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Nest thermostat with e294 error, R wire not detected

BruceB
Community Member

I installed a Nest thermostat and it gives error e294, need R wire. However, the R wire IS connected. As per troubleshooting instructions I have uninstalled the device from my Google Home app and reset the thermostat to factory settings three times, and it still gives the error. I have also removed and reconnected the R wire from the Nest base plate two times. It still gives the same error. The furnace worked fine with the old Honeywell thermostat, and still does when I reconnected it again. The furnace has a White-Rogers 50A55-843 fan control board. What do I have to do to get the Nest thermostat to work?

1 Recommended Answer

BruceB
Community Member

For what its worth to everyone else, I spent 45 minutes on the phone to Google Next support, and 95%  of what the Customer Service Rep (CSR) said was the same as the online instructions for troubleshooting an e294 error. Basically, remove the device from the app, then do a factory reset on the thermostat, then try again.  I asked if I needed the C wire.  He could only say, "you MAY" need to add a C wire, or add one of their power adapters, or call a PRO to install it. However, one thing the CSR said as he was half reading out loud from some resource, was that the basic NEST thermostat -- not the learning one -- needed more power than the learning NEST thermostat device. 

I also read somewhere online that the C wire is a common wire which offers a "return" path for the electricity which goes from the transformer to the thermostat through the R wire.  So I installed a C wire from my furnace to my thermostat. But it STILL didn't work when I tried to fire it up through the Home app on my phone.  It gave the same e294 error.  When I had added the thermostat to the app, I had indicated that there now was a "C" wire, in addition to the R, W, Y, and G wires. 

At that point I was ready to send the unit back as defective, but I tried one more time.  This last time when I tried again I did NOT tell the app that there was a C wire.  I just listed the R, W, Y and G wires, and pretended there was no C wire -- even though there was now -- AND THE NEST THERMOSTAT BEGAN TO WORK! And it has continued to work for the last three days.

SOLUTION: So basically, I had to add a C wire (even though no where did anything say for sure that that was what was needed), and then NOT TELL the Home SET-UP app that the C wire was there.  So I hope this helps someone else, and saves that person many frustrating hours!

And if Google Nest engineering reviews this post, I think they need to add better troubleshooting instructions for all of us consumers.  Since they know the exact model numbers of our Nest devices from the QR code which we scan with our phone-cameras, and they know what wires we have from the set-up app, I would think they should be able to add a routine in the set-up instructions for those of us who have basic Nest thermostats and who only have R, but not C wires, telling us how to set-up our devices like I had to discover after many hours of trial and error.

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91 REPLIES 91

Thanks Bruce. Followed your information and also worked for me. I wouldn't have figured that out for hours, or maybe never. Thanks again. 

RDB2
Community Member

Thanks BruceB. Just replaced my LUX WIFI thermostat with the Nest. My Goodman heating & ac unit had only 5 wires Y, W, G, R & "C" wires.  Start up, of the NEST thermostat was with e294 error. If I hadn't found your "reset nest thermostat, remove from "home app"  When I reconfigured the Y, W, G & R wires only in home app and omitted the C wire in home app but still connected C in the Nest thermostat. BAM, working great. 

Atul1
Community Member

My nest is working with this workaround.  But, I have 2 questions in this regard:

1. Currently I am using 2 AAA batteries which keep generating diff errors which I keep ignoring but the batteries keep draining power and when they run out, you cannot connect to Wi-Fi and that can be a problem when I am away and want to turn heat on. Other than using rechargeable batteries, how do you work around this issue?

2. Nest sent me a free power connector but looking at the installation instructions, it is not very simple to install. Has anyone used it and are there any easier ways to use it?

 

Steveintx
Community Member

Bruce.  Thanks for going through all of that pain and suffering. This gif worried beautifully for me. I had the same issue. Connected red, green, and yellow to my a c., And found a live 24 volt wire to connect to C. It should have worked, but only your solution got rid of the dreaded error message. Genius!

ghill217
Community Member

This worked for me as well, Initially tried setting up with R,W, and C. Reset, didn't program the c in, although it was wired, an voila! We're back in business.

Big thanks, Bruce, cheers.

This is the way. Thanks brother.

pk64
Community Member

What if you don't have a common wire. Bruce can you please take a picture of the  C connection and share  . I'm having that same problem

hellquco
Community Member

Your solution fixed my exact problem, thank you!

SOLUTION: So basically, I had to add a C wire (even though no where did anything say for sure that that was what was needed), and then NOT TELL the Home SET-UP app that the C wire was there.  So I hope this helps someone else, and saves that person many frustrating hours!

KevC
Community Member

This fixed my exact same problem. I'm glad I found this post quickly and didn't spin my wheels for hours. Many thanks for the solution!

Bbolder
Community Member

Awesome Bruce. Worked like a charm. By the way I'm BruceB as well. Appreciate it. 

JayGu
Community Member

Thanks Bruce! Solved for my initial install e297 error by telling the system there was no c wire even though a c wire is physically installed.  Here is what I did in addition: after the install and everything seemed to be working, I went into the app and updated the wiring.  I simply added the c wire to the app, and everything continued to run properly. I do not know if this will make a difference with keeping the batteries charged, but at least the software accepts its presence.

Rgl
Community Member

That's the trick. Attach C wire, but do not check it on app. Thanks.

zack4257
Community Member

Thanks Bruce, it worked for me too.

One thing though, I also had to choose RC and not R to fool it into to working.

Jhonleanmel
Community Specialist
Community Specialist

Hi zack4257,

 

That is great! It looks like we can consider this one complete, so I will lock the thread shortly unless I can help out with anything else.

 

Regards, 
Mel

Rgrele
Community Member

I tried not reporting the "C" wire during setup (although it IS connected). Still getting the same error. Google Nest:  "E294: R wire is required".  

Tried 4 times. Did complete resets. Double checked all connections.

Re-installed the old reliable Honeywell using the SAME 4 wires and that one works fine.

Disgusted!

Rgrele
Community Member

UPDATE: Upon further investigation, I ordered a 24V AC adapter from Amazon thinking that my wiring wasn't getting the correct voltage. Before I installed it into the system, I decided to try to hook up the Nest thermostat one more time. When I inserted the red wire into the hole, the tip of the wire broke off (perhaps it was defective?). So I stripped off some insulation and reinserted the red wire and performed the setup one last time. This time NO E294 error! And everything worked. 

I'm assuming that there must have been something wrong with the red wire not making a good enough contact when inserted the previous times. 

Now that it's working, I won't need the 24V AC adapter. My 10 year old Trane furnace evidently has enough power to make the Nest happy.

JimR
Community Member

I was getting the same repeated error telling me the red wire was needed even though it was fully connected. Reset and retried a few times. Then by chance I decided to designate the Rc terminal instead of the R terminal for the red wire in the home app. Started working immediately.

Edsmith29
Community Member

I had the exact same problem. Deleting the device from google home, reinstalling it and changing to Rc designation for the red wire worked. Thanks so much!

I will be trying this.  Just want to make sure the system is still working as needed.

jeffp0103
Community Member

Jim

Thanks for the tip. I moved the R to Rc, factory reset and am not working fine. i was happy this worked since I'm in an older home and running an additional wire would have been no easy task. 😀

Pinemartin
Community Member

I had the problem, and was able to fix it by doing a factory reset.  I just went through the same setup questions again while the unit was plugged in and the furnace powered.   This time the setup worked perfectly with no errors.   Seems weird but definitely worth trying!

knowmoore
Community Member

We had the exact same issue, and BruceB's solution works perfectly. Google would save a lot of money and time by simply updating the instructions. Don't check the "c" wire when it asks which wires are present!

Bercpa2
Community Member

I tried all of the above fixes and several factory resets with no luck.  I'll give them on their support was good today.  Finally I factory reset again and there's a point where you can tell it that it's already installed.  It asked me questions it hadn't asked before then FINALLY showed me a display showing which wire it did not find.  It was the white one.  It had never shown me that screen before.  Hopefully it will help someone else!

pengee
Community Member

I had this same issue. What I noticed was that in the app you could see the wiring configuration and it had all the wires I had selected during setup, but they all said something next to them, I can't remember what, but it indicated they were missing or not connected. From this screen you could re-add wires and it worked for all of them, after which they showed their correct state, except for the R wire. You could not remove the R wire but it showed the option.

For the factory reset, I powered the furnace on and with the app, selected the alternate setup option where everything had been installed, rather than walking through the steps. This asked a somewhat different set of questions than the other setup path and at the end everything was working, no errors.

calsabey
Community Member

Followed what you did here and it worked for me...at least I think. Thank you!

bsmaven
Community Member

Same messages showed no wires connected except my power connector. Tried removing red and white and my red copper broke off and is stuck in connector and can't get it out. Are these connectors bad? No thermostat should be this much trouble.

bsmaven
Community Member

Anyone know how to remove a broken piece of copper wire from the base plate connector? I try pulling up the tab and grabbing it with the tip of needle nose pliers, won't budge which is why it originally broke in first place. Any ideas are welcome.

DaveRak
Community Member

Spent hours trying to figure out the same error.   Im returning it.   Can only imagine the frustration 5 yrs down the road of future app updates or the scroll bar not working.   Too complicated for a Thermostat.

mramnauth
Community Member

Thanks Bruce. Worked for me also. Totally agree that this is far too complicated. If this causes issues to the device, that is a terrible design. Google please take these constructive critiques to design a better experience. This has been, by far, the worse google experience- not up to par with the ease of the rest of devices, phones, software that I've used. 

Now that it is working, it is great. 

 

Clemu93
Community Member

Came here to find ideas on a possible fix, just figured this would also help. Constant Error with the Red, looked at my old thermostat and noticed a jumper from R to Rc, reset everything again for the 5th time, this time in the settings i did not select the R and instead the Rc. Took me to a completely different screen asking me for fuel type and induction type, entered in the info and it fired right up! No c wire needed, although mine was present in the wall the old thermostat didnt use it, and if need be i just need to hook it up to the board and to the nest as its already there. 

Lylej66
Community Member

I have a 4 wire system (no C wire) and I got error E294 even though my red wire was connected to the R terminal. My original Honeywell thermostat had a jumper between the R and RC terminals. I deleted the device from the app and did a Factory Reset on the thermostat and ran the Setup routine again. This time I told the app my wires were connected to the W, G, Y and RC (instead of R). NOW IT WORKS! No errors.

dflkgj340598
Community Member

Like Lylej66 I got the same error. I tried the ones above and it did't work.

My current setup:

- Wire on RH and Jumpers on RH and RC

- Wire on Y1

- Wire on G

- Wire on O

- Wire on C

With no jumper for RH/RC, only had wire to enter into R on Nest board.

In the Home set up, I selected RH. Error always came up. Reset a few times, checked wires, tried without C in Home app... still got the error. I then tried setting RC and not RH. Error went away, but it asked what I wanted to use, only heat or cold after selecting heat delivery forced air. Well that sucks I thought.... but better way to monitor and I could do alerts for when house got too hot or cold. My current thermostat I had to switch one at a time, but it was not smart. After it was done, from the main screen showing heat/cool temps I selected "select mode" icon, (on the far left), then selected heat*cool option.  Then lowered and tested the sliders above and below the preset amounts..... It did turn on the heat and cool when it should.  Hope this helps someone else.

smk402
Community Member

Thank you for this!! My system already had a C wire, but this solution of resetting the thermostat and ignoring that wire worked perfectly!! Google support should pay you for helping so many people with this same issue!

SVTRocket
Community Member

I received the same E294 code, no R wire detected. Before trying the above troubleshooting,  I re-checked the red wire labeling on my Honeywell programmable thermostat.  It was labeled RC on the wire, so I did a Nest Thermostat factory reset (thank you YouTube).  During the 2nd attempt at Home set-up prompts, I selected RC as Honeywell common wire (which is relabeled R with the Nest stickers). This then gave me the additional  prompts, (type of heat gas, electric,.etc.)which I didn't get initially and was finally able to finish set up with no errors. To summarized,  be sure to check the labeling of the red wire in your old thermostat and enter it correctly in the Nest set up.

TE1
Community Member

Same issue... Tried a number of things of which nothing worked. My fix was doing a factory reset on the unit itself. (Trying to delete my home and adding it back did not work because it kept saying there was an error connecting to Bluetooth.) Deleting my home on the app one more time. Added my home in the app and went thru the entire install again. When it asked for which wires I had, I put everything I have in except for the C (thank you to the others here who confirmed that worked). I have the C but did not check it as one that I had. It was at this point the first time when I installed it that it came up with error 295 R wire. This time, no error at this point just smooth sailing through the rest of the set up and now everything is working fine!

ReadyAllRow
Community Member

I ran through this with no success, then used hint from Bercpa2:  factory reset and there's a point where you can tell it that it's already installed.  I put in W, Y, G, R & C and this time it reported it did not find Yellow and Green!  I re-inserted them and Voila it works.  Suggest that you pull all wires and reinsert firmly - pay no attention to the claim it is the Red wire that is the problem.

Hi Guys,
 
I think I understand the steps, but it is still not working for me.
 
I did a factory reset, added thermostat, specified the 3 wires I have (Red, Green and White) and also specified that I have C and it is still not able to detect G and C.
 
Any ideas?
 
I am willing to talk to someone on phone to get this.
 
Thanks
Atul

UFGators
Community Member

Hi Atul,

  The only thing I can tell you is that there are 2 or three different methods in this thread.  I tried all three (probably twice) and finally it worked.  Keep trying and you will get it eventually. 

CestMoiLinh
Community Member

Ensure wires are newly stripped/snipped and inserted to fully depress clips. Noticed that my R wire was only partially depressed though I had jammed it in, albeit crookedly. Also noted that white wire was marked as W1/O/B which gave me option on setting up the furnace, whereas before I didn't have that option. 

Fhinton58
Community Member

I had the same exact issue. I will not write a long review from my phone but I read several fixes suggested in the reply section of this comment which were all great and worked for each individual. I was going to do the trick the system hack by installing a c wire without telling the system it was there but then I quickly lost confidence in this fix as several posted comments mentioned that this could have advertised effects on the HVAC system. I instead ended up doing several factory resets and on the last one I told the instalation guide that I had a common wire when I did not. The guide then informed me that it detected W,R,G and Y but not C. I found this perplexing as R had been the undetected wire the entire time before. The instalation would not allow  me to complete it without the mentioned but undetected C wire. At this point I returned to the beginning set up once more and completed the wiring with R,G,Y, and W wiring terminals. The system sensed it, allowed me to continue the setup and it has been working now for 3 hours. I will run a 5 wire HVAC wire to bring the system a C wire. But for now, this is what I did to fix the error mentioned by BruceB.