AC running when in heat mode

[Lroe]

Have a gas furnace, separate AC. 
have had a nest for 4 years. 
just this past week the AC has started running when the sunlight hits the nest even though it is only in heat mode. My AC was covered for the winter!!

[CoolingWizard]

What are your safety temperatures set at? Thermostats should not be located at a location that direct sunlight can shine on the thermostat. 

The AC Cooling Wizard

[Lroe]

Low safety 45 and no high safety. 
the wall where the thermostat is mounted gets limited direct sunlight, but usually in the winter due to angle of sun. 

[CoolingWizard]

Like you, I am at a loss to understand why this would happen.  That being said, there has been no changes to the Nest Thermostat system equipment configuration. Ie., not reconfigured to a heat pump system. 

The AC Cooling Wizard

[05soxfan]

I am having a similar issue where starting on Feb 1, the AC compressor kicks on.  I think it ran for an hour when we were not home.  I caught it tonight while home.  It's in heat only mode with 45 low and 95 high safety temps.  It's mid 40's ambient temp in Chicago area.  So weird the AC compressor kicks on.  I turned the compressor breaker to off and set nest thermostat to off.  Just searching for a possible solution to try to help our HVAC tech out.  

[Jenelyn_O]

Hi folks,

Chiming in, thanks @CoolingWizard, for assisting this thread.

Direct sunlight can cause a thermostat’s temperature sensor to heat up, so it may think that the ambient temperature in the room is higher than it actually is. Google Nest thermostats use Sunblock to compensate for direct sunlight and keep your home comfortable.

@Lroe, enabling your thermostat Sunblock feature might help. 

You can try these steps on how to do it:

On the thermostat

1. Press the thermostat's ring to bring up the Quick view menu.
2. Choose Settings
3. Turn the ring and select Nest Sense.
4. Choose Sunblock.
5. Select Yes or No to turn Sunblock on or off.

With the Nest app

1. Select the thermostat on the home screen.
2. Tap Settings
3. Select Nest Sense.
4. Choose Sunblock.
5. Tap the switch to turn Sunblock on or off.

With the Home app

1. Touch and hold your device's tile.
2. Tap Settings
3. Open Temperature Preferences.
4. Scroll to Nest Sense and choose Sunblock.
5. Tap the switch to turn Sunblock on or off.

@05soxfan, you can also try the steps above and let me know if that works. 

Best,

Jenelyn

[Jenelyn_O]

Hi there,

I wanted to follow up and see if you still need help. Please let me know if you're still having any concerns or questions from here, as I would be happy to take a closer look and assist you further.

Best,

Jenelyn

[Jenelyn_O]

Hi there,

I'm just checking in to make sure that you've seen our response. Please let us know if you have any other questions or concerns as I will be locking this thread in 24 hours.

Best,

Jenelyn

[05soxfan]

Hello, my problem is not related to sunlight as the thermostat does not get hit by sunlight at all.  I have hot water heat as well so been relying on that until I can try a thermostat swap.  I have turned furnace off and turned AC breaker off.  Hopefully a tech can help, but I reasonably sure I need a new thermostat.  I will probably try a different brand, or at the least a non learning version.  Thanks again.

[Jenelyn_O]

Hi 05soxfan,

Thanks for letting us know about the issue you encounter — I'm sorry for the trouble this may have caused you. If you're experiencing unexpected mode changes with your Nest Thermostat, it might help to check its Energy History. It shows when the system is activated and why.

You can follow these steps on how to check your Energy History:

1. Open the Nest app and tap your Nest Thermostat icon on the home screen.
2. Tap History
3. Your 10-day summary should appear. Tap on any day to learn more details about your heating system’s energy use.

Best,

Jenelyn

[05soxfan]

Yes I did that.  It showed several days that the AC ran for 45-1 hour exactly. 

[Jenelyn_O]

Hey 05soxfan,

Thanks for the update — some unusual behavior of Nest Thermostat can be caused by the schedule learned by the thermostat automatically. 

Check if your thermostat learns some schedules:

• For Nest Learning Thermostat just open the Quick View menu, then select Schedule. 
• For Nest Thermostat E just go to Settings then look for Schedule.
• For Nest Thermostat 2020
  1. On the home screen, touch and hold your device's tile.
  2. Tap Settings then Schedule.

Keep me posted.

Best,

Jenelyn

[aatienza]

Hey there,

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. 
 

I appreciate the help, Jenelyn.

Thanks,

Archie

[Jhonleanmel]

Hi everyone,

Just one quick final check in here since activity has slowed down. We haven't heard from you in a while so we'll be locking this thread if there is no update after 24 hours. If you have any new questions, updates or just a discussion topic, feel free to start a new thread in the Community.

Thanks,
Mel