Nest E Thermostat is WRONG

MonofloMad1

So I installed a Nest E thermostat the other day and it seemed great but I noticed the reading is off the last couple days. Right now it says it’s 74 in my house and there is no way it’s 74. It feels like 63! Does anyone know how I can get this thing reading the temp correctly? It’s actually seems to be going up.... I started noticing it when it was reading 68 and didn’t feel like 68 then got stuck around 70 71. I just did a factory reset and now it’s on 74!! ****! I have it just for my radiant oil heat so only 2 wires connected.... any suggestions?

Zman

Where is it installed. Is there a lighting dimmer or other heat source nearby?

Alan (California Radiant) Forbes

Nest stats are notorious for reading too high a temp.

I keep mine at 72° which in reality is 68°.

MonofloMad1

It’s in a hallway. No light source to cause the heat difference.

HVACNUT

I'm no expert on the Nest, and I dont wanna be, but
Is there a radiant setting on the Nest?
Is there radiant heat directly below the Nests location?
Doesnt the Nest need 24v unless theres a resistor?

The Tekmar 508 is a fine, simple radiant thermostat. It needs 24v and it's not WiFi.
It's not WiFi because you dont adjust a radiant thermostat. Set it and forget it.

Glad to see your taking your mind off the other mess. Any updates?

MonofloMad1

Yes it is a radiant setting.... I’m not obsessed with technology but it was free through PSEG my electric company so I got one threw the old one out and now 🤷‍♀️

ratio

If an electronic thermostat, of any type, shows the same temperature through a cycle or two of heat-on, the screen isn't showing the actual room temp. It's showing an average of the room temp over the last few cycles or something.

Remember, the job of the thermostat is to keep the temperature steady. If it is running the heat, the temp has dropped in the room to the point where the heat can be run without overshooting too far.

Most modern consumer-grade temperature sensors, while only guaranteed to be about ±2° of actual, are quite capable of a 0.1° resolution.

My personal belief is that the more complicated the thermostat, the better chance of it getting stuck somewhere in its calculations.

NB: I dislike Nest stats.

Gordy

I have to ask in light of your other post. Did you get everything else working properly? If not that could have a direct effect to this problem.

MonofloMad1

Yup!! The valve idea worked perfectly!! Slowed the flow in between the t’s forcing it to the radiators. We can even have More control opening the valves all the way if the room too hot and closing it a bit if the room is on the cooler side

pecmsg

NEST is garbage, Power Stealing control. Several complaints of failures. https://www.nytimes.com/2016/01/14/fashion/nest-thermostat-glitch-battery-dies-software-freeze.html
You got it for free so no loss, replace it!

STEVEusaPA

Keep in mind if your utility company 'gave' you the thermostat, you may have also agreed to allow them access to it.

Meaning on the hottest day of the year they may bump you up a few degrees, or hold you off for a couple of hours during peak demand. On the coldest days of the year they may lower your thermostat.

People become unaware of this and call their HVAC company thinking their equipment isn't working properly.

Remember to tell your HVAC company that you have a utility company thermostat on your system.

On a side note, I collected a service call fee and told the customer to submit it to the utility company. But the bigger problem is now, when that customer (or a customer with the same situation) has a problem the utility company wants you to call them first. Now they are notorious for taking a few days to get to you. And if it turns out it's not the thermostat, then that customer has to call you (me) for service.

All for a 'free' thermostat.

MonofloMad1

I don’t know about all that... I definitely didn’t authorize any kind of remote access. They do run programs like that where the take a set amount off you bill for participating but this wasn’t that kind of program. Just a rebate through them funded by some kinda government grant.

pecmsg

This
https://nest.com/energy-partners/pseg-li/

MonofloMad1

Nope

Wellness

I'm sorry for your experience. But for anyone else pondering acquiring this shiny object: The Nest thermostat is the Facebook of boiler controls, and I don't mean that in a good way...

Jamie Hall

I might add to some of the above -- whether or not your power company has retained access to it I do not know. However, be assured that the manufacturers most certainly have, and do monitor it. There's nothing you can do about that, if it's connected to the internet at all. Further, be also assured that unless you have a very strong password, pretty much the whole of the internet has access if they want it -- and there is always someone out there who might...

ChrisJ

If you want a thermostat you can access remotely, I would highly recommend the Honeywell Prestige. It can be accessed remotely and does a whole bunch of other good stuff.

From the sound of it, that's not what you necessarily want though and the Prestige is quite expensive.

If you want a simple, reliable digital thermostat check Ebay for a Honeywell TH8110.

Gordy

Send it back, or put it on eBay if they don’t want it back.....

mikeg2015

“Rea” thermostats allow manual temp correction. The higher end Honeywells all do and so does my Lennox e-comfort. They also control tighter by using cycles per hour (PI control) I think NEST still uses a fixed differential only.... just like a bimetallic strip.... ie 100 year old technology.

duffy_4

There is a lot of issues it seems with nests stats. Just installed 9 3rd gen in SFH 2story all radiant .bsmt ,2zones 1st floor,6zones second floor.home owner selected nests I had no say in it. The two stats that control the air handler (2nd fl) ,furnace/ac (bsmt&1stfl) and steam humidifiers we difficult to wire and get working correctly had to use RIB relays etc.....
Had to sign up and become nest pro to get access to good tech help.
In your case you might need a third wire to the C terminal (common).
With radiant nest take month to learn how to adapt to the environment I was told .
Don’t think I would recommend them !gotta go back to the job again in morning ,homeowner thinks it’s my fault when stat starts doin wacky stuff

SuperTech

My two cents as a service technician:

Steve is absolutely correct about utility company access to changing setpoints. They do it where I live

More nuisance service calls from nest stats than all other combined.

They absolutely suck for hydronic applications for numerous reasons along with the ones mentioned.

You couldn't pay me to put one in my house.

The intelligent part of the heating system should be the owner, not the device switching it on and off.

Voyager

HVACNUT said:

I'm no expert on the Nest, and I dont wanna be, but

Is there a radiant setting on the Nest?

Is there radiant heat directly below the Nests location?

Doesnt the Nest need 24v unless theres a resistor?



The Tekmar 508 is a fine, simple radiant thermostat. It needs 24v and it's not WiFi.

It's not WiFi because you dont adjust a radiant thermostat. Set it and forget it.

Wifi is useful for far more than adjusting the temp or programming the t-stat remotely. The main reason I installed Honeywell WiFI t-stats in my church and workshop was to monitor the systems remotely for failure.

Our church had a boiler failure a few years ago and nobody knew about it until it was too late, since the church is unattended most of the time. A pipe burst and had to be repaired in the middle of the night when it was below zero. We had a boiler failure last year and I got an email saying the temp was below my low limit. I was able to get a service tech there before the temp dropped below 50 in the church. That one incident nearly paid for the 5 t-stats.

To me, the remote notification of temps that are out of range is far and away the biggest benefit of a WiFi t-stat.

ChrisJ

I too use my Prestige to keep an eye on things when I'm away.

Jamie Hall

I have no problem with a Wifi thermostat -- hopefully with some sort of alarm system. In fact, I wish they were in some of the other properties I care for. For exactly the reasons @Voyager and @ChrisJ mention. But there are a number of good Wifi thermostats which are just that, and aren't Nests: they don't try to think for themselves and make a mess of things.

But I reiterate my caution: if you have one, make sure that your login is unique, and your passcode is very strong. "admin" and "123456" just won't do.

NY_Rob

If the local utility is giving something expensive to you for free... there has to be a catch 100% guaranteed.


Your utility is in control of your free Nest E stat:
https://nest.com/support/article/What-happens-during-a-Summer-or-Winter-Rush-Hour

TheKeymaster

Nest is garbage. Every hvac guy I've ever talked to say that the only thing nest is good for is making them money when they fail or break something else.

https://hvac-talk.com/vbb/showthread.php?2201161-Should-I-replace-my-thermostat-with-a-Nest-E

GerriHeft

Hello...the interior circuits in your indoor regulator can get hotter in the event that you make a ton of changes on your indoor regulator in a brief timeframe, if the showcase is on for quite a while, if there's a functioning programming download or if different things occurring. This can make the indoor regulator believe that the room temperature is higher than it really is and conceivably defer warming.
So perhaps it was downloading stuff out of sight? or then again you had the presentation on something over the top? I would let it settle down for a couple of hours and do your temperature correlation test once more.

order pcb

BigRob

I had air currents coming through the wall and into the mounting ring of the Nest E. Might not be your issues but it's a consideration.

Leon82

I stuffed a small batt of insulation above and below my thermostat to stop drafts from going into the wall cavity.

Newer houses should have the fire caulk on the nail plates making it draft free