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Nest Thermostat not turning a/c unit on

zukabaker
Community Member

Hello All 

 

So recently we had a nest thermostat installed in our bakery by our HVAC team and it was all working fine.

The building we are in has a shared sprinkler/fire system that was set off the other day and since then our nest does not turn on the a/c unit. the HVAC guy says that the alarm is causing the voltage to drop at the connection and that is the reason why it has been dropping out. So we bypassed that and the nest still will not work but the old thermostat does.  I am sure that I am not explaining this the right way but basically the nest thermostat does not seem to be connecting and I am curious of any steps to take or try before asking for a new one (less than a year old)

Do I have a defective nest thermostat?  I really love it because I could program from my phone.

15 REPLIES 15

Patrick_Caezza
Platinum Product Expert
Platinum Product Expert

Has the alarm condition been fixed and the alarm reset?

Commercial HVAC systems are tied into the Fire Alarm so that it gets shut down during an alarm. 

Post a picture of the old thermostat's wiring and one of how you have the Nest wired.


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Patrick
It was working perfectly before we had the issue and yes the alarm company claims that the alarm has been reset.  HVAC says that there is a drop in voltage at the unit that is causing the the a/c to not turn on. We replaced the NEST with the old thermostat and it works perfectly so HVAC says that the NEST is not working correctly.  Seems weird to me that the old thermostat works but as soon as we put the NEST back on it odes not.

 

Patrick_Caezza
Platinum Product Expert
Platinum Product Expert

What's the make and model number of the old thermostat?

The Nest thermostat is basically a small computer and without the correct voltage (24VAC) being supplied it won't work correctly. The old thermostat could be of many different types and most use replaceable batteries to power themselves or they just don't need power.


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Paul

 

Why would the NEST just stop working when it was working just fine for almost 2 months and did not have any issues until this most recent alarm cutoff of the a/c unit?

 

There is a common wire supplying power to the nest it just will not power the unit on

My hvac tech says that it is not working an he does not understand why. The old unit uses the exact same wire setup as the NEST.  I really fell as the issue is with the NEST and not my system, yet it is impossible to get a response or a hold of any body to discuss.

Jeff
Community Specialist
Community Specialist

Hi zukabaker,

 

It looks like the conversation dropped off a bit here, so I wanted to check in to see if you were ever able to get this worked out or if you're still looking for some answers. If you're still needing help, please let me know and I would be happy to work with you on this.

 

Thanks,

Jeff

zukabaker
Community Member

Jeff

 

I would like to be able to exchange the unit but Google has made that Impossible and we have added a different learning thermostat and that works fine when we connect the Nest nothing happens and the unit does not turn on.

I tried contacting Nest about a warranty exchange and that is lesson in absolute frustration dealing with them in anyway.

aatienza
Community Specialist
Community Specialist

Hey zukabaker,

 

Oh no! I'm sorry to hear that. Do you have the case ID from your interaction with our support team so I can take a closer look?

 

I appreciate the help, Jeff.

 

Thanks,

Archie

aatienza
Community Specialist
Community Specialist

Hey zukabaker,

 

I just wanted to follow up to see if you still need our help. Please let us know as we would be happy to answer any questions you may have. 
 

Thanks,

Archie

aatienza
Community Specialist
Community Specialist

Hey zukabaker,

 

Just checking in to make sure that you've seen our responses. Please let me know if you have other questions or concerns as I will be locking this in 24 hours if I won't hear back from you again. Feel free to start a new thread and we'll be happy to help.
 

Thanks,

Archie

truthfully the service I was offered was terrible.

I have a defective thermostat and Nest refuses to do anything about it.

Actually never got that far when i explained that the tech replaced the nest and all worked well I was told that they needed the invoice from the tech when I explained that he did not charge me to swap them out the insisted that there was nothing that they could do.

 

MelbaDT
Community Specialist
Community Specialist

Hey there, 

 

We're sorry to hear about your experience. If you could provide the case id of your interaction, we'd appreciate it — we'd like to investigate it further. 

 

Best, 

Melba

Never got that far read my previous post.
The tech refused to do anything stating that I needed to provide the invoice from the service call. When I told them that I did not have an invoice as I was not charged to do the changes or swap out the unit they said well sorry nothing we can do about the issue and would not listen to anything that I had to say and just kept[yt repeating about needing to see the tech(hvac) invoice.

I swapped my old thermostat back on and the a/c works fine but when I tried to swap the next back on it will not turn on the unit.

MelbaDT
Community Specialist
Community Specialist

Hey there, 

 

Sorry for the overdue response —I overlooked this. 

 

I've found the case id of your interaction with our support team by running the email address associated with your Community profile on our system.

 

Upon further review, we really need a documentation from the HVAC team who checked your system. Without it, we really can't proceed with the replacement of your device. I understand this is not an ideal answer you're hoping for but we hope you understand. If you can't provide the receipt showing the tech's recommendations, we'll be glad to try some troubleshooting steps with you. 

 

Best, 

Melba

Thus is far from an ideal response. It has been over a month since the last reply and yet this seems to be the way that Nest works.  I have a service contract and when the thermostat was not working I called him and he can and looked at it and said there is an issue with the thermostat and swapped out the  Nest for the old one and it worked fine. He went to the roof and checked the unit and saw nothing wrong tried the nest again and it did not work so we went back to the original thermostat and lo and behold it works so it has to be there is an issue with the Nest but as a company you expect me to jump thru hoops to get a replacement and truthfully if the delay in your response is any indication of how the company works it really is just a game of wear down the customer till the give up.  What would the tech say any different than what I am telling you? I am saying what he told me. 

Elias-MTL
Community Member

how to check if nest wires receive the correct voltages and what are these voltages. The heat pump cooling was perfectly operating last year, but is not working this year for AC