HVAC Systems Fail to Cool, Cause Worry

“I noticed this during routine maintenance when they have the system off while inspecting things and cleaning the coils. So it's off for about an hour or two. For about a day after the system pumps out some extremely cold air. Where as after that day or so, the system isn't as cold. If that makes sense. What's the reasoning for this? Could that indicate an issue, or is that something normal? submitted by /u/WhatDoADC [link] [comments]”

“System not cooling. Airflow is good with a clean filter, strong airflow coming out of the vents. Small copper line isn't warm like it's supposed to be. Large copper line isn't cold like it's supposed to be. Fan on condenser unit is running. I'm guessing something is up with the compressor. Either that or the capacitor is shot. They have one capacitor for the fan and one for the compressor. And of course it happens just as the system no longer has it's 10 year warranty. I”

“I had an hvac guy come out and check out my system. I took a picture of the readings. He was saying I was under a lb low of refrigerant and that it would be 300 dollars to top it off. I didn’t have him top it off because it seemed like he was trying to sell me the top off. Was the guy being honest or just trying to make a few extra bucks? submitted by /u/Xtradifficult [link] [comments]”

“My AC died this year: the evaporator coil inside and the compressor outside. My question is if it makes sense to just replace the compressor/coil or if I should also replace the furnace. The furnace is 14 years old and according to my hvac guy in very good shape. But it's still older. Obviously theres a higher cost to replacing the entire system (though with potential bundled savings) but if I just replace the AC/coil will I run into any issues when the furnace dies down the road? subm”

“I need advice or to know if this has happened to anyone else. ​I installed a new GE Heat Pump unit. After installing it, the low line was reading 90 PSI. I added refrigerant R454B, and it wouldn't go above 125 PSI on the low line and 300 PSI on the high line. The low line temperature is 68°F and the high line temperature is 75°F. The thermostat setup is correct. When I turn on Cooling, it doesn't cool, and when I turn on Heat, it continues running in Cooling mode. I configured the thermo”

“Hello 👋 I had my ac running for the last couple days after having it off for a week or two. I noticed yesterday it was having trouble coming to temp. I went outside to the unit and noticed nothing was running (fan/compressor were silent). Even though it was calling for cooling. Checked the breaker nothing tripped. Turned off cooling overnight. In the morning, called for cooling while in front of the unit. Buzzing sound but no fan movement. Using a stick I bumped the fan noise went away as fan s”

“The AC blows warm air. The tech found a leak in the indoor evaporator coil. The recommended solution the replacement. The quote including the part and install is $3k in SC. Career 3 ton. Is the replacement only a solution? Is the quote reasonable? submitted by /u/came_to_find [link] [comments]”

“Hello, hoping to get some advice on an issue I have with my AC. For reference: I live in central Missouri, and I have a Lennox Elite HVAC system that was installed in April 2015. This all started last Friday (10/9). We had our water heater replaced on Friday, and in order to get it up to code, the plumber installed an electrical disconnect to the water heater that was not there before. I’ve been told this detail is likely irrelevant, but wanted to include it just in case. Noticed on Friday after”

“A leak was discovered on my outside condenser coils this week, just had the system refilled with refrigerant. I’m currently getting quotes for a new unit. My tech mentioned the leak was on the “high side,” and said don’t expect the fill to last long, which makes sense. Does running it less help? Or does running it more buy me extra time? Or is the pressure in the system constant and it doesn’t matter? I’m trying to decide if I need to rush to replace this week, or if I can wait a few weeks. I’m”

“Having 3 ton Goodman compressor replaced on 10/24 in NJ .. can the system be properly “dialed in” - subcool, high side etc in cool / colder weather.. or is that just a myth? Best to wait til warmer weather? submitted by /u/GeneralRant [link] [comments]”

“We got this heat pump and air handler put in about 2 months ago. I just looked at where I think the refrigerant line comes into the air handler and I noticed this sticky or lubey kind of stuff forming a ring around where the line and nut meet and not quite dripping but collecting on the underside of the line an inch away or so (bead visible but out of focus in the picture, I just touched it which is why the bead looks weird). I called them back out like 6 weeks ago about a whistling noise which”

“Air stopped flowing. I can hear the air handler running but no air coming from the vents. Any help is appreciated. Thanks submitted by /u/y0un63r [link] [comments]”

“AC running but blowing damn near 100 degrees. Woke up around 5:00am this morning in a complete sweat :( submitted by /u/kebmpb [link] [comments]”

“So my unit was on turned on AC but not cooling in the home. I went outside and the unit's fan needed a nudge to get going and then it was blowing cool air from the top. I changed the capacitor out and when I turn the unit on via thermostat now, I hear a click like the unit wants to turn on but nothing happens. The fan doesn't start or anything. I turn the unit off and hear a click as well like it is powering off. I switched the capacitors again and get the same result now, clicks and not”

“So to start out, I live in Southwest Florida and it’s especially hot and muggy. My AC has been working fine up until this morning where I woke up for work and noticed that I could hear my outside condenser unit running, and the air handler blower was not blowing air through the vents. I then went outside to check out the condenser, and the fan was still operating, but noticed that the compressor was completely iced over and the larger copper line into the condenser was also frozen. I went back i”

“Noticed today that the AC flow wasn’t blowing very well. I checked the air filter and it was a little dirty but nothing crazy. Noticed the line going to the box had a piece of ice on it. So I went outside and the compressor is completely covered and encased with ice! What’s going on? submitted by /u/RemoteEmotions [link] [comments]”

“so my ac(2025 blue star ac idk the model so i attached the photo)stopped cooling for 4-5 days and then i booked for the same complaint on urban clap(all round appliance servicing app in india) the guy came and said there was no gas in my compressor and there were leaks on the pcb side of my ac,he said he had to remove the indoor unit and take it with him to repair it and will re install it on the next day,now he installed it today filled up the gas and it is cooling but there is some noise from”

“Just moved into an apartment and there's a musty smell every time the AC kicks on. Maintenance cleaned the coil with a spray and a scrubbed with a SPONGE. That flattened some of fins, and the smell is still mostly there. (maybe slightly improved) A few questions: Is this level of buildup on the coil, blower, and panel normal, or worse than typical? Could this be what's causing the smell? Is it reasonable to push the complex for a professional cleaning or replacement of some/all of this?”

“My previous post.. (snapshot of it below). https://www.reddit.com/r/hvacadvice/comments/1vuqh0q/brand\_new\_setup\_doesnt\_cool\_at\_all\_texas\_hvac/ Quick Recap:-- I have some questions below AC installed on August 17th AC didn't work on day 2 took days for them to come out again in over 100 degree TX heat it failed inspection by 5 counts they repeatedly canceled the duct cleaning until I said forget it (pretty sure to make up for the labor of the code violations) they canceled the code vi”

“Haven't payed attention before now. But I think this w/e is new? We are having issues with the ac not cooling our apartment. submitted by /u/SleepyKikiRs3 [link] [comments]”

“I've got a bad coil leak and wasn't sure if I should repair or replace Hvac, and if what they're recommending makes sense. It leaked to 40% in just a month after being filled up. I have a 1,650 square foot house single stage Hvac with a furnace for natural gas for my heat. Current Hvac model: Lennox 14ACXS030-230A22 (2.5 tons; single stage). Vents and inside coil is in attic. Warranty never filed and unit will be 10 years old next year. They said it makes more sense to replace it wit”

“was told I need a complete replacement. the service guy wasn’t even willing to clean anything, said it all needs to be swapped out. the AC worked through the summer, keeping 2000sq ft cooled to 73 degrees at all time. and the heat works well so far this winter. should I be concerned or keep rocking? submitted by /u/Dramatic-Manager5509 [link] [comments]”

submitted by /u/M-lifts [link] [comments]

“Hi! I recently found a refrigerant leak in my evaporator coils (from 1988) after measuring the pressure in the suction and liquid lines and using an NLM1 refrigerant leak detector to spot the leak’s precise spot in the evaporator coils. While I figure out how to approach my HVAC replacement (hire vs DIY, repair versus replace, new versus used, which brand, etc) and make the changes, I thought about installing some 5000 BTU on the 17-inch window opening of 2-sided sliding windows (17 inches per s”

“Good afternoon all, unsure where to start. House is cooling but feels pretty humid. We keep it on 70 for the warmer months in east NC and havent had an issue. I pulled some snot from the line at the p-trap earlier this week and thought it was good to go, but still feels humid now a few days later. Unsure where / if I have an air handler or if its an all in one. Ducting is under the floor in the crawl space, house is single story, nothing in the attic, air returns are in the closet. Havent had an”

submitted by /u/NationalHat575 [link] [comments]

“I’m in Indiana, IECC zone 5A. My hvac guy diagnosed why my AC’s condenser fan and compressor works but air coming out of vents weren’t cold. Turned out freon all leaked out after last charge and evap coil was rusty and oily. My home is single family detached. 2 story 2300 sq ft vinyl siding 2002 build with 700 sq ft unfinished basement. HVAC system ducts to and has air return from all 3 floors. He recommended replacing the 24 year old Bryant 3.5 ton AC and gas furnace instead of repair. Gave the”

“So recently our family moved into a new 2 bedroom apartment and I noticed the master bedroom is a little warmer than the other areas of the apartment, I checked the Discharge Air temp out of the master bedroom vent and I was getting 56 degrees which is good (I think lol) but I noticed the airflow is very minimal compared to the other supply vents around the apartment, I went ahead and checked the filter and filter was good but I pulled the filter out and my god…the fins on the Evap Coils are in”

“I posted a week ago asking if my evaporator coil was dirty (I didn't know what it was supposed to look like). Thanks to advice here, it's much cleaner and blowing hard and cold. Thanks! Before and after submitted by /u/steeple_fun [link] [comments]”

“The AC people came out today and told me that my coolant was really low. They told me there must be a leak in the coil, and to track it down and find it would take $4,500. However they said they do not recommend that. They said I need a whole new unit. Whenever they told me their cheapest unit was $13,000 I wanted to cry. The guy didn't even recommend the $13,000 unit he recommended the $20,000. I didn't go with any of these options I just told them to recharge it because honestly that&#”

“Looking for some advice from homeowners who have dealt with Lennox HVAC warranties. I bought my house in 2024, and the HVAC system came with a 10-year warranty, provided the unit was registered. I made sure to register it. After about two years, the outdoor unit’s fan started making a loud/rattling noise. My husband took a look and diagnosed the motor and fan would likely need to be replaced. That’s when I learned that although the system has a 10-year warranty, after the first two years, it onl”

“Our upstairs guest bedroom turns into an absolute oven during the afternoon and my usual fan setup is just pushing around warm air at this point. I really want to avoid installing a permanent window unit if possible since the window frame is a bit awkward. Does anyone have experience using these for cooling down a single mid-sized space without breaking a bank or spiking the electric bill too much? thanks submitted by /u/Ambolaya_Daleea [link] [comments]”

“The ac cooled air is causing condensation to form and leak onto the dry wall below it, causing damage. What can I do to remediate this before patching the dry wall? submitted by /u/chilly-cool [link] [comments]”

submitted by /u/Wild-Loquat913 [link] [comments]

“I sprayed the evaporator coils with the Simple Green cleaner, but that didn’t seem to make a difference in the temperature. I had to open up a hole right before the horizontal slab evaporator coil to access the coils. Any suggestions? submitted by /u/moises8war [link] [comments]”

“There are six ducts coming from the same box. 2 of them are blowing "warm" air going to one side of the house. HVAC guy came yesterday and said it was low on freon, added 3lbs. Today it's the same problem. Been here 5 years and this problem started about a week ago. submitted by /u/beervirus2019 [link] [comments]”

“hey experts! The exposed wires and all on this outdoor heat hump give me anxiety. Does this install look okay? My HVAC guy says this is normal install. This is used throughout the year - even in Canadian winters. Let me know if you see any issues with this... submitted by /u/brukna [link] [comments]”

submitted by /u/Particular_Speed6749 [link] [comments]

“Hi, I'm looking for some advice on what to do here. I'm in Boston, so if anyone also knows a good HVAC tech who can properly diagnose this, I'd appreciate the recommendation. 6 weeks ago - HVAC was set to cool, but it suddenly started pushing out heat instead of AC. - I checked the breaker panel and found that the HVAC breaker had tripped. I tried resetting it, but it seemed stuck and I couldn't get it back into the ON position. - An HVAC tech came out and was able to reset the b”

“I recently moved into this townhouse where they have brand new carrier air conditioner units installed in the front of the house and it was working fine all summer and then we had a cold spell in Wisconsin where it dropped to the 50s and 60s so we just turned the air conditioner off and open the windows and then it got hot like the 75° for a couple of days so we closed all the windows and turned the air conditioner back on and it would not get the temperature to lower more than 1° I set the temp”

“I just moved into a new apartment and it’s pretty tiny, only about 200sq/ft. It has a new Midea 6,000 BTU U-Shaped Window unit in it. I know on paper that sounds like the perfect size, but since I moved in it seems like it struggles to keep the air cool. It blows non-stop to keep the air in my apartment at 70 even when it’s only been in the high 70’s outside and occasionally the low 80’s. If it’s blowing nonstop not to only cool my apartment 10 degrees I just can’t imagine it’ll be able to keep”

“Edit: I contacted another company to come check the unit out. I have had an hvac tech out two times both times they said the unit is running perfectly but it’s just at its max capacity. This is a 3 ton unit cooling about 1375 square ft. The unit fails to cool and is about 6°-8°F high of set temperature. Today it is 84° outside and I came home to find my house at 79° with the temperature set at 71 with the unit running. The unit runs near constantly but fails to ever reach set temperatures until”

“HVAC unit froze up yesterday. I called my HVAC guy and in trying to help me out (since he's alresdy done ~$550 of unrelated work for me this month) , he told me to check the evaporator coil and the filter. His words were something like, "It's possible you've got lint and pet hair on your evaporator coil. If so, you can probably get it off with your hands or a shop vac." I change my filter monthly-ish and this time, it had some pet hair on it but nothing too crazy but I chan”

“A couple of weeks ago my HVAC suddenly stopped working. In the sense that the air was blowing but it was not cool air. The outside unit fan was running but I couldn't hear the compressor. I turned off the thermostat and the entire unit and let it rest. After an hour or so I turned it back on and everything was normal. A few days ago I noticed water dripping from our window and went to look outside and noticed the water was coming from a drain in the gutter. I figured it had to be AC water an”

“my temp split is 22° but outdoor unit seems off. it’s a 410A system and H/O said at night it gets a little hot. i’m here for a tune up but what should i look for? also it’s a TXV submitted by /u/WholeEntrepreneur790 [link] [comments]”

“Question, have an HVAC unit I installed last July. Have a confusing problem that I’m trying to make sense of. Nothing really wrong with unit. Essentially I have an issue in the house where they are doing remediation for an unrelated water leak. They quarantined off a living room and dining room from the rest of the house where my main return duct is to the air handler. One of the quarantined sections they set up an air filter with a make shift air duct going to the return to bypass the affected”

“I have a 3 ton single stage ac installed in 2019 for a 1400 sqft townhome. Tenant is complaining that it’s not blowing cold enough upstairs. A vendor came in and reattached and sealed the ducts at the registers because there were gaps, and added freon. They took before and after airflow and temperature readings yet the tenant is not satisfied. Note, she has always been difficult. She’s suggesting that additional insulation is needed in the attic, and the ac needs to be replaced (as far as I know”

“I have a carrier VRF system in my house, about 4 years old - there is a single outdoor condenser, with 5 in-ceiling cassette units, each with it's own thermostat. In the last month I noticed it wasn't cooling very well, particularly in the living room which is larger and has higher ceilings. Last Friday the original installer came out to check it, said that it was low on freon so he added about 1.5 lbs of freon, and it cooled immediately. Last night I noticed it was not keeping up again,”

“ok first my ac went out and I vacuumed the outside drain line it started back working well then in the inside it started making a humming noise and it’s blowing out cool air but barely blowing I want to know what can I do to fix it submitted by /u/Oakboy90 [link] [comments]”

“I'm trying to diagnose an AC issue with my partner's Micra k12 1.4L . On a hot day it is more noticeable that when idling the A/C gets warmer. I've regassed it, it was low on gas, but issue persists. The compressor cycles approximately every 10 seconds. When the compressor runs the A/C gets colder, when it stops it gets slightly warmer, both when driving and at idle, but much more noticeable at idle. When idling and revving the air gets colder but still cycling between cold and sligh”

“My townhouse (~1200 sqft) has been significantly more humid than usual for the past few months. I‘ve been using a small dehumidifier in the meantime, and called a couple of places to get their take, which was that the evap coil has a few small leaks and should be replaced. My HVAC unit is out of warranty. The quote I got is ~$4200 for install, coil, and refrigerant. Is the evap coil likely the core issue causing humidity? Is that a reasonable quote? thanks! submitted by /u/Puzzled-Si”

“Received a message from my tenant. American Standard 3 ton about 4 or 5 years old. Location - in the lower southern states along the coast. During the day HVAC is kept at 76 At night Tenant turns it down to 74 Said they came home this evening around 10:00 PM and went to turn the thermostat down to 74. Noticed the thermostat was reading 79 and cool mode showing as it should. So at some point in the early evening the AC stopped cooling and even though it was set to 76, the temp rose to 79. They tu”

“Hi everyone! Looking for outside opinions before I spend more money. System Lennox ML14XC1-036, 3 ton, R-410A, installed 2020, manufactured 2019 (6 years old system) Lennox CHX35-48C-6F-1 evaporator, 4 ton cased coil, attic mounted 3,175 sq ft two story. Yes, 3 ton on 3,175 sq ft is undersized at roughly 1,050 sq ft per ton. It was specced that way from new. Factory charge 8 lb, estimated system charge 10 to 11 lb Home builder is Lennar Timeline Early Sept: system losing a full charge in about 2”

“Hello, I live in an apartment and have been having issues with AC. Is this a refrigerant leak? I’ve turned off the AC but it still has vapor coming out. submitted by /u/dannypesto [link] [comments]”

“Bottom line not sure what it is, I don’t know much about hvac units, has condensation/water forming around the fitting that runs into the system when the system is running. Our current temp outside is around the mid 60’s and the indoor unit is set on 70. Is it because the outside temp is so low or is my unit about to freeze up again? submitted by /u/Born_Revolution1081 [link] [comments]”

“A week ago my ac unit started blowing hot air. Turned it off and switched to my backup window ac units. Recently an ac company had came out to give me more refrigerant as it was so low it flipping a safety switch and the outside compressor wasn’t coming on. The same company came out and turned on the ac and it was cooling perfectly. So the tech couldn’t find an issue. He said no leak was detected. Now three hours later its back to throwing warm air. Any suggestions? submitted by /u/s”

“Hi all! I want to start by saying I live in Texas and this summer has been BRUTAL. And yes I've heard the thing about AC can only cool to within 20/30 degrees of the outside temp. But this summer was terrible for us. I'd have the AC set to 70 and it would be at 70 until around noon and then it slowly started to creep up. By 4/5pm it would be 78 degrees inside. I tried setting the AC higher to 75 even first thing in the morning when it would normally be able to keep it at 70, but all that”

“Just bought my first home not too familiar with hvac i tried testing which vents are return vents by using paper towel to see if it sucks it up (google said so) none of them seem to though itsa new hvac too at least the hvac itself im not sure if vents were touched up when previous owners got a new one submitted by /u/dovelol [link] [comments]”

“Quoted 7k to fix the duct work. Would this duct work cause the unit to not be cooling correctly? Also, could this be DiY? submitted by /u/aintsfan25 [link] [comments]”