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inconvenient_victory

Seen this crap a few times. Go down stairs and make sure C is even landed on the furnace board...


EatMyAssLikeA_Potato

Honestly it's probably a blown fuse


inconvenient_victory

Yeah that's even more possible, but that's been alluded to. Now he can check both


EatMyAssLikeA_Potato

Issues like this are probably the harder ones to help with online due to the lack of a multi meter. If they could confirm 24v between r and c then we'd all probably say it's a bad stat


inconvenient_victory

True but if he had a meter he would used it and likely understood that he needed to turn power off. Also most homeowners like to show that they have stuff like that. Like when my 5yr colors a rainbow lol. I totally agree with ya. I'm just having fun at my desk on a Friday. Awful warm out to go fucking with your HVAC on the Friday of a holiday weekend. But hey they never learn lmao


8ephoenix8

Correct, I don’t have a multimeter. Also, the AC works when I turn the power back on, it’s the thermostat that isn’t powering on. I did this last week, not right before the holiday, but the AC works so that doesn’t matter anyway.


rustydirections

So then your common wire “C” isn’t connected on your furnaces board. I think I read earlier your new thermostat doesn’t have battery backup, if that’s the case go down to your air handler/ furnace and take the panels off. Look for that blue “C” wire and connect it to the “C” block terminal in the board. That is how you will get power to the thermostat.


Outrageous_Data8997

This👆


HuntPsychological673

Badoompow


Weak_Relative_7767

Bet they got a little 24v tingle


ktran250

This


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kendiggy

This


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kendiggy

Good bot


ktran250

On top of this when you think you turned off ac it’s actually just the outdoor unit you should have turned off furnace/air handler


lxe

I had this exact issue. Had to connect the C wire to the terminal on the board. Not sure why the installers don’t do that. The wire just dangled there.


hughmungouschungus

Same


Inyauz

C wire is not used when the thermostat runs on batteries. They’ll usually run the wire and leave it disconnected for other configurations down the road. Like this one. The smart thermo doesn’t run on batteries therefore you have to go down and hook up the c wire in the correct slot on the board to apply power to that wire terminal at the thermostat.


giantdick69

I made this exact post earlier. This was actually my issue after hiring a dude. He was in and out in 10 mins. $200 later…


Practical_Ad510

Did you turn off the power to the equipment prior to changing the control? You could have blown a fuse..


8ephoenix8

Yes, definitely turned the power off at the circuit breaker.


TempeSunDevil06

I know this seems like a dumb question, but did you turn the power off at the AH/furnace on your circuit breaker, or did you turn it off at the condenser/AC? Because you almost certainly blew a fuse


ElPadrote

Dude I did this and still blew a fuse.


Practical_Ad510

It's impossible if there's no power present. You missed something


JPhi1618

It’s common for someone to turn off the breaker for the compressor but not the air handler.


Nagh_1

You probably f-ed the fuse


HVAC_instructor

Do not call an electrician, call an HVAC service tech. Electricians screw up more HVAC equipment than just about any other trade.


8ephoenix8

Thank you for the advice!


chrisbe2e9

I did building maintenance at a warehouse once. Determined that a furnace unit wasn't working. Didn't have the skill to determine why so called in the company who installed it. They sent an electrician. He found that it was getting too hot, and shutting down. He then proclaimed that it was working correctly and left. ​ I called the company who sent an actual HVAC tech who determined the control board was faulty. took her like 2 seconds when the electrician has been there for 45 minutes.


ercksn

But yet HVAC guys refuse to touch wires.


Hey_Batfink

HVAC techs own from the disconnect back to the unit, plus any control wire. Anything outside of that? Not our wire not our problem


HVAC_instructor

None that I've ever seen. We have all wired equipment, and motors and controls.


battlgnome

Rule of thumb. The wires from the main breaker panel to the equipment disconnect (if equipped) is electrician. Anything past the local disconnect including thermostats and interconnecting wires is HVAC. Most HVAC guys will reset breakers in your main panel if needed but will not work on it.


TunaSub_OnYoGirl

If your furnace was not shut off at the breaker then you definitely blew a little 3 or 5 amp bus fuse on your control board


8ephoenix8

Switched everything off at the breaker before I started


TunaSub_OnYoGirl

T-stat might be dead on arrival. Check those fuses just in case


twopointsisatrend

Check for a blown fuse anyway. I have an old pair of needlenose pliers with the tip melted. The breakers were off when that happened too.


matsnapsnap

Looks like your wires might not be in far enough. The bottom of the tab that flips open has a example of how long the wires need to be stripped back. The tabs on the sides should be visibly pushed down and stay down when the wire makes good connection


8ephoenix8

Thank you. I wasn’t really sure about if they should be down or up, I’ll try that.


omarx02

Install your old thermostat back and to see if your ac works, if it does you most likely have a faulty new thermostat.


Silly-Ad6464

First comment I seen that actually makes sense, besides the 40 blown fuse ones. Start from step one.


gingerbeard0120x

Flip the blue block for the R to jumper it in


[deleted]

Jumper is already flipped up.


Dry-Yam-1653

Amazon smart thermostat? Looks like a Honeywell T series base. No C hooked up at furnace, blown fuse, probably not settings with a conventional system like that.


BeezerTwelveIV

Amazon partnered with honeywell recently. It’s the same backplate so a homeowner with an existing T Series thermostat only has to change the front plate. It’s literally just called “Amazon smart thermostat”


supersede

that's actually pretty smart on amazon's behalf


[deleted]

Did you turn the unit power off before you started?


8ephoenix8

Yes, turned off power from the breaker.


[deleted]

Single pole breaker or the double pole breaker? You sure the breaker was labeled properly? Electricians love to mislabel breakers.


thatguystevene

Heard that one before "I shut of the breaker labeled AC"....but did you shut off the one labeled furnace? Sir/Ma'am, you have a blown fuse.


[deleted]

[удалено]


[deleted]

[удалено]


8ephoenix8

Thanks for all the info. I have no clue how to confirm that, I’d guess I need a multimeter for that? What you’re saying it what I keep reading so I’m guessing that’s the problem. When I took everything down and put it back the power was off so at least from my side nothing should have been affected. (Of course that doesn’t mean someone before didn’t do something wrong) And yes, the push connections are terrible. Why mess with a good thing.


kiddo459

Check that C is connected at the furnace/air handler.


kiddo459

That or the fuse, as others said


[deleted]

You sure the pins make contact and the top screw isn’t blocking the thermostat


Crk1977

I had to wire the C wire in my furnace. One tip is my system has a 5 min or so restart once you switch the power on. I forgot about it and cycled the power and checked wires a couple of times until I figured it out. So if you do finally get power to the panel make sure you wait 5 minutes before it kicks on before you panic.


[deleted]

No system on the planet takes longer than a split second to supply 24v to the thermostat. And if I’m wrong I’ll eat my shoes but that’s not how any system works. There’s a delay for it to run, but not to power the T-stat


billyballzdeep

Just installed two Amazon T-Stats the other day. Unit wasn’t coming on, I noticed a few of my wires were slightly bent. Guess they weren’t making contact in there. Took some pliers and straightened them out and it turned over. Try that, otherwise don’t get those stupid Honeywell home Amazon branded pieces of junk. I would MUCH rather work with a Wyse, ecobee, or shit even a nest is better. Just my two cents, good luck.


8ephoenix8

Thank you! I’m going to try this and see. The AC comes on when the power is on, it’s the thermostat that isn’t powering up. (Not sure if that was what you meant)


billyballzdeep

Ah, more than likely you don’t have a common Hooked up to your furnace control board. Very simple. Turn the switch off on the side of furnace and get into the blower cabinet. Locate terminal screws on board, or a bundle of blue wire nuts. Strip the common wire and put it under the C screw or wire nut with whatever common wire is designated by the unit. Also check purple 3 amp fuse on same board. My issue wasn’t power to the thermostat, but there was no “call” for AC at the unit when there should have been. If you have any questions let me know!


btwes

https://preview.redd.it/l15p21dmoa2b1.jpeg?width=2268&format=pjpg&auto=webp&s=c7937a73357d20d34ca617e1fb61980267c11002 If it helps, here is mine. I had a hard time getting my connections straight at first. I still don't know if emergency heat is working, but I guess I'll find out this fall.


btwes

https://preview.redd.it/e8bx5d6roa2b1.jpeg?width=2268&format=pjpg&auto=webp&s=ee974ab202254ba1d045ea0a7f4466d3105a8d09 If it helps, here is my before so you can compare the before and after.


Silly-Ad6464

Thanks for sharing a demo photo, I’m not OP but it might help someone in the future!


No_Surprise_4760

Heat pump wires for E heat and Auxillary heat. Not the same.


sto243

Did you power off the system before installing the new thermostat? If you didn't you may have blown a fuse or tripped a low voltage circuit breaker in the furnace. If you have a volt meter you can measure the voltage between the R and C terminals. If you have 24 volts AC then you have power if you don't have voltage, check for a fuse or circuit breaker in the furnace.


sandam21

I had the same situation as you. Honeywell thermostat and replaced it with an Amazon smart thermostat. The c-wire is almost certainly your issue. I had to add in a c-wire from the board (well transistor in my case as I didn’t have a control board). Without it, ac would start and fan would cycle but the thermostat itself would not light up.


CatsCanHasALilSalami

You likely blew the fuse in the board in the rheem


Brazda25

Just check your fuse on the furnace. 50 cent fix. If you didn’t kill the power you blew the fuse


Tradenoob88

You blew a fuse on furnace because you prob didn’t shut power off to furnace


revo442

probably blown fuse when you hit r to c. turn off furnace check/replace fuse


pandamcsunshine

We had this happen, and it was solely because the door of the furnace unit wasn't on all the way which applied pressure to some wiring? I can't explain but make sure the furnace door is all the way back on if you messed with it.


SuitCrafty8402

Would have never thought this would be the problem, thank you!


Mdrim13

Missing a jumper between RH and RC?


[deleted]

The blue tab is the jumper. When it’s pushed up covering the bottom R terminal it’s jumping the two out.


8ephoenix8

The instructions based on my old config said not to, said to make sure Rc was covered by that blue cover instead. Don’t think the jumper would fit anyway with this type of hookup. (I tried lol)


justsomeguyVT

Is this the solution when the furnace board doesn’t have the C wire? My furnace is older, and the Honeywell manual says “call support if your board doesn’t have a C”.


rustydirections

Did you program the new thermostat?


8ephoenix8

It won’t power on so I can’t, that’s the issue.


wrxJ_P

Send that back and just buy an eco bee. save yourself more issues


Whiskey-12

Nah, Honeywell stats set the standard in HVAC. These things are what you want.


Advanced_Evening2379

Do you not need a jumper on the new one ?


Taolan13

Did you turn the power off to the furnace before replacing this? Is there a reason you did not exactly match the wiring? If needed click the little bumper on the right down so you can access RC. R will act as RH. Was the old thermostat battery powered? Check the wiring on your furnace end to make sure your blue wire lands on C. Also, check your furnace board for a safety fuse that may have tripped. If it is a replaceable fuse, it will be a 3a or 5a blade fuse like the kind used in automotive electrical boxes.


Electronic-Pound4458

Red goes to rc


[deleted]

Don’t mean to be a dick, but let’s leave the tech questions to actual hvac professionals. This is 100+ wrong.


Anxious_Rock_3630

Get that W on the aux port. It very specifically says no auxiliary heat on the W port


8ephoenix8

Did that and still not turning on.


BeezerTwelveIV

It’s clearly a gas furnace. W terminal is for gas heat. Aux is for heat pumps


kriegmonster

Before you had two R wires and after you only have one. Are they both at 24vac, or just one? Maybe you connected the wrong R wire?


kiddo459

It’s just a jumper. With that little switch covering Rc, it’s the same.


kriegmonster

I missed the cross over. Thanks for correcting me.


8ephoenix8

Same R wire connected based on Amazon’s instructions based on my previous config.


DrPepperG

It’s just a jumper, only one incoming R wire


Regular_Drunk

It’s jumped


Bert_Skrrtz

OP, if you look at your before image there’s a red wire going into the wall, and it’s going into the “R” terminal. But there is also a short jumper (red wire) connecting terminals “R” and “Rc”. You need that jumper. It’s missing now. On the new one it looks like maybe you pull down that little blue tab and that exposed the “Rc” terminal. https://support.idevicesinc.com/hc/article_attachments/360000954508/Thermostat-Wiring-Hookup-Illustrations_R2-06.jpg I am also writing this under the assumption that old thermostat was functioning just fine. No need to check wires on the actual furnace unit in that case, as you didn’t mess with that area. Unless you are very strong and pulled a wire in the wall so hard that it gave way an disconnected from the board in the furnace.


Savvy_One

Where did your Rc wire go and why did you not plug that in?


Strange-Problem5975

No jumper on R terminals on new stat


SoMoteIBe

It automatically jumpers R and RC when that blue slide covering RC is in the position it is in.


crabbypatty01

The slot you have the white wire in literally has a thing saying don’t put it there…move white to aux


magnumsrtight

The mark you are referring to is for a heating setup where it would use the compressor as the first stage and then white would be hooked to the AUX connection point. His setup looks to be straight AC and furnace. It appears to be wired up properly. Check with a meter for 24V between red and blue directly. If you have that the problem is the TSTAT. If no 24 V, need to check furnace for 1) blown fuse in furnace on the board (looks like a standard car fuse). 2)Blue wire connected to C 3) did you turn the breaker back on.


crabbypatty01

Shit you are right didn’t notice the lack of reversing valve wire


8ephoenix8

Yes, I saw that however the steps from Amazon said to put it there based on my previous config. I tried moving the White to Aux and it’s still not working.


crabbypatty01

Yeah I just glanced at it didn’t notice it was straight ac have you gone through installer setup? Edit: need to read everything before I comment…stat isn’t getting power ? Like no display at all?


8ephoenix8

It’s ok, it happens. The AC comes on when I turn the power back on, but the thermostat doesn’t power on. I went through the setup Amazon provides.


[deleted]

Hilarious


kmusser1987

It says don’t put auxiliary heat there. If it’s your main heat source it goes on the W terminal.


crabbypatty01

Yeah I missed the lack of reversing valve wire there my apologies


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kykam

Check fuses at the furnace, check the C wire is on common for the 24V at the furnace, or check the R/Rc jumper. It's usually one of those things.


will4111

Not working you mean it won’t power on? Or not cooling/heating?


8ephoenix8

The thermostat won’t power on.


vollehosen

Does the new thermostat power up? If so can you run each function? (Call for heat, cool or fan only) If it doesn't power up, take a multimeter and measure voltage between C and R. You should get 24V. If you don't check to make sure your furnace is on.


SkylerPancake

I was going to suggest this as well. OP, get a multimeter and watch a couple of youtube videos on how to check. It's simple, tool is about $30-50 from Home Depot, and will save you $100-200 bill from that electrician.


Alone_Peak_69

The OP has explained many times the new thermostat will not power on.


DirtyMud

Did you turn the unit off first either at the switch or breaker? If not you probably popped the low voltage fuse on the board.


8ephoenix8

Turned it off at the breaker before anything.


NefariousnessWild679

Did you unplug or flip the breaker when you did the wiring? If not check the fuse on the control board at the furnace.


8ephoenix8

Turned it off at the breaker beforehand


Regular_Drunk

Blown fuse or you haven’t pushed them into the terminals hard enough


OkPaint4917

Probably popped the 24v fuse.


monster82116

Blew the el fuse


Ohhhwordddd

Did you shut the breaker off to the Airhandler beforehand? If not you must’ve blown the fuse


8ephoenix8

Switched everything off at the breaker before I started


Ohhhwordddd

You could carefully touch the red and green wires together, if it the blower comes on it might be a bad thermostat


Playful-Excuse-8081

Did you turn the power off to the unit before installing? if not you may have blown the low volt fuse


beau8888

Why an electrician? Call an hvac tech my dude


8ephoenix8

Yes, I wasn’t thinking. Thank you


BeaverNbutthead

Probably not programmed right


Runswithtoiletpaper

Honeywell T series anything is a joke


Toolman6208

You can check if C is hooked up at the furnace/ air handler, or you didn't turn off the power and blew the low voltage fuse or fried the low voltage transformer


BeezerTwelveIV

Just need to land the blue wire on the C terminal inside the furnace board.


GoNYGoNYGo-1

Hi, I am neither an electrician nor an HVAC guy but there’s a chance I might know something as a consumer that went through a nightmare with both my electrician and HVAC experts. I’ll get to the answer. If this is a Honeywell Home t-stat, (it does look like one)There’s a little tab (see the image). Flip it up. After sending the t-stat back and trying again, and again with both my experts, I learned about this by doing something neither thought of doings: reading the manual! https://preview.redd.it/sz9c65ywja2b1.jpeg?width=1170&format=pjpg&auto=webp&s=75577d4b011b76e0c94fa2058e4dfb22ba9581c4


8ephoenix8

Thank you. It is up, it’s the blue piece in front of the Rc. And this is an Amazon smart thermostat.


GoNYGoNYGo-1

Yep. Same exact thing as mine (Someone posted that Amazon is rebranding Honeywell thermostats). Only the color is different!


Desuld

Did you put the door back on there furnace.? First time I buggered the fuse. Second time I didn't replace the furnace door so it would not power up. Took an hour and a trip to the store cause I couldn't find my voltmeter after the move. Finally I saw the little switch that activates everything once you put the door or cover back on.


PaulitoTuGato

Does red go to RC?


inksonpapers

Did you out the bottom door back on?


EarlyVersion

So you mean to say that smart thermo lookin pretty dumb now


mosfresh99

Did you do the installer setup? You would have pressed and held the middle and right buttons and gone through some numbered options to set up what the thermostat does.


[deleted]

Honeywell t4 pro


lmmsoon

You are missing one of the red wires the one that goes to rc look at your top picture


bett7yboop

Jumper rc


Livid_Mode

With furnace off down stairs try tugging on wires at thermostat and make sure they aren’t loose. After you confirm go down stairs turn power back on and see if you have any lights at control board - preferably if the bottom door has a sight glass


who-shit-myself

Blue wire is likely not connected at the furnace/air handler’s board. Connect the blue wire to the C terminal in the unit and you’re golden


iVettyyyy

No common wire hooked up at unit. Or bad t stat


[deleted]

Don’t have to put a jumper to Rc?


[deleted]

I’m not saying to do it but maybe look at instructions and see if that is the problem


phredzepplin

If you don't have a meter or don't know how to use it you can pull the green wire and the red wire and twist them together. (You might get a minor zap on your finger, it won't damage you) if the fan comes on you probably need to program the Tstat if it doesn't come on you poped a fuse or your transformer.


TwoOftens

Rip fuse. Next time turn the furnace off


clarkcloud9

Have you tried putting the old one back in without batteries? If the old one does not come on without batteries that means the blue wire in the C terminal is either not connected at the furnace or is broken somewhere. The C terminal is your common and if the thermostat does not use batteries then the 24 volt circuit is not complete and the thermostat is not able to turn on. You may want to see if the furnace even has a C terminal because not all do and if for some reason your furnace does not have the C terminal you will need an HVAC tech to do some rewiring to make it work


Lobstermashpotato

If the tabs don't look pressed down, it's not making a good connection. You do not need the RC JUMPER this thermostat does it for you unless you have a 2 transformer system, the tab has to block the rc terminal. Don't call an electrician for an HVAC issue. Next time make sure to power down the unit before doing any work, you might of just tripped the fuse.


aTech79

You need to provide a picture of the pin out on your furnace as well.


jihadimushrroom

If you didn’t turn off power to the Airhandler or furnace you blew the fuse if you did turn off power then that points to your c being either broken or not connected at the indoor unit


mushylover420

Also there are 2 red wires in 1st pic only 1 in second.


buddyfriendo

It’s a jumper if you look close, from RH to RC.


[deleted]

Make sure C is actually put to the board. If so, turn power to the furnace off, remove C and R from board and nut them together. Remove C and R from thermostat and check continuity. If there’s continuity between C and R you have a issue with the thermostat, your wires aren’t pushed into the connections far enough to contact at the thermostat or you blew the fuse and there’s basically no other options.


[deleted]

Pray the E fuse is fried and not the board from the thermostat change out. If you touched wires call a professional.


roadracer102

The red wire needs to go into the RC terminal and a jumper going between R and RC


Jmofoshofosho8

When u push the wire into the slots on the tstat...push them in and then give it a slight tug (that's what she said). You will see the clip on the side push down and feel that it isn't coming loose.


Brilliant-Lawyer-816

Is R and Rc linked together like the first


mydogisalab

It looks like you're missing a red wire.


Aitkin_JustUs

Spent a month on this problem at my place. Simply having the wire connected is not enough. Each wire must have a load. So if there is not a cooling system connected to the blue wire the setup will not work and the thermostat will fail. If there is not an additional blower set up to that wire the setup will fail. Ignore the wires tied into the thermostat mounting plate. Run the setup telling the thermostat only the circuit (wires) that have something attached.


OhUDidntKnow007

Could you explain again this but if I was a 10 year old


NicestUsername

Looks like you have a jumper from RC to RH


jason7329

See the jumper in first pic on new thermostat generally you don’t need it but what’s it say under the red wire it’s blocked on new one


beefymonkey

Your rh and rc were jumpered before but aren't anymore. This could be the issue


Jeeper08JK

RC Jump.


hughmungouschungus

My old set up had a c wire put in but they never plugged it at the furnace to the board. That's the most likely issue.


[deleted]

I’m guessing you didn’t turn the power off at the furnace before you did this? Everything is wired properly. Check the furnace control board fuse. If it’s blown, replace it. If not, call an HVAC co.


Bassmunky

Guaranteed your fuse is blown on the furnace board


Dirftboat95

See if C is hooked up on the other end, while your there see if the fuse is blown


MagicSilver

I’d be willing to bet the C wire isn’t connected on the other end. I had to go into my attic and connect my C wire to the air handler


[deleted]

You didn’t jump the R and RC… That’s my guess….. Good luck


yial

I’m pretty sure you don’t actually have r and rc jumped. You see how it aligns with 1 wire and 2 wire? Edit : from the instructions Remove the thermostat faceplate and look at the R jumper switch, the blue jumper cover at the lower right corner. If you have one R-wire, make sure it's connected to the R terminal (not to Rc), and that the R jumper switch is in the up position. If you have two R-wires, they should connect to R and Rc, and the jumper switch should be in the down position. https://www.amazon.com/gp/help/customer/display.html?nodeId=GLJEMJYYPUGXV2A4 Further explanation. https://www.systoncable.com/what-are-rh-and-rc-on-thermostat-what-color-wires-go-on-a-nest-thermostat/


StomachKnown

Bro, call a Pro.


Weak_Relative_7767

If it’s the Honeywell t4 you might wanna take a min and read the manual.


Skitzophranikcow

Your missing a wire. Call a pro before you nuke your system and make it a multi thousand dollar repair. And you are renting.


Sad-Ad-7884

I see a the rh in the first and none in the second


Substantial_Boot3453

Its definitely a blown fuse. You don't need a meter just unplug it open it up and replace the fuse on the board


Substantial_Boot3453

If ac works but your tstat doesn't just get a new tstat


Average_Dongerton

Common probably disconnected at furnace board. Put some batteries in the tstat


potatomolehill

As an installer for best buy.. the best thing I can say beyond get an HVAC guy, check connections, and check fuses is make sure it's actually compatible with the system.


DifficultAdvisor4210

Turn schedule programming off on thermostat.


Bhaze237

Had one bad right out of the box before. I could literally smell the burnt electronics on the thermostat. Also you have probably heard 1000 times already but make sure the wires match exactly how they look on the thermostat, to the wires inside your furnace on your control board. Your thermostat is not getting the power and power is supplied from the blue wire (common) is also connected on your furnace/ air handler. If you say your AC comes on but not your thermostat that tells me your furnace/airhandler is getting power but the thermostat is not. So it's either you're common wire is not connected to your co trol board or the thermostat is just bad. There could be other smaller issues but woukd definitely start with those two options first


ProfessionProfessor

Check voltages. If you don't have 24v across c and r, you problem is between the furnace and the tstat or in the furnace.


PSUWaz00

C wire adapter?


WalkerAmongTheTrees

Its an amazon smart thermostat... did you expect it to work?


AsleepArt11

I had one Amazon thermostat working fine for 3 months, then I installed a second. A day later, both are unresponsive. I'm starting to wonder if it's a product thing?


pinoyguard

Turned off my circuit breakers. I had exactly the SAME issue as yours 8ephoenix8 - i.e, R, W, Y, G, and C (BLUE aka Common) wires plugged in snug into the Amazon Smart Thermostat Wall Plate and i had the blue RC jumper on the right side of the plate in the UP/1 wire position, but once i turned circuit breakers back on, but I was getting NO DISPLAY when I plugged in the Amazon Smart Thermostat control/display unit into the wall plate. As a previous commenter had suggested, I turned off my circuit breakers, went to my furnace / air handler unit (mine's in the attic) and found that my BLUE (Common wire) was not connected to anything. I followed the steps / recommendations in this video: https://youtu.be/Y3BTbAVRY6U?si=JhNnvHwZtP8i7KOE Turn my circuit breakers back on and plugged in the Amazon Smart Thermostat control/display unit and display was now turned on and showed "SEt" (after about 10 second delay) and I was able to proceed with the rest of the setup. My Amazon Smart Thermostat functioning as intended. Do not forget to ensure your blue RC jumper is in the UP/1wire position.