Google Nest thermostat false temps

Kooky Kats

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Aug 17, 2002
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Recently, we replaced our boiler with a new one. We had the old one controlled by our Nest thermostat. Now, with the more modern efficient board on new boiler - our Nest is way off in reading temps.

According to some research, the wiring needs to be 3-wire to be accurate. My boiler dude has dragged his *** for 3 months finishing the job and is baffled. The Nest reads 81° when clearly the house is just about 65° and we’re freezing.

Any tech nerds or mechanical folks out there that can lend me some advice? Now that Google bought Nest, customer service is non-existent.

✌🏻
 

AustinTXCat

Hall of Famer
Jan 7, 2003
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When performing basic troubleshooting, initially evaluate change.

Is the thermostat also new or are you still using the old unit? Have you verified if Nest is compatible with your thermostat? Was the previous wiring also 3-wire?
 
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catlanta33

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Aug 27, 2013
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Thought the sensor on the Nest is what's picking up the temp. So it could be mounted in the warmest part of the house and that's why you're getting a higher temp there.

But, I know a guy - @anthonys735
 

anthonys735

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Jan 29, 2004
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I'm not super familiar with the Nest. We use Ecobee, Honeywell, and Carrier mostly. Sounds like a setup issue with the new boiler installed. A boiler swap out is easy, typically takes a day max. Get that fool back out there and tell him to fix it.
 

anthonys735

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Jan 29, 2004
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I don’t have one of these internet connected thermostats but mine reports the temperature where it is located in the house
Unless you have a room specific extended sensor, all of them do that. I would assume it's either effed or they have a calibration feature. I thought Nest had good support so that's disappointing to hear. OP needs to get his lazy contractor back out though, IMO.
 

Kooky Kats

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Aug 17, 2002
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When performing basic troubleshooting, initially evaluate change.

Is the thermostat also new or are you still using the old unit? Have you verified if Nest is compatible with your thermostat? Was the previous wiring also 3-wire?

My painter installed the Nest to our old boiler (2-wire setup) and worked flawlessly for 3 years. The 50 year old boiler gave out in early October.

We had new one installed. Controlling 3 separate zones. All using exact thermostat controllers and same wiring. Took fool, like I said, 3 weeks to complete job so the Nest battery was dead...

Since such time, to get dude back, the Nest crapped the bed and reads too high. When I crank it beyond the 81° reading the baseboards kick on.

I dunno. Reset the Nest to factory settings 3 times. Nothing is making it read the correct ambient temp of my room.

Not sure wiring is the reason.
 

Kooky Kats

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Aug 17, 2002
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Unless you have a room specific extended sensor, all of them do that. I would assume it's either effed or they have a calibration feature. I thought Nest had good support so that's disappointing to hear. OP needs to get his lazy contractor back out though, IMO.
OP is about to eviscerate said contractor for being a piece of ****. home advisor is gonna be raining black on that dude... $5500 for new boiler that can’t be controlled.
 

AustinTXCat

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Jan 7, 2003
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My painter installed the Nest to our old boiler (2-wire setup) and worked flawlessly for 3 years. The 50 year old boiler gave out in early October.

We had new one installed. Controlling 3 separate zones. All using exact thermostat controllers and same wiring. Took fool, like I said, 3 weeks to complete job so the Nest battery was dead...

Since such time, to get dude back, the Nest crapped the bed and reads too high. When I crank it beyond the 81° reading the baseboards kick on.

I dunno. Reset the Nest to factory settings 3 times. Nothing is making it read the correct ambient temp of my room.

Not sure wiring is the reason.
I'm not too familiar with Nest. Having said that, I'd suspect inputs are similar from the Nest unit to the same exact thermostat controllers and wiring.

Questions: Can you replace Nest battery? Will the Nest unit accurately report lower temperatures? If so, then what range?
 

catlanta33

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Nest support is atrocious. Won't even sell their thermostats anymore because the margins are so low and you always have headaches trying to commission them. Has tamper features that render it useless until you get through tech support (can up hours) so you better install it correct on the first shot or it shuts itself down.
 

anthonys735

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Jan 29, 2004
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$5500 is cheap for a boiler, good for you.

That's why we don't mess with them. No margin, especially for the amount of callback associated with getting it nailed in to the customers wants.
 

catlanta33

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I'm an Ecobee honk. Put sensors where the temps vary the most and it does a good job of finding the middle.

Never dealt with their support and they're seldom spec'd for apartment IOT. But, no complaints from personal use.
 
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BMoore2

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Nov 22, 2017
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I don’t have one of these internet connected thermostats but mine reports the temperature where it is located in the house
Honestly, stick with what you got. It’s worth the extra $150-200 a year in utility costs to have heat at all times.
 

Tinker Dan

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Jan 31, 2006
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When performing basic troubleshooting, initially evaluate change.

Is the thermostat also new or are you still using the old unit? Have you verified if Nest is compatible with your thermostat? Was the previous wiring also 3-wire?
Back in my troubleshooting days (not HVAC stuff) my first question was always “who was the last person to touch it?”