Home HVAC Errors Are Hard to Diagnose Without a Tech

“I have a heil g96vtn that was installed last winter, it hasn’t had any issues until now. I just put in a new water heater, this involved upsizing gas lines and a new regulator. That would be the only thing that has changed. No issues with the water heater, but I get a 31.7 error code on the furnace. I don’t actually know if we had the error code before the gas line change or not, just turned it on for the first time this year. I do rack refrigeration, so I’m generally good at figuring things out”

“Background, I’m a service tech, installed this, has no problems heating or cooling when set on only that mode, but when switching to auto, it doesn’t seem to want to heat. At first I thought it was a temperature diff between heat and cool because I had it at 74/72 previously, generally they’re 3° diff so set it to 71 thinking it would work. Welp. It’s not. It’s an elite pro s1200 with an EIM because I’ve only got 3 wire here and can’t run new stat wire without cutting into my walls. (I tried pul”

“Hi. It's the first cold-ish day here, which means I throw open the windows and turn on the heat to my HVAC units. I have two units, all fairly basic Ruud/Rheem stuff. One unit did not turn on and gave me a 'pressure switch open' error code. I appear to have cleared blockage from the inducer to the switch - it was at the nipple on the inducer. The inducer now spins up and the heat now turns on, but I still get the 'pressure switch open' code at start. What should I do and/or c”

Does all communication between HA and the ecobee go through ecobee.com? I think yes but am not sure. Thanks

“In the process of buying a home and had our inspection was yesterday. The inspector says: "The typical temperature differential between the supply and return is not in the proper range. Thermometer readings indicate need for service." He was getting readings of 66°F at the supply and 71°F at the return. AC is 3yrs old. The selling agent says he did some research on the Lennox air conditioner and said: "That it is high efficiency so it’s not supposed to go below 68° unless it is fo”

“Hi , well no much time ago i replace my old control board for a new one but my main thermostat dons't work an the display show C1 https://preview.redd.it/not1rkrdluuh1.png?width=900&format=png&auto=webp&s=64d032a341b36f4b14caabd12a6d2a43b495ddce This is the new control board. https://preview.redd.it/m7aukkwiluuh1.png?width=1600&format=png&auto=webp&s=a171dc48becccd4bd614358c490b476a5b92f5f8 This is what the display shows. I read something about compatibility, but I do”

“Trying to get my ecobee essential to work but am having trouble even identifying how to troubleshoot this. This furnace is old and does not use the screw down terminals so my PEK wont work natively. My furnace is a International Comfort FSA2X2407A and the board it uses is a 1005-83-163A if that helps at all. i have attached pictures of the current set up. I have a C cable but I do not think its actually hooked up and my old thermostat did not use it. I cannot find it on the furnace side either.”

“Were you able to get this resolved? Mine doing the same thing. [re: Water Heater Thermostat Moves by Itself]”

“Is there a way recalibrate the ecobee premium thermostat. My readings are a lot different from the carrier thermostat I had The temperature on the thermostat is lower than what it is actually in the house and say the humidity is way higher than what my separate humidity and temperature gauge says it is in the house submitted by /u/Powerful-Tailor-1718 [link] [comments]”

“Is there anyone that could help me understand the wiring schematic for my smart thermostat? The company is useless!!! submitted by /u/Reasonable-Aerie9441 [link] [comments]”

“Using google home with 3 nest thermostats on 3 indepedant HVAC systems... the upstairs one has had the power breaker shut off to the compressor for about 2 months as we are waiting for cooler temps ( attic) to have that system replaced ( 30 years old)....this is the second time in a month that I have had this same warning with all 3 systems losing power 16 times in a 24 hour period. We have noticed no other power interruptions ..light blinks/internet wifi down/power off to electric clocks/ tv bl”

I recently switched thermostats a couple of months ago. This is how it was originally wired and this is the new wiring. I wanted to test the heat before it gets cold…

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

“TL;DR - Brand new first time home owner here, I know nothing about HVAC. Got a new heat pump and “emergency“ back up gas heater installed last week. Looking for a thermostat that works with this system configuration and doesn’t require an app or Internet access. We had a new heat pump with an “emergency“ gas back up system installed. The install came with a “free” Thermostat - it’s a Honeywell smart model (ElitePro S1200) that doesn’t work correctly unless it’s connected to both the internet and”

“Hey everyone, I have a carrier infinity unit that’s about 12 years old. Our AC hasn’t been since we don’t need it right now but I noticed there was a 73 error code. I couldn’t find a fix online, but does anyone know what a fix could be? Thank you! submitted by /u/UhOhPooTime [link] [comments]”

“Hi all, Im at wits end and I don't know where else to go for advice. Many HVACs don't do condos and Ive been trying to DIY and research on my own. Any help would be much much appreciated, thanks in advance. Apologies in advance as Im not good at HVAC or electrician jargon. Im in an older condo building with an old unilux fancoil. It was using a honeywell T6069B/C, I think its line voltage, 2/4 pipe, 120-240V. I couldn't use low voltage smart thermostats. So I purchased the MBTEK Apol”

“Got a new HVAC (Daikin) to replace my old Carrier Infinity. Right off the bat I am having issues with my two ElitePro S1200 thermostats (THX1200W7S, one for each zone): They connect just fine to my wifi ( EAP683 ), though they simply drop connection(!) at some point, usually after a few hours. The only way to get them to re-connect is to pluck them out of the wall, wait one minute, and then plug them back in, which is incredibly frustrating. I made a separate SSID just for them, so they are ...”

“Hi all. My thermostat locks up when I change the temperature one degree up. The thermostat sends a signal to the eim board and furnace. When the thermostat calls AUX2, the EIM sends 24V to AUX2/W3 and the furnace sees 24V on W2 but 0V on W1. The furnace only starts when W1 and W2 are jumped together. Everything is wired correctly. Ive double and triple checked all the thermostat settings (model ythx2000 honeywell). But sure what is wrong. submitted by /u/Own-Chef2275 [link] [co”

“I’ve been having this issue with this Honeywell thermostat for our upstairs thermostat only. when using the smart app for temperature control, the system works perfectly and will set any temperature I need and blow seemingly cool air. Lately, the touch screen on the physical thermostat will stop working and the time listed is off. when I take the faceplate off the wall and reconnect, it works sometimes and resets, while other times it says “power down thermostat for 1 hour”. The thermostat does”

“Hi HVAC wizards! Need help to configure this thermostat, I searched for hours couldn't find any manual It's stuck on sleeping mode and timers no idea where to find user guide Appreciate anyone can help me please Thanks submitted by /u/be5be5Man [link] [comments]”

“Can someone please help? I’m at a loss and have retried setup multiple times. I plugged the nest into usb to ensure the device works but can’t get power to work. My old stat was a Honeywell home and had batteries but still had a common wire, so I think it was still getting power? Attaching pic of old wiring and current wiring. submitted by /u/italianova [link] [comments]”

“Hello, I'm a newish homeowner and had a hisense heat pump with central air installed in Dec 2023. The fusible link for the backup heat blew out due to a clogged filter. The filter was replaced, but the fusible link is still out. How difficult is this to replace? It's high voltage correct? I know I'd turn off the breaker etc, but is it also difficult to find and remove the old and replace with the new? The HVAC company gave a pretty high quote so I could also shop around. submit”

“Google Nest Thermostat…. Yea, it only gets better… Two transformer system. Air handler works fine but boiler zone valve won’t open….yea….I open the stat and discover speaker wire on RH and W….2nd floor and the wall cavity is over a stairwell. Yup submitted by /u/AwwwComeOnLOU [link] [comments]”

“Noticed my thermostat stopped working and kind of stumped, I would appreciate any advice. Here’s some background: -Had a power outage yesterday that lasted 30 minutes while I was at work -Noticed today that the thermostat is not working, removed it and checked for voltage between A and B, 0V reading. Also verified no short between the thermostat wires. -the three fuses that I located are in good shape, and continuity checks good on each. -float switch in pan not contaminated, read closed 0 ohms”

A recent development in my house is that the fan stopped being able to run on its own. Ecobee thermostat was supposed to run it 5 minutes an hour. I noticed it…

“Good mornings HVAC folks. I have a Ruud/Rheem high efficiency furnace and when we tried to turn it on for the first time this morning, we got an error 57. A quick inspection of the vent outside showed it was completely blocked with a paper wasp nest and some pretty angry wasps. I didn't have time to deal with clearing that out this morning (it's now a problem for future u/Senior_Cheesecake155 ). BUT, once I do get it cleaned out, I'd like to take measures to prevent this from happeni”

“During the last days of last winter, woke up to find it very warm in the house. Thermostat was supposed to be set to 72 F but it was 80'ish. I'm thinking it's a stuck relay or contactor on the furnace control board, causing the furnace to ignore the thermostat's shutoff command. I just shut it off as it wasn't necessarily... but winter is just around the corner and I need to fix this. Anyone else deal with this problem? submitted by /u/Key_Lifeguard_8659 [link] &#”

“I can't figure out this thermostat for my life. I live in a condo rental and I'm trying to set the temperate to be 72°F all day. However, the A/C keeps turning on at the most specific time of the day and then the temperature drops to 65°F. For some reason, always at 10:38 AM the A/C will turn on and the temperature starts dropping unless I go and set it manually to be 72°F again. It turns on again later in the day but I don't remember which time exactly. How do I make this specific t”

“I recently experienced a problem with my electric heat pump where the house temperature exceeded the thermostat cooling setting by 3 degrees. The condenser was running but the air handler was not. I shut the unit off at the thermostat and went to bed. The next day after returning from a morning appointment I turned the system on via the thermostat and it has been working fine for almost a week. My question is, is there a smart thermostat available that could be programmed to handle that situatio”

“https://preview.redd.it/x2062jsp4wqh1.jpg?width=3064&format=pjpg&auto=webp&s=cba7cf593b30eee3dfaa1caa0fb2546daf89d722 I noticed our house was warm. Ecobee thermostat has a warning cooling wasn't kicking on C myhecked AC unit and the return line (circled in the picture) was covered in frost. I shut off cooling at the thermostat. Check the filter and it was dirty enough that it could have been the issue. Changed the filter. Now nothing will start up. Turning on the fan does nothing”

“Since I’m not allowed to post in the HVAC page as a technician, I’ll post it here. Got a call from a friends mother who was having issues. Found an E6 error code on a comfortaire 2headed ductless. Home has 3 condensers for multiple areas, 2/3 have surge protectors. The 1 that doesn’t have the surge protector on it, has a blown board (this is unit with E6 error & attached the photo), this units about 8 years old. We had some crazy thunderstorms here in the northeast when the unit started thro”

“Hey friends, My mother in laws York furnace was rapidly turning on and off every second, and the light for the code was strobing. Google said the board was shot. I had a tech out who recommended full furnace replacement to the tune of 7-8k (I'm in Detroit, and this sounds really high for a small bungalow furnace, but what do I know). Well my mother in law works at a grocery store and doesn't have the cash, and I figured since the furnace is shot, it couldn't hurt to try to fix it mys”

“There shouldn’t be anything wired into the frost stat. You’re grey and black should be from the room stat terminals only. Make sure you’re doing your 26:9 checks when removing that case on and off 😉”

“My thermostat has been intermittently shutting off and going completely blank, then coming back on its own later with no changes on my end. Already replaced the batteries. It didn't work immediately after replacing the batteries but next day the thermostat automatically turned on, then went blank again a few days later, so I know it's a battery issue or a bad thermostat? System info: Rheem air handler, model RXHF-17, sitting on top of a water heater in a closet. Based on some research, I”

“House came with the unit. Previous owners said they newer used it. Wall mounted thermostat is dead. Not used in a decade a least. I thought about having my HVAC contractor troubleshoot it but birds went in during spring and ripped a bunch off yellow insulation material and aluminum foil. Now I'm not sure if it's even safe to operate it again. I taped it shut but a lot came out. What would you guys do? I don't care much about ever using it. Just don't like things sitting not worki”

“Hello, My plumber and I have been trying to figure out this error. Fan runs fine, but we are getting into colder temps and it won't kick the heat on. My plumber has the thing taken apart and has been working on it for a few days. But can't seem to figure it out. He told me i might have to call one of the "lennox" guys lol. Hes a old school plumber but hes our commercial guy and does all the res furnaces too. Any ideas before i call the other guys on monday? submitted by &”

“power went out in my area for a couple hours last night. When it came back on, the outdoor condenser unit wouldn’t kick on. Everything on the thermostat looks fine (it’s in the Honeywell vision series), as in it is going into cooling mode. The blower is running fine, just not getting any cold air from the condenser obviously (it’s a run tru). We have tried turning the breaker off to the AC for a full hour before starting again. T he entire system was installed new in January of this year. There”

“Before I call a professional installer, I thought I’d ask here. Just moved into a brand new manufactured home. The home included a Nortek Furnace but not AC. We had a 3.5 ton American Standard condenser and coil installed right before we moved in. The home came with a Honeywell Thermostat. We’d like better control so we purchased the Ecobee Premium with sensors last weekend. However, when I sent photos of the existing wiring to ChatGPT, she said something about a heat pump as the O wire was curr”

“It's a commercial rooftop unit, heat pump, dual compressors, 2c/2h stages. Worked fine with old thermostat, but it was all busted up so I replaced it with a wifi unit to have app control over it. I done this many times before, but different HVAC units, this one is a particularly old, big unit. Posting photos of wiring on old venstar, and the jumpers on the back, and the new Honeywell wired up, (on the Honeywell, I moved the white wire to o/b after I took this photo). I'm lost, and now my”

“I have a trane system S9V2B080U4VSBBA I lost power and now that the power came back, I no longer get AC. I have power cycled the furnance / AC / ecobee. The control board shows: Zone1 Open (green) Y1 Compressor (orange) Fan (green) And yet neither the indoor or outdoor unit are responding. At the bottom window of the indoor unit says "IdL" Is there anything else I can try? submitted by /u/Aslimedr_wsnear [link] [comments]”

“I’ve just installed a hive thermostat after watching a few YouTube videos. When turning everything back on the heating works and the thermostat connects to the app but there’s no hot water. Nothing even registers from the boiler . I’ve double checked connections but can’t see anything obviously wrong. Hoping someone will prove me wrong! Thanks in advance for any pointers. submitted by /u/Moist-Instance-2052 [link] [comments]”

“This morning my Honeywell thermostat was flashing an error 53 code. Google said to check the outdoor wiring and this is what I found. I’m assuming an animal chewed on the white cord. Is this something I can fix myself? If so, how? There is no way I can afford to have a company come out right now 😩 submitted by /u/reader-rae [link] [comments]”

“Hi all, just looking for some answers before I call my landlord. I have been trying to figure out why this thing doesnt want to turn on the heat. The AC/cooling is working but not heating. Everytime I try to turn on the heating, I just hear a buzz sound. Trying to get ahead of it before the winter comes and dont want to get stuck without heating Thanks for all who will answer! PS. Cooling was running hence the 77°F temp and the 90°F temp is just me testing the heating submitted by /u”

“I have an old Trane system that works well. Recently the air blower runs almost constantly. The Ecobee smart thermostat shows no equipment running and the fan continues on. I disconnected the thermostat and the fan continues so I think I have it narrowed down to something in the main unit. Perhaps a bad switch. Any experience with this would be greatly appreciated. submitted by /u/Chemical-Ad-3461 [link] [comments]”

“My thermostat says no red wire connected (it is) and is showing Voc O.O2 V and Vin 0.02 v. i was told my fuse may have blown but I don’t see a fuse anywhere. It’s an old unit. What else could be causing the lack of power? submitted by /u/Low_Bluejay510 [link] [comments]”

“Here's another reported issue from Martin, via our emsesp.org email (unfortunately he has no GitHub account). The hc1 set summer mode entity doesn’t work on his IVT Geo 612C. Same with "winter". Only "auto" works. To test, select either “summer” on “winter” in the choice for the writable entity “hc1 set summer mode”, like call thermostat hc1.summersetmode summer which returns: Bad syntax. Check arguments. [command] Command summersetmode: summer failed (Error) He tested and confirmed the correct”

“A few months back I replaced my old iHeat AHS27-D with a Rheem RTEX-27kw. My old water heater I could have three hot showers at the same time. My new one, one shower will be scolding hot but if I turn on a tub spout or open several faucets, it gets an E5 error. The three 240V/40A circuits next to it all show 240V. But when I measure the incoming voltage on the water heater, only Bay 1 (the far right set of red and black) show 240 V. The other 2 sets show ZERO. So why is it going to an E5 error b”

“Our thermostat (Emerson Series 80 non-programmable) was working just earlier this morning, and after I turned the cooling off to clean the unit, I came back to find that the display was weird, half of the display segments were off and the rest of the display was fading. We tried replacing the batteries to no effect. I took the back panel off to look at the circuit board, saw nothing off about it from a glance, and when I placed the batteries back into it, the display started flashing like in the”

“in April, our thermostat failed. I called a company we used before and they installed a Honeywell 8000. everything seemed fine for the first few months. in July, our condo notified us the roof was getting done and all A/c units would be inspected and a group rate would be offered to have units replaced. we agreed to this as our unit was quite old. a different company replaced the indoor and exterior unit. ever since, then I’ve been receiving high humidity alerts. I away for the season from this”

“I have a honeywell pro series. I reset it trying to change some settings back to default. And now only hot air is blowing any quick fix. Orobably some setting I have to do submitted by /u/Dire_Wolfff1 [link] [comments]”

“I work in a lab and it is ALWAYS he wrong temperature. When it's hot outside, it's muggy and hot inside. Cold outside? Even colder indoors. Our maintenance contractor says our HVAC unit is just bad and can't keep up with the air turnover of the space, but I suspect it's more than that. Can someone take a look at this thermostat and let me know if it's wired correctly or if there is some way to test that it is? It's a bit more involved than my home thermostat otherwise I&#”

“Like the title says my thermostat quit working. I can manually turn on my blower motor and a/c unit but I can’t get the thermostat to control those things. It has new batteries in it. Any help would be appreciated. Thanks in advance. submitted by /u/spiraledout80 [link] [comments]”

“I’m wanting to switch back to the Honeywell thermostat from the Google Nest Thermostat E and I can’t find the picture of the wiring I took of it before installing it (my phone took a dump). Anyone offer some guidance? submitted by /u/Kongap [link] [comments]”

“Hi all, I recently just closed on a condo with this roof Magic Chef AC unit from the 80s that's still chugging along with no issue. I wanted to replace the honeywell thermostat with an Ecobee smart thermostat, but it looks like the B wire in the picture below is not providing any power. Does anyone know if the air handler should be located somewhere on the roof unit, so I can check if there is a common wire connection? The pictures were taken during the inspection, and I just wanted to make”

“HVAC was working fine, suddenly there was a power outage and the power was back on within 10 seconds. From then no AC is blowing and no power on Ecobee Thermostat. Any help? I checked 3 Amp fuse on the panel board and looks like it is all good. The purple one. submitted by /u/sstamara [link] [comments]”

“So my thermostat is connected to this smart hub called SmartRent for the apartment and whenever it detects moisture it just turns off the thermostat, there’s no power or anything connected to it. ChatGBT said I need to find the drain and take the moisture out of it, is it anywhere in this picture? It’s currently Labor Day weekend and it’s insanely hot inside submitted by /u/TheCatsButtholee [link] [comments]”

“Old thermostat starting spazing out and turning on and off whenever it wanted because the thermostat died..or something anyway i bought a new one, i have a heat pump w/emergency heat/cool im a low voltage tech by trade but electrical/hvac isnt my thing? can anyone dumb this down for me to the tune of put x-wire on y-post or did i buy the wrong one? submitted by /u/Tony2Wheel [link] [comments]”

“I replaced my own thermostat around 2022 via long-distance help from a friend via text. I remember replacing it in the summer, but I remember waking up feeling like I was in a sauna with the heat stuck on. It was like 97° or something inside. But, I feel like it wasn't unusual for the heat to be on, like it was already winter. I don't know. I do know I tried a few different models and finally got it fixed. I've been paranoid ever since and just randomly keep an eye on it when I walk”

“Hooked up new thermostat as shown and only things that work are the fan and heat but no ac. What did I do wrong here? There's a sixth wire seen at the bottom in the new picture that was not hooked up to anything. It was buried in the wall when I removed the old one. And I know there's a lot of copper showing but I promise you those wires are seated all the way in there. submitted by /u/LazyBrokerAz [link] [comments]”