Returning the Nest thermostat

[jupiter8boy]

I'm trying for 5 days to get the thermostat to display the correct ambient temperature and I gave up.
I tried anything what one can read on the internet but nothing helped. (tbh there's some real nonsense online about this subject!). This must also be the only thermostat that cannot be calibrated as well (NO IT CANNOT, despite what you may read on the net). The displayed ambient temperature is off by +0.8 °C up to +1.4 °C constantly. Compared to other thermostats I have it easily warms up and cools down way too slow.
Humidity is off by at least +20% as well! 
I always wanted a Nest thermostat but needless to say I'm very disappointed, certainly since the Nest goes around as a high-end item!
I wish I've read those many comments before about people complaining ! No wonder the second hand stores are full with those... 
Unless someone comes up with a real hack to get this thing to work properly, this thing goes back to the stores in exchange for a Honewell Lyra!

[CoolingWizard]

How are you specifically measuring the ambient temperature and humidity at the same location as your Nest thermostat? The Nest uses 10 thermistors to calculate the ambient temperature and moisture.  At your home, Is the hole behind the thermostat sealed?  Is the thermostat located 5’ above the floor and not exposed to direct sunlight? 

I am just curious as to how you performed the science behind your claim.

The AC Cooling Wizard

[jupiter8boy]

Thanks for your reply.
To your questions:
How are you specifically measuring the ambient temperature at the same location your Nest thermostat?  Yes. I only have the Nest thermostat unit, no additional/external sensors. It's in a draughty free location on the wall, no direct sunlight. Not close to radiators or so. (same location as my previous 2 thermostats)
Is the hole behind the thermostat sealed?  Yes.
Is the thermostat located 5’ above the floor: Yes. 

and not I direct sunlight? Yes.

[CoolingWizard]

You say the Nest is not accurately assessing the correct ambient temperature. I am confused now. How is it you feel the correct temperature is not being displayed?  I thought you meant that the nest was saying it was 75°. and your other device was saying it was 72°. Or something like that. 

AC Cooling Wizard

[jupiter8boy]

When I compare the displayed ambient temperature to my previous Siemens or spirit temperature meters the Nest is allways off by at least +1.5°C. To do the comparison I have placed the other meters on the cupboard or hung them on the wall - allways closeby each other.
I'm surprised that there is no built-in calibration or compensation feature like eg other brands btw.

[CoolingWizard · Accepted solution]

Personally, I trust the nest thermostat because its design uses no less than 10 thermistors to accurately average the temperature. Most devices use one or two thermistors to average. There is enough variance in the thermistor to allow for a variance in temperature of a degree or two that’s why I fully trust the nest because again, it uses 10 thermistors an average is the weight of the values to get the temperature of the ambient air around the thermostat.

AC Cooling Wizard

[Jenelyn_O]

Hi there,

Thanks for reaching out. I hope you get the answer you're looking for. If you still have questions or concerns, please let us know. 

I appreciate your help, @CoolingWizard.

Best,
Jenelyn

[Jake]

Hey jupiter8boy,

I wanted to check in 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.

Best regards,
Jake

[jupiter8boy]

Hi Jake, thanks for reaching out but unfortunately no. It seems that this is a built-in feature 😉 
I just did one last test: completely resetting the Nest (again) in a completely other location where there is zero possible interference. The same result is the same as before: the ambient temperature is always too high. It is really mind boggling it is not possible at all to manually calibrate the Nest. My wife and I are very upset about this: a high-end apparatus with really rave reviews. How is it even possible that it cannot even display a correct room temperature? I mean, that's the baseline to start with!
Anyway, we have decided to get rid of it and possibly go for the Honewell Lyric (which btw has a manually calibration feature - like all other thermostats on the market)...

[jupiter8boy]

One more thing: I've noticed that when you reset the Nest, it shows the correct room temperature but after 10 minutes or so, it's too high again; Now, if at some point there was a setting or so just to say to the Nest that this it the correct temperature and use that as baseline.... 

[CoolingWizard]

@jupiter8boy , the Nest thermostat has 10 separate sensors working to together to calculate a far more accurate temperature than your typical store bought digital thermometer which have one or perhaps two thermistors sensors.  What can affect the thermistor? Well in the case of the Nest Thermostat, drafts from the hole in the wall the wires come though, sunlight hitting the wall the nest is attached to.  Nest being located in drafty areas.  Ideally the thermostat should be located about 5’ above the floor near the HVAC air return.

AC Cooling Wizard

[Jenelyn_O]

Hi there,

@CoolingWizard and Jake, thanks for your help. 

@jupiter8boy, you can visit this support article for additional or complete information about the situation you experienced in your Nest Thermostat. I hope that helps. 

Best,

Jenelyn

[Dan_A]

Hey there jupiter8boy,

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

Thanks,

Dan

[Dan_A]

Hey there,

We haven't heard from you in a while so we'll be locking this thread if there is no update within 24 hours. If you need assistance or want to discuss topics, feel free to start a new thread.
 

Cheers,

Dan