Nest thermostat not cooling to set temperature

[KellyT]

 

Hi Everyone,

We lost power a while back at the beginning of July and ever since out ac will not cool to the set temperature. We have had our unit inspected twice and told it is running fine. You can no longer feel the cold air blow through the vents like before, we have reset our thermostats and the house still doesn’t not cool, for example it is 71 outside so we set the air to 65 to see if the house will cool down since the technician said it was because the excessive heat it our inside temp is 69 and the thermostat says 2+ hours to cool down do set temperature of 65 we set this temp last night before we went to bed and it is still sitting at 69. My thing is that if its 71 outside there is no reason a “working “ unit should not be able to reach 65. Has anyone had this issue and what was the solution. Trouble shooting has not seemed to work. 

 

[zoeuvre]

Hi KellyT, 

Thanks for bringing this to our attention, and I'm sorry to hear about the situation. A few questions: 

1. Is this newly installed?
2. When did cooling last work?
3. What type of system do you have? (Heat Pump or conventional type)
4. Do you see any message or code on your thermostat?
5. Have you set up a temperature schedule for your thermostat?

Also, please help us with a photo of how the thermostat wires are connected to your Nest Thermostat E's base, including its complete power readings of Battery, VOC, VIN, and lIN on its Settings > Technical Info > Power.

I'll look forward to your response. 

Best,

Zoe

[zoeuvre]

Hi there, 

I want to check and see if you are still in need of any help. Please let me know, as I would be happy to assist and answer any questions you may have.
 

Thanks,

Zoe

[KellyT]

 

 

 

 

Hi thank you for reaching back out to me, this is not a newly installed thermostat it has been installed for a little over a year now, the last time it worked was July 4th. 

[zoeuvre]

Hello KellyT, 

Thanks for the information. The power readings we need to check are the ones that you have on your actual Nest Thermostat E. Just go to its Settings > Technical Info > Power and list down its Battery, VOC, VIN, and lIN.

I'll look forward to hearing from you again. 

Regards,

Zoe

[KellyT]

 

 here they are top one is upstairs thermostat second one is downstairs thermostat.

[Jenelyn_O]

Hey KellyT,

Thanks for sending us the photos. Your Nest Thermostat E has actually fine power readings. Are both of your thermostats connected to the same HVAC system? Please try to swap your thermostat display to isolate it further. Monitor if it will make any changes. 

I appreciate the help, Zoe.

Best regards,

Jenelyn

[KellyT]

Yes they are both connected to the same HVAC system. 

[Jenelyn_O]

Hi there,

Thanks for letting me know. Were you able to try swapping your Nest Thermostat display? Please let me know how it goes.

Regards,

Jenelyn

[KellyT]

We swapped them and nothing has changed so we swapped them back 

[jstecken82]

This has happened to my thermostat as well

[KellyT]

Did you ever get it resolved?

[Zealotline]

It's been happening to mine too for at least a month or two. I swear all of my Google smart home devices (like my Home Minis) have been malfunctioning during that time!

[lmrkc]

We experienced a power outage very briefly Sunday and it’s been the exact same for us.
We are having the same issue and it’s not our unit it was checked and passed without issue. Stuck at 69

[KellyT]

I have had my HVAC checked out twice and my HVAC is fine as well, I reset the thermostats and still having the issue 

[lmrkc]

We put in a C Wire - charged the device - added a new one just in case (that works great) so it’s the this one. It all started after the surge!  We replaced our add on delay on our unit thinking it was that also. 

Someone randomly posted to change the room the device is in so upstairs is now hallway and it hasn’t cycled off yet but is still stuck on 69. The thermostat can easily get to 65 any other time but after the surge the fan doesn’t come on as quickly when asked to and the temp doesn’t drop. I’m not sure what we can troubleshoot that we haven’t at this point. 

[Lokid]

This happened to me yesterday.

Did  you find a fix?

[KellyT]

We are still having the issue as well. I have had three different companies come out and say my hvac is fine. The only thing I can think of is the thermostats. I have checked my app and it shows my thermostat has shut off from auto schedule when there is no schedules set up on either of them. 

[Zealotline]

I'm convinced it's a software problem with multiple Google devices. The issues I've had with my Google Home Minis started around the same time that I noticed my thermostat acting up. I've been on a schedule I created for all the years I've had the thermostat, so that hasn't changed. I didn't set up the common wire this summer (my furnace doesn't work with the common wire installed, so I have to remove it when the furnace needs to be used), but I can see on the app when that's the issue...it will say how many minutes until it reaches that temp. But the issue that's been going on for the last few months will be that I pull up the app after I start noticing my bedroom (where my additional sensor is located) is getting too hot. I see the thermostat temp is set at 75 degrees, it shows the room is 77 degrees, but the AC is not even trying to run until I manually bump the set temp down a few degrees. This happens also when I have the temp controls set up to read the main thermostat in my living room, so I know it's not just an issue with the sensor. Other people's screen shots on this thread match exactly what I've been seeing.

Now that I think of it though, for a month or two before this started happening, I several times got a notice on my app that the sensor's battery might be low. I knew it wasn't, but I replaced it anyway and still got the message. But I haven't seen that message since this other issue has started.

[lmrkc]

Looks familiar 🙂

 

[lmrkc]

So we may have found a work around not sure but it’s working….

1.) We changed the room location of the device in the app - why it matters? I don’t know but I read it online and did it.

2.) We added an Cwire because our unit is 12 years old I think and the battery after charged through the port only survived a few hours l so feels like it may have been on its way out.

3.) We went in and added a new schedule on the app. We didn’t have auto schedule on and we didn’t set a schedule but we thought maybe it would override whatever the app was trying to do. It’s responding the way we know it to now after this.

I think it’s working! It may not solve everyone’s problem but I think for us it may be the solution.

Also if you’re setting and resetting your device or even after the surge it may have reset back to default on your schedule so ignore the auto schedule toggle and double check it didn’t set a schedule for you in schedule at the bottom  of the app.

[JohnstonHome]

I wish I could get my ac to cool to 72 or 69,  we had a power outage last Friday since then i can’t get my temp below 80 normally 86-82 in my home. I have reset the base to factory, i set a schedule on the base for everyday to 71, i did the test and it’s says testing cooling ac should be on, check the vents the air might take a couple of min to cool down, done, troubleshoot. If i select troubleshoot it’s says nest.com/t02 but can’t find anything online for this code except a generic cooling answer, i deleted the app and reinstalled and had the issue where the screen freeze on iPhones on location screen so i used my sons android and set back up the app, i can feel cool air blowing slightly out of most vents, but during the day it’s 86 in my home. I checked for a box from ac company but did not see one, my power readings are as follows: battery 3.844V, VOC 36.70V, Vin 7.78 V, Lin 20 mA (a), I don’t have a c wire but my thermostat is approximately 3-4 years old and have never had one. I have checked all wires and made sure they were in all the way and the checked power again which now shows- battery 3.811V, VOC 8.42, Vin 8.42, Kim 20 mA (a), also ran test and again same thing not really an answer if i select trouble shoot gives me same t02 and if I select done it goes back to main screen, i have temp set to 71 and it’s 80 after 3 hours of ac running and has 2+Hr on everyday all day long since the outage. I have made sure that there is no energy saving programs on that would adjust my temp during day and system kicks on and kinda blows cool air but to cool to 80 if I am lucky. Example since I started typing this thread now it 81 in my house. I even tried changing my location from upstairs to hallway like suggested and have read and done everything I have found on nest community with no change. However since there are over 50 comments in the past 2 weeks of other nest thermostat owners having the same issues from all parts of the us in different size homes and from brand new install to 13 year old thermostats I think the common denominator is the nest thermostat causing the same issue. I can not figure out how to upload my photos but either way all other photos uploaded seem to have the same pictures as mine with the same problems. Please help it is hot in texas! 

[Lokid]

Well finally got my answer. This should  help people with the same or similar issues.   

We had our HVAC company come replace so board that controls the fan.

They said most of these issues with the Nest thermostats is when it gets a power surge or outage it somehow fries the board that controls the blower fan so it cools the air but doesn't blow it out orblows slow.

It makes it where the fan blows until it gets the engage AC call.

They said Nest has yet to admit the issue or found out how to stop it before you have to buy a new board. 

[Lokid]

Well finally got my answer. This should help people with the same or similar issues.
We had our HVAC company come replace so board that controls the fan.
They said most of these issues with the Nest thermostats is when it gets a power surge or outage it somehow fries the board that controls the blower fan so it cools the air but doesn't blow it out orblows slow.
It makes it where the fan blows until it gets the engage AC call.

They said Nest has yet to admit the issue or found out how to stop it before you have to buy a new board.