments]”
“I have a 2 story home with 2 ACs. Both are less than 10 years old. My bedroom is on the first floor and noticeably warmer. I have checked the duct to feel the air coming into the room. However, if I shut my door I can feel what is essentially a constant stream of air being sucked out of the room. How do I fix this to keep my bedroom cool? submitted by /u/Platypus_God [link] [comments]”
“It's been pretty hot (mid to high 80's) in SoCal since I moved in to this new place 2.5 weeks ago. The central AC has been a godsend but im a first time homeowner and this will be the first AC system I can call my own. It's finally cooled down 67° at night and I just came home to this sound. Is this normal? Sounds very different from the sound it's been making last few weeks. Checked three times at different stages (right after turning on, 5-10 mins in, again after it had cycled”
“Hello all, Today I decided to see about draining and cleaning portable AC had for a few months as past week it hasn't been keeping up for the room despite blowing cold air. Might be due to heat wave where I am located but its a 12,000 BTU portable Element AC. Anyway after I tilted it slightly to make sure water was drained I hooked it back up and I turned it back on after a few minutes it started making a noise. Can't really describe how it sounds. I took apart the back of it to look and”
“I live in an apartment and I am wondering if the AC is broken. It was cool the past few days but this has to mean it’s broken now. Not sure what to do and figured I’d ask here. submitted by /u/ItsACCRUALworld_ [link] [comments]”
“I’m in North Georgia. It’s been a hot summer and on the hottest days, my AC cannot keep up. The attic is 140ish degrees and I have been trying to decide what avenue to take to fix the problem over winter so next summer isn’t so bad. Here is a single picture of the attic. The baffles seem too narrow? I have hardie board soffits and the ridge is vented. Should I try more baffles (they are only every other rafter bay and sometimes skip more than 1)? Should I also do attic foil? Should I entertain a”
“We’ve got a heat pump, Bryant Quantum Plus, that has started developing an issue. Every once in a while the blower in the house will kick on but outside, the fan/compressor will not. I’ve got my procedure down…pull thermostat (Chromotherm IV Plus) off wall to reset, pull outside fuse at compressor, flip breakers off and back on again in basement, plug fuse back in, plug thermostat back in. Majority of the time the thermostat will display a little “Wait” in the corner and after a few minutes the”
“Tried to capture it as best as I could. Central AC system in a condo in SoCal if that matters. Thank you all in advance submitted by /u/Fakiiri [link] [comments]”
“Seeking some advice on the best course of action. AC froze over a couple weeks ago and I had a tech come over to diagnose. They pointed out that the pressure was 105 on the low side and 300 on the high side, and the supply - return temp difference is around 12F. The tech opened up the air handler and used a leak detector which showed a few leaks around the evaporator coil. For context, the system is a Lennox 3 ton unit with R410 that’s about 9.5 years old and has been seeing a decline in cooling”
“Looking for feedback on performance of my HVAC system and potential short cycling. Background: Live in Northern Virginia (about 1 yr in the house) Approximately 2,300 sqft two floor house (lower floor is partial daylight) built in mid 70s Approximately 5 year old 3 ton Trane system System is in lower floor with returns on both floors Attic recently air sealed and new blow in to R49 Windows are vinyl and newish Thermostat (programmable Trane) is right under the large return on the upper floor So”
“Got this installed over the summer. Replaced existing 3 ton that was 13 years old. I’ve got a couple issues: 1) humidity is high on second floor usually 60-65%. 2) I know it’s hot and humid now (in south texas) but it even struggles to get down to 71 setpoint at night. The temp delta from intake to supply is around 15 degrees in most places but varies. The filters are new. The flow seems low out of vents but I don’t have a way to actually verify that. I’m wondering if I should get a different co”
“In Dallas where it’s a 100 degrees and of course the a/c stops working on a Sunday! I call the a/c people who came out 2 months ago to fix it and after 8 hours still haven’t heard back from them, even though they have 24/7 plastered all over their website. So I decide to see what I can do on my own. Back to 2 months ago, a/c stopped working, I call out the a/c guy, and he replaces the capacitor. A/C unit is from August 2016 so it was just barely under the 10 year warranty. It’s been working fine”
“Had a new AC unit installed about a month ago. Three story house - this is the unit for the top floor. It’s located in the attic. After about two weeks it quit cooling properly. First technician said it was fine, we just needed to keep the second floor cooler (I wasn’t there, this is what he told my wife). After a few more days with no improvement, we called them back out. New technician took about 10 minutes and said the compressor was not working properly. They replaced it on Friday. My son an”
“To preface, our AC unit is old and i realize it really just needs to be replaced. This is something i plan on doing next year. Currently it’s going to be 100° out for the next week and my AC unit runs for 20 seconds shuts off for 5 seconds or less and then runs for 20ish seconds, rinse repeat, 24/7. There’s not much I’m going to be able to do about it right now but why is this happening? Thanks in advance from a sparky👍🏻 submitted by /u/boomsticktings [link] [comments]”
“I’m a renter and just had my ac replaced in a 1400 sqft home with a 3 ton Goodman unit. It’s 95 outside and the lowest I can get it inside is 77 in the rooms closest to the blower unit. rooms further away are around 80. Air coming out of vents is pretty week and ranges from 68-75 degrees pretty much going in order from shortest to longest distance from air handler in the attic. Guy who installed it said it’s normal but it’s doing worse than the unit that was replaced. Really think the guy is ful”
“Hi y'all, I'm a new homeowner with no HVAC knowledge. Any suggestions on what type of service to contact to diagnose this HVAC issue? And would "duct cleaning" be considered a scam in this case? The issue: The master bedroom's vents aren't providing much airflow when you stand directly beneath them, which ultimately leads to a ~7°F differential in temperature. This means we're either cooling down the full house a lot just to get the master bedroom to a decent temp,”
“Hi, I posted this in another subreddit but wanted more input so I can put in a maintenance request asap if needed. my apartment complex recently added insulation to the attic space just yesterday and ever since my ac is about 4-5 degrees hotter than usual during the day. At the moment it is 95 out and it’s 80 to 81 degrees in here…prior to this it would maintain about 76 to 77 in these temps. I put a meat thermometer in the vent and it read about 65 so there’s a 15 degree difference in what’s bl”
“Was cleaning around ac unit and noticed all this build up. Is this something I can fix myself or do I need to call someone submitted by /u/CardiologistSilver43 [link] [comments]”
“So, recently I had had problems with my indoor AC unit short cycling and freezing up. I called a hvac technician. He checked my freon levels and said it was perfect. He then changed my thermostat to a newer digital thermostat. When it continued to short cycle He went and started looking around my AC unit. He said there was something wrong with the motor fan and it had to be replaced. They quoted me $1000 to order the part and install it. Is this a reasonable price? They also told me to keep my f”
“Hey howdy, We just bought a house. The house smelled fine on tours/inspection. The home inspector told myself and the previous owner to run it "on" all the time instead of "auto". Previous owner does this, house goes empty for a month as we move. We are in a humid area and this was a peak humid month in our area. We move in a month later and there is now a heavy musty smell that attaches to everything clothes, bedding, towels etc etc. I cracked open the coil housing and found”
“I turned on my a/c to hot for like 2-3minutes on Sunday. And since that, I’ve noticed that my a/c is blowing cool from the driver vent, but each vent you go across until you get to the passenger side, it blows warmer and warmer. The passenger side doesn’t have any cool coming out of it. Anyone ever experienced this before? It’s been happening for a week btw - today is Friday. Any DIY solutions? It’s 2012 Automatic Jeep Patriot I think it’s a 2.4 L4 submitted by /u/Immediate_Holder [l”
“I have a 3 ton Lennox R-410A installed in ~2013. The coil was replaced under warranty because of a leak in 2017. It now has a 2017 ADP evap in it. My HVAC tech came out because I was having freezing issues. I got those issues fixed with a cleaning and a top up of refirgerant. I got them to do a leak test this week - they found small leaks in the evap and condenser king valve. Their recommendation is to replace the system. I asked for a quote to replace the warranty covered evap and the king valv”
“My condo was built in the 90s. We recently replaced our outdoor condenser unit with a heat pump, but I feel like it still takes a while to cool the house down at night. One thing I saw brought up was leaky ducts. Is there any way for me to personally check that? I live in the top floor of a condo, and I'm not even sure how to access them, aside from looking inside the vents. I purchased one of those cameras on a cable that connect to your phone. Also heard air pressure could be a thing. Also”
“This is a 4yr old AC/Heatpump and when I went to change the filter today, I noticed some blue residue at the foot of the unit. The blue residue looks like its coming from the large copper insulated refrigerant line. When I unwrapped the insulation, a few drops of water came out. I imagine a little condensation drip like this is someone expected, since we've been running the AC almost everyday this month. Or is this the sign of some other bigger problem that is about to reveal itself? The res”
“I was just notified that the outside unit for my split-air AC system needs to be replaced because of a leak in the true suction line in the condenser. Is this something I can get a second opinion on as a serviceable component or is it absolutely necessary or me to replace the entire unit? Thanks Edit: The system is around 4 years old. submitted by /u/Skip2MyPou [link] [comments]”
“Is this thin pipe suppose to be cold and have condensation? Or is that a sign of a problem? We are troubleshooting an AC that has issues intermittently. While testing the capacitor, I noticed this line sweating and it was cold to the touch. Thanks for any help! submitted by /u/Dolce17 [link] [comments]”
“My AC went out last night. I live in the South but it’s thankfully rather cool right now for this time of year. I had some help tonight (thanks, Dad) and discovered this leak. Looks like the leak caused a switch to shut the system down because there’s too much water. submitted by /u/DJWolfMan2342 [link] [comments]”
“Anyone know why this is doing this? I unscrewed the front panel and sprayed the evaporator coil with foaming coil cleaner and rinsed it away afterwards. I then sprayed the blower wheel with concrobium and put it back on. Now days later, the outside coil is doing this??? I never even touched the outside coil. submitted by /u/C131331 [link] [comments]”
“Hello all, Regular central HVAC on a Texas house. Outside condenser, inside unit in the attic/closet, ducts, the usual setup. Tech found a rusted liquid-line filter drier, took it out, put a straight pipe in, pulled vacuum, and recharged. After that it blows cold for about 20 minutes then turns warm. Mornings when outdoor is 70–85 it runs longer, about 45 minutes, supply around 65F. When it gets hotter/sunnier, supply climbs to about 72F and it stops cooling right. Outdoor fan is spinning. Wet s”
“2016 doddge challenger 6.2 v8 Replaced ac condenser vacuumed system Ac worked for 2 days now it’s blowing hot air. Drained the system vacuumed it again and tried to add refrigerant this is what’s happening Also when I unplug and plug the pressure switch the pressure changes Need help Thank you submitted by /u/TBGBigSteppaTx [link] [comments]”
“2016 doddge challenger 6.2 v8 Replaced ac condenser vacuumed system Ac worked for 2 days now it’s blowing hot air. Drained the system vacuumed it again and tried to add refrigerant this is what’s happening Also when I unplug and plug the pressure switch the pressure changes Need help Thank you submitted by /u/TBGBigSteppaTx [link] [comments]”
“Had a new AC installed in June 2026 and today noticed it wasn’t working. It appears it has frozen up. The air filter is pretty new just recently changed. What would cause this? Need to get the company who installed it back out here. submitted by /u/dragonlovercolorado [link] [comments]”
“Wife called and said my ac unit was making a weird noise. Got home, felt the air being blown by the fan outside and it was ambient temp. Measured herm to common with wire off herm side and this is what it read. I’m headed to get a new capacitor but I just wanna make sure. submitted by /u/ImaginaryMenu1581 [link] [comments]”
“This is the unit for my office at my business. Office area is about 2,000 sqft. Warehouse (gym) area is 4,000. We only AC the office. Unit is above the office (open deck area). Outside unit is on the roof. Had one of our clients who has an hvac company come in and add a whole unit media box filter and clean the coils on the inside unit and add another duct to one of the offices that never got enough air, maybe 3-4 months ago. Yesterday AC stopped blowing cold. Figured it was iced up from clogged”
“Thank you in advance to anyone who can offer some advice. I’m a senior citizen that’s alone and is learning to take care of things without a lot of help. I have a 10-year-old Carrier split-system AC. R410-A. I know it’s getting up there in age, and I’m hoping to get another two years out of it. I live on the NJ coast on where these units don’t last long. Yesterday, I had a new motor, fan, and capacitor installed. The technician also checked the refrigerant and said it was a little low. His readi”
“Hi all, Just looking for some additional info from someone who might be in the know. I’ve had my ducted AC system replaced. Our installer has had problems getting it up and running. The brand is Daikin. It’s their sky Air range. The install required re-use of the existing copper pipes. The installer has lodged a call out with Daikin and they’ve already decided they will be replacing the PCB board without actually checking the install. They’re just going off what the installer has told them over”
“Hello! We just got service done through a company here in the bay area and this is their second visit after injecting dye the first visit. I guess some sort of coil was leaking refrigerant and we were advised it's not fixable and we'd have to replace the entire ac unit. The current units age is about 6 years old. Would just love to get a second opinion on this or confirm that this is truly a lost cause. submitted by /u/Suspicious_potato96 [link] [comments]”
“This is less of an advice post and more of a cautionary tale post. TL;DR: Do the cheap and easy stuff first. I bought my house about 2 years ago and it has always had pretty high humidity (hovering around 60%) and poor balancing between the open-concept high-ceiling main living area and the normal 8ft ceiling office, guest bath, and second bedroom. My system is a 2.5-ton central air unit with the evaporator coil, furnace, and blower sitting in a closet at the center of the home with a supply ple”
“AC unit went down, see photo for the model it’s an older Trane, overall it’s been running ok for years, yesterday it went out and 1500sf house is now 85 degrees. My buddy is an hvac tech and said one of the coils under the fan is bent and leaking some coolant, rub leak. The interesting part will be when the home warranty company comes out tomorrow to see what they wanna do, I’m hoping they cash the system out. Not sure how fixable this is. I’m sure they will try to bandaid like they do everythin”
“Hello everyone, My vents give occasional damp towel smell when ac is on and honestly almost feels like making the house feel tiny bit humid. I got 2 ac/ hvac people come in. One said your coil is dirty and needs cleaning, we need to apply uv light and sanitize and clean your ducts agains fungus and such. Other person came in today and left stating below “I didn't find any signs of standing water fungus in the evaporator coil or blower compartment. I did find that both were impacted with dirt”
“HVAC unit in attic is sweating like crazy. It’s hot outside, but it shouldn’t be sweating as much as it is. I had a tech come out and he states the aux drain ports need to be plugged. He feels as if water is leaking through here and getting into the internal insulation as a result creating the condensation I am seeing. The internal insulation is very wet. I noticed last week the pan underneath was almost full. I shop vacuumed the excess out and it’s starting to build back up. Slowly, but it is b”
“Hey all, My AC was blowing air in the home constantly and not turning off. I realized it was because it wasn’t actually cooling the house and was just running air. I checked the supply vents and it wasn’t cool air. I went outside to find my unit not running. I observed it to try to turn on by hearing a buzzing noise but turned off after a few seconds. It would try again a little after with the same result. Fan doesn’t move I would assume because I didn’t hear it (I didn’t visually check; was in”
“I'm not the one with knowledge about HVACs, my dad is, so I might not be relaying all relevant info. A couple months ago the coolant line evaporator coils on my parent's central AC unit have started icing up when the thermostat is set to 76F and below. My dad has some experience working HVACs and can't figure out why it's suddenly reaching freezing temps. He's checked for refrigerant leaks and couldn't find any, refrigerant (R22) levels have been checked and recharged/top”
“Feels like they forgot to put in some screws when installing submitted by /u/Dazzling-Inflation91 [link] [comments]”
“I went to change the air filter and it’s wet inside. submitted by /u/Weekly_Bison_2881 [link] [comments]”
“Hi all, Recently purchased a home with a 3 ton Rheem heat pump and love having central AC now. Had a few consistent 90° days and noticed the cooling wasn’t great - went into the air handler and saw that the evaporator coils were frozen. I turned off the system, replace the air filter to be cautious, but haven’t had excessive heat to re-try it out. One thing I noticed when doing that is it’s just a small 14 x 14 filter that services the whole unit. That inlet seems kind of small, is that typical”