HVAC Techs Battling System Failures

“The fan motor does not run. Ecm 142 by gentec. No longer available. The compressor does run. I am getting 24 volts between df2 on the defrost board (goes to c on the ecm) to y1 and df2 to Y2 on the ecm ( yellow and white). I am getting 240 v between l1 and l2 on ecm ( black and brown) . No power coming out of ecm module to fan. The red status light on the defrost board is indicating open circuit ( it flashes 5 times) so I don't know if the status light is indicating a problem that is prevent”

submitted by /u/taximan87 [link] [comments]

“I live in an apartment in Austin TX. Our system is 31 years old. Been corresponding daily with maintenance, who is apparently corresponding with the HVAC guy. Condenser motor went out a week ago, same-day we got the guy out to look and he determined he'll need to put in a universal motor because the system is old and he can't get the OEM motor. Now, when I google 'universal condenser motor' results show the part available at Lowe's & Home Depot. We've been waiting on”

“So this summer I got a side job to fix an AC. Showed up and coil was frozen. Went to run the furnace to thaw and was giving me a 3 flash error - pressure switch. Board wasn't sending power to the inducer so I replaced it with the kit 18110 (new board and ignitor). Same error. Ran through all the safetys and everything checked out (pressure switch open, limits closed). Visually inspected the wiring - checked out fine. By the time I put the old board back in I switched back to focus on the AC”

“I spent most of last heating season struggling with my heat cutting off on the coldest days. The first tech said it was a condenser and replaced that. The second tech said it was probably dust in the vacuum lines or switch, pulled some hoses and and declared everything fixed. I spent months learning about this York unit with a new(er) resideo board, how to read the lights and following steps I learned online. All before I knew about Reddit!! The problem only happens when the furnace is on for ex”

“Hello I believe there is something wrong with our fan portion of our HVAC. I am not the most handy and don't know all of the terminology, but I do sense there is an issue. I sounds like something wants to start. I can hear it struggling - for about a minute - then it will disengage/stop. This is the unit. We also use it as a "house fan" to just circulate air without the heat or A/C engaged. On the video you can hear the sound stop in the last few seconds. submitted by /”

“I have a York JHE36C5 AHU with the 9 tap 5 connector ECM motor. It runs at full speed regardless if the thermostat is calling for stage 1 or stage 2 cool. If I unplug the black heater wire from the 5th connector it slows down, and if I also unplug the Y2 yellow/stripe connector from the 4th connector it slows down further. I already verified the RDS is working and there is 0V between the red wires connected to 1 & 3 and common when the thermostat is calling for cool. There is also 0V between”

“My 20 year old A/C system is becoming a problem. The second floor compressor has been replaced 4 yrs ago and recently the capacitor and hard start. That fix lasted two days and now it’s dead. I’m considering 2 new units that run 208/230 voltage. With 115v air handlers. I have an upstairs on one unit and downstairs floor with partially finished basement on the other unit. Does this electrical panel look appropriate? submitted by /u/mwusa1 [link] [comments]”

“I have a 5-ton Trane system serving about 3,054 sq ft . Outdoor condenser: Trane 4TTR5060N1000AA Indoor furnace/blower: Trane S8V2D120M5PC with a variable-speed ECM blower The original blower motor failed after roughly 2 years and was replaced under warranty. After the replacement, static pressure was measured at approximately: Return side: -0.35 in. w.c. Supply side: +0.45 in. w.c. Total external static pressure: ~0.80 in. w.c. A second HVAC technician later got essentially the same total stati”

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

“Any way to fix a/c compressor don't stop ? Replace 3 time my relay. 3 time the presostat. (Sensor on the high side) My scan tool can not see any humidity in the live data. So i don't want to buy a new humidity sensor for nothing 2016 dodge challenger sxt submitted by /u/Big_Pickle_7954 [link] [comments]”

“I never did anything with AC units before and had no clue what I was looking at. Contactor was welded and wouldn’t release. Fan and compressor just kept running forever. Bought an exact model and it was pretty much plug and play. Everything works perfectly now submitted by /u/omegafrogpoop [link] [comments]”

“I have a York YCJD48S41S1 4 ton condenser. Say it is 80F and I turn the thermostat down to 76F. The AC kicks on and works fine, and the room eventually gets to 76F. The unit then cycles off as it has hit the setpoint, as expected. When the room warms up to 77F, the AC kicks back on, but only runs for maybe 15 seconds before the breaker trips if it has been a relatively quick (say 10-15 minutes on a hot day) restart. If, however, it's a cooler time of day and it takes a much longer time perio”

“Model #: 5SME39HL0252, 1/2 HP, 120/240 V, CN02. It's on a 21 year old high efficiency Lennox furnace + AC, so it has had a good life!!! Should I get a new blower motor, or start with just the module portion on the top? And is it as simple as unplugging and putting the new one in? Backstory: Furnace started making a weird noise (kind of random "thuds") that were echoing through the vents, I isolated it to the blower wheel. Upon inspection I could see it "stutter" every so”

“Assuming this is failed capacitor? Fan motor turns on for about a second before shutting off and doing a bit of google and my conclusion it is failed capacitor. submitted by /u/rememberwhoyouarex [link] [comments]”

“The ac unit fan was still working but the house was not cooling. The breaker kept tripping, so much so that ut wouldn't even stay in the on position. I opened the back panel and saw this capacitor. It looked bulging. I tested it with my multimeter for capacitance. No measurements what so ever. So it was bad. I replaced it with a similar one (guy at the ac supply store helped with that, i didn't guess). It was a duel one. So from the picture i put the red wire which you can see is the pow”

“Hello everyone - usually I can figure this stuff out but I’ve got an issue with my 25yo outside condenser unit I can’t seem to resolve. For reference - it’s an ICP CA5536VKD2 3 ton unit. Over the last couple years I’ve replaced the fan motor, fan blade, dual capacitor and most recently the contactor. The unit had a tiny leak this summer so it was charged to full with stop leak added. It’s now running great except for one annoying issue. It will only run for about 30-40 minutes then the fan cuts”

“I have a blower motor issue which I’m diagnosing a bad blower motor but just wanting to get advice. I have an ECM motor which I checked for 240V going into the motor and a 24V signal and I get both. Condenser comes on but furnace does not. Any advice or I’m good to change out the motor? submitted by /u/Alexxander10 [link] [comments]”

“What do you all have to say about swapping out a failed cfm on a fairly old unit but increasing the hp from 1/8 to 1/6 keeping the same voltage and rpm. I’ve had older techs tell me it’s fine as long as you match the rpm and voltage a little extra hp won’t hurt. Especially since the universal motors we carry only go down to 1/6hp. submitted by /u/Advanced-Mud6642 [link] [comments]”

“I have about a 10yo Frigidaire 4-ton split. Thinking to proactively replace cap/contactor/fan motor because those are the only condenser parts I've ever had fail. Pop open the unit and find out I have a 622656 ECM fan motor with two speeds in use. I'm an industrial controls guy so changing out and rewiring for a normal blower would be no issue for me. What say you all? Is replacing with a new ECM motor worth it or just go old school with a normal cap-start fan, same rpm&hp? Be a chea”

“Hey all, I have a Lennox XC-20 that is having the service urgent alert code 31: lost communication with device. The furnace works fine and it is not a thermostat issue. I have power at the condenser, but it is not running. I tested the inverter board with my multi meter and have determined that it has gone bad. I found the part # which is 16Y29 - but Lennox wants $3,800 for the board. Has anybody ever sent the inverter board out for repair instead of replacement? I see a few burn marks and think”

“AC went out in May. It is about 20 years old. I tested the fuses, one was blown. I checked the continuity of the condenser and short to ground. (Not experienced in this but I think I did it correctly from what I read online). My multimeter couldn't check capacitor. I changed out both fuses and the unit ran for about two months. I then changed both fuses again and decided to change out the capacitor. It ran for about another two months. This most recent time I just changed the fuses without t”

“Looking for some help from my HVAC friends or anyone with access to Carrier parts information. The indoor ECM blower motor has failed in my Carrier air handler. I’ve received a ballpark quote of approximately $3,353 for the motor, so I’m trying to identify the correct replacement and determine whether I can purchase the motor/module directly. Equipment information: • Carrier air handler: FV4CNF005T00ABAA • Model: FV4CNF005 • Serial: 0113A04296 • Original motor: Eon HD03 variable-speed ECM • ½ HP”

“Ac is tripping breaker , what’s broken? submitted by /u/sergio121692 [link] [comments]”

“Trying to figure out why out outdoor A/C unit stopped spinning, I replaced the capacitor but it's still not working. I can push the fan blade with a stick, I've tested the thermostat with a bypass to make sure that wasn't the issue. Could it be the contactor? submitted by /u/Sunikkaazu23 [link] [comments]”

“I am a new HVAC Installer who's own personal unit does not work properly. The compressor will turn on but the fan on the outdoor unit will not turn on. The blades spin freely if pushed with a stick but it will not catch and stay moving. I replaced the capacitor and it still does not work. I am thinking it may be the fan motor? Or a wire issue. Note: there is a wire coming from the attic to the unit but it is disconnected (I think it got hit with a weed Wacker). It looks like the wire belongs”

“Came across an ecm blower motor today that kicked my ass. Lennox system and universal drop in. Thought I maybe could just attempt to wire it up and splice some cables. Nah, no chance. Now customer says he’s gonna call another company. In the 3-4 years I’ve done this, this is my first one and boy was it a learning experience. Screw universal stuff, it’s never worth it. What would yall charge for a Lennox 3/4 hp ecm motor swap. Motor alone is $800-1200 depending on where you order it from. s”

“New R454B trane condenser Pulled vacuum to 190 microns Hit 10 degrees of sub cooling Yes it’s on a 454b evaporator coil. This was 4-5 hours after startup Also installed a micro air soft start. Anyone else having these issues with the compressor being this loud on 454?? Also flushed out old line set with rx11 flush submitted by /u/hahahahajej [link] [comments]”

“I'm having troubles with my condenser. Woke the past weekend with my unit not working. Had a company come out and threw the parts cannon at the condenser. New fan motor, contact, capacitor. The unit is back up and running and blowing cold air. My problem is after a couple of hours running the condenser fan just quits running, never throwing a breaker. When its happening I still have 240v and no excessive amp draw. The company said there's nothing from keeping this running fullime as ther”

“I am in a condo with two AC systems for my unit, which are both on the rooftop. About 6 weeks ago, the AC in the top floor stopped blowing cold, and a company diagnosed it as a condenser coil springing a large leak that required replacement of the coil or the entire unit. They showed us video evidence of the leak on the condenser coil. The recommendation from the company was to replace the unit, but we decided to try to go with the short-term/cheaper fix for personal reasons. Included in the pur”

“Our 20ish year old ac is likely reaching end of life. It's an r-22 system that's drawing within 20% of its max amps and when it's hot (~105) it will shut down for a bit until it cools off. When it runs, it runs great though. This mostly happens when I drop the temp in the evening from 77->74 degrees. I'm managing it now by decreasing the temps in smaller steps so it doesn't run as long. Sooo..... is it time? submitted by /u/Radixx [link] [comments]”

“I had to replace supply fan #1 since it failed and was tripping the breaker. After I installed the new motor, both supply fans ran for a short period of time, but when I went to test cooling in symbio it would not let the compressors/condenser fan motors come on. Swapped out the phase monitor which failed also. Trane said to cut out all the plugs to the fan and wire nut everything together. Both my fans are receiving proper 3 phase power, and 4.7-4.8v dc from the modbus. Trane also confirmed wit”

“Long story short, our AC unit kicks on, but the fan inside barely spins, and then shuts off after about a minute. I've tried manually spinning the blade, but it eventually slows down and shuts off. I've got the multimeter set like this, I'm touching the black to 'C', and the red to 'Fan', but the screen doesn't change from 'OL'. Does the same thing if I move the red to 'Herm'. submitted by /u/weiserca [link] [comments]”

“Hi, it's probably premature for me to post here because I only heard from my friend, I haven't seen it, I don't know what the model is, but he claims it will start and works but it takes a few tries (as many as 10) to start, he mentions a surge in power (lights will dim). What should I look for first, please? It doesn't SOUND bad, like another I've dealt with had a bad capacitor and it sounded rough when it ran, this one doesn't. Thanks! submitted by /u/strume”

“Last night our ac went out. I pulled the panel off and pushed the contact plunger and it seems the condenser starts up the the fan doesn’t spin. I just recently got a new fan installed a couple months ago and it still spins when pushed with a screw driver, so I figure I’ll check out the capacitor. What has me confused is that the terminal for the condenser has a wire to it, also the herm has a wire to it but there’s no wires on the F capacitor terminal. Would there be another capacitor for the f”

“Furnace model: GMVC961005CNBA Blower motor model: M055PWCVA-0328 Hey all, I’m trying to figure out if it’s a bad board or bad motor. I’ve verified the motor is receiving 120V on the main power harness. I don’t know what voltages I should be measuring on the other four-wire harness. I believe this board sends only DCV signals through the harness. The harness wires are labeled GND, TX, RX, and VDD. I’ve attached photos of the wiring diagram and the board, any help is appreciated. submitted b”

“One blade on my condenser fan decided to exit the chat into the condenser. Pretty sure the whole unit is phucked submitted by /u/Goobalicious2k [link] [comments]”

“I just want to put this out there and see maybe what other professionals may think. I had a new HVAC system installed in May 2023 International Comfort Products (ICP) PGD4 Model: PGD424040K000K1 I had paid for extended maintenance agreement which covers 2 visits per year for 10 visits total (5 years) When they came out in 2025 they said my compressor did not sound good. They said it was due to short cycling and there was ants in there causing the short cycling. Since it was under warranty it was”

“We have the following unit. The outside fan no longer runs. Doing some research it seems like it could be a fuse or transformer. Not sure where they are located. Could use some assistance. I did see one "E" fuse and it looked fine. submitted by /u/chocmatic [link] [comments]”

“Do I need to have a surge protector for my HVAC system in my attic? I already have one for my outside condenser unit. submitted by /u/Hot-Sock-9736 [link] [comments]”

“Downstairs ac is blowing warm air through the vents. Sounds like the fan motor is working. I added a video, the ac with the brown on the tube is the faulty one and the second ac is the functional one. Any help would be greatly appreciated. submitted by /u/MaximumEffective1127 [link] [comments]”

“Background info: started having issues last Sunday where late afternoon for a few hours our condenser would stop working and wouldn’t blow cool air. HVAC guy came out, said they’ll have to order the part and replace. That was Tuesday and we’ve been running a window unit since. It’s 107° today and no cooldown in sight. Can I plug safely plug this back in and run the unit until they can get back out and replace the part? submitted by /u/phallophilic [link] [comments]”

“I got an old reach in cooler condensing unit problem racking my brain. So the unit is a tecumseh single phase 208v 4 ton 404A condensing unit serving a reach in bar fridge. Got a call that the fridge is warm. Got to the roof and immediately saw that the potential relay terminal 5 was fried. I looked a little further and found d the start capacitor had 0 mfd as well. I figured maybe the compressor was shorted or just not working right, but I had proper resistance readings across all three winding”

“Help I wired up a new thermostat now my outside condenser will not power on? Is this correct submitted by /u/Parking_Natural_5592 [link] [comments]”

“Amana/Goodman condenser unit. It started out as the condenser fan would sometimes not come on when it’s supposed to, then started becoming more frequent. It progressed to it being sluggish to start where I would turn the blades with a stick and it would run fine although a bit noisy. Afaik, everything else works fine. The compressor always starts and the condenser becomes hot, cool air comes out of vents, just the condenser fan doesn’t come on. I’m getting 120vac at the brown wire feeding the fa”

“Today I discovered that my AC condenser fan is inoperable. I did not have the items I needed on hand before leaving for work to test/swap capacitors to see if that would be my issue. I will be able to all of this after work so in the meantime I’m trying to plan ahead. The system is a Rheem heat pump with an indoor handler and outside condenser unit. The condenser kicks on but the fan on top does not. The fan is a Genteq 5KCP39KF Z632S according to the label that I can see. It’s 1/5HP, 810 RPM. I”

“Hello. Any advice is appreciated. I had a Broad-ocean KMSAHO12CO3 ecm blower motor hd46mq128 115-120v that went bad (The reason why I think it's bad is because the furnace control board did not give any error codes and when I did a voltage test, there was power being sent to the motor, but I would never start. Although it does start once when the attic isn't hot, but as soon as it starts to heat up in there no more fans. Outside A/C works just fine). The new motor is a CLIMATEK MOT99-921”

“Good Morning, Recently my apartment was doing work on the condenser outside my bedroom window Because they stopped working. They have been in and out for days, and I believe they said they were fixed. However even since the repair was done 1 out of the 3 units is super loud with a slight uneven buzz to it, it also never turns off. Since it’s right next to my bedroom window it has been keeping me up at night so last night I went to go check it just to see if anything was noticeable wrong with it.”

“I recently replaced both the capacitor and the contactor due to the same problem. The issue got slightly better afterwards but we still have the issue of the condenser not always kicking on when the house AC does. I have to come outside and tap on it for it to start. There has to be some kind of electrical component not making good contact I assume but I am coming here for advice on what to do. About 50% of the time it turns on without any issues. submitted by /u/sageathor [link] &#3”

“Unit just had its 1st stage evap coil replaced, had a lot of leaks. 2nd stage will turn on, then the 1st stage will turn off again. I’m suspecting the compressor is going off on overload since it’s reaching 89C/190f and no error codes are being displayed. I’ve phoned tech support but I’m waiting for them to actually call me back. submitted by /u/MrDingDingFTW [link] [comments]”

“Hi everyone, I have an outside Central Air system tied into my furnace. I heard it making some strange noises, then turned off. I checked my breaker box and the breaker labeled "AC" is popped. If I turn the breaker on, the motor moans and the breaker immediately pops again. Furnace filter is fine. I bought this house a few years ago, and hired a company to do some basic maintenance on the AC unit as the condensate line appeared to be minorly clogged a few weeks ago. To my surprise he t”

“Sorry for my rudimentary question but it’s for a family friend and I’m in a predominantly gas furnace market. I’m measuring 0.2 ohms between N.O and COM on the relay. Blower motor runs constantly as well. We’re looking at a bad relay board is that correct? submitted by /u/logdognotnice [link] [comments]”

“My ac has been on/off short cycling for 15 seconds but only sometimes. it started during the heatwaves and i assumed it was just due to the fact it was so god awful hot outside but atleast once everyday, the unit outside tries to start up, runs for 15 seconds, then shuts off while the inside fan blows just regular air for a few minutes before shutting off as well. for some reason it also seems to work better if the temperature is set colder than i actually want but i dont know if thats a coincid”

“Looking for advice on what my options are. This is 2008 system with a Trane xl16i condenser and a xv95 furnace. The compressor on the condenser just died, it has a short to ground. I’m located in the CO front range. Here are quotes I have so far: - Replace compressor: $4,000 - New outdoor AC unit & Coil: $7,500 - Bosch IDS Ultra Heat Pump integrated with existing xv95: $8,500 - Bosch IDS Ultra Heat Pump with new GHP97 furnace: $13,500 On the heat pump options I am sticking with dual fuel as”

submitted by /u/TechGuy115 [link] [comments]

“I’ve been having ongoing HVAC issues since the winter. Management keeps sending the same technicians, but they just replace the refrigerant/gas, which only fixes the problem temporarily. In the winter, the apartment wouldn’t heat properly, and the air coming from the vents was the same temperature or colder than the thermostat reading. Now in the summer, the thermostat is set to 72°F, but the air coming from the vents is only getting down to about 69°F. The tech says there’s no leak because the”

“Outside motor is buzzing, fan is barely moving. I guess it's the capacitor. I will call a technician. See video . submitted by /u/twocentsrworth [link] [comments]”

“The original capacitor is so rusted that I couldn't see any word so I just took a picture and replaced with a new one, based on some wiring help search. The condenser was running but no cold air coming indoor. An hour later, condenser stopped running. Did I wire wrong? The first one is the original and the second one is the new connection. I did Purple - c Brown - fan Oranges - herm submitted by /u/iwillflyaway1234 [link] [comments]”

“I turned my AC off when I went out on a week vacation. It was working fine before, but I came home and it's not cooling at all. I called an HVAC guy, and he said that the fan was spinning in the wrong direction. He put that leaf on there, and showed that it was sucking in instead of blowing out. Then he said that the capacitor was good (a bad one might explain it spending the wrong way), so the motor is probably failed. And then he tested the compressor and said that it's dead so I would”