For those with a Nest thermostat...

[Krauts]

Before I give up on this new nest thing, I wanted to post the issue to see if were doing something wrong or it's just a very sensitive device.

It's still learning as we've just moved in a few weeks ago. We use both our phones to help with the auto home/away features. The issue is cooling. For example right now it's target temp is 73 degrees in cooling mode. It gets rather stuffy in the house but still says the current temp is 73 and the target temp is 73. If I click down to 72 it says will be 72 in 2 hours, then I set it back to 73 and it says will be 73 in 1.5 hours. So now the AC is on and the house is getting cooler, but the target temp is still the same 73.

thoughts?

 

[ant.foste]

They're hit or miss. I'm on a few HVAC message boards and the amount of services calls and repeat problems caused by the Nest, and solved by replacing the Nest with a Honeywell is much higher than acceptable.

I would not put the first generation Nest, nor this generation of Nest in my own home. There are much better options out there.

 

[Krauts]

I am tempted to just go back to a programmable one. Atleast you know the temp will be xyz at said time on said day.

 

[LS6 Tommy]

The Nest doesn't run to the set point. It lets the space get about 1° F above the set point before it starts the system, then shuts it off when your back to 1° F above the set point, but continues to run the fan for a short period. If you mess with the programming long enough you can usually get it to the "sweet spot". Another reason I don't like Nest stats.

It shouldn't take anywhere near the indicated time to drop 1°F.

Tommy

 

[DenisG]

I'm not familiar with the Nest system, but some temperature controller have an adjustable (programmable) "deadband". Others are factory set:
http://greenpsf.com/pub/ways-to-save/details/Adjust Zone Temperature Deadband/Energy Efficiency

 

[LS6 Tommy]

The Nest has what they call a "maintenance band" that is not adjustable. IDK why I didn't think to add this to my other post, but I know of a few people that refused to swap the Nest for something different, so they added an app called "ThermoTweak". Some of them liked the results. Others felt it just added too much complexity.

https://toomuchsmart.com/thermotweak/

Tommy

 

[yeldogt]

The other problem with playing around with AC is humidity -- unless the system runs long enough and removes the humidity you will not feel comfortable. The people I know that have them bought them because of the ability to turn vacation homes on and off -- those that let them do there thing seem to like them.

But, they are only as good as the system they control -- is your Ac oversized?

 

[Jazz1]

Don’t k ow anything about the Nest other than the wife got it supplied and installed FREE through a gov’t energy program

 

[Trey T]

The Nest doesn't run to the set point. It lets the space get about 1° F above the set point before it starts the system, then shuts it off when your back to 1° F above the set point, but continues to run the fan for a short period. If you mess with the programming long enough you can usually get it to the "sweet spot". Another reason I don't like Nest stats.

It shouldn't take anywhere near the indicated time to drop 1°F.

Tommy

My nest (3rd gen) does it and my home is very comfy, 75degF @ about 45%RH.

the 1degF difference is negligible because an ideal comfortable home will have temp varying 1-2degF from side of the house to another.

 

[tedo2007]

I like my nest. Almost everything is adjustable and you may have a humidity issue in the home. My nest has payed for itself probably twice in the last two years. Going forward I’d probably get something directly compatible with my Samsung smart things instead of having to side load **** on the smart things api to get a device handler.

I think when the garage gets a furnace I’ll probably move the nest to the garage and get something better for in the house.


Sent from my iPhone using Tapatalk

 

[Trey T]

I am tempted to just go back to a programmable one. Atleast you know the temp will be xyz at said time on said day.

what's the relative humidity level (look at nest) in your home when it's 72-73degF?

 

[Trey T]

Don’t k ow anything about the Nest other than the wife got it supplied and installed FREE through a gov’t energy program

Nest is probably one of the cheaper tstat out there. I got mine from a utility company for $150ea when the 3rd gen came out.

I like mine and it gets the job done. If you got the money to burn, I believe the Ecobee has better feature and functions, but I don't know else it will make my home more comfortable.

I have a 2-story home and I was able to optimize my systems, reconfiguring the HVAC systems, with the help from data I collected from nest. w/o the history runtime log, I couldn't tell if my system were running in pair or not. At one point, my upstairs would run about 5-8hrs more than the downstairs per 24hrs. Now it's a lot better - see photo attached

 

[Krauts]

inside humidity is 52% at 73 degrees

 

[Trey T]

In order to lower the humidity, that machine has to run longer but the air flow rate needs to slow down. Call a good HVAC tech (one that understand air flow) to come in and do a quick evaluation to see if he can make adjustment to the blower setting and confirm that the system can be ran properly at those settings.

52% @ 73degF, I can see why you want to push it down to 72degF. If your system can be tweaked like my suggestion above, you can bring the relative humidity down below 50% and be comfortable at higher temperature.

 

[lowe.joshua51]

I have a nest and I like it, as far as I can tell the Nest won't let the AC come on for just a minute or two then shut off. So if you change it to a lower temperature then change it back it's going to run for awhile just so it's not short cycling. As far as the estimated time thing, I'm not sure why it's so long on yours but mine is highly accurate.

I also don't use the auto schedule. My wife and I have an very predictable schedule so I just put it in manually and set it to pre-cool/heat. It's always at my set point as soon as I get home. It adjusts when it starts pre-cooling based on outside temperature and I'm sure other factors.

My AC I think is over sized (it was put in before I bought the house) so the ac only runs 3-5 hours a day on a relatively warm day. Because of this I bought a standalone dehumidifier and that made all the difference.

 

[LS6 Tommy]

My nest (3rd gen) does it and my home is very comfy, 75degF @ about 45%RH.

the 1degF difference is negligible because an ideal comfortable home will have temp varying 1-2degF from side of the house to another.

I realize location has a lot to do wit hit, but 75° would not fly with the locations I service. I'd get "no cooling/not cold enough" calls all day long.

1° difference at multiple locations in the same building not the same as not reaching set point at the t-stat. Normal stats and better smart stats actually reach the set point. Nests do not.

Tommy

 

[graffix000]

I realize location has a lot to do wit hit, but 75° would not fly with the locations I service. I'd get "no cooling/not cold enough" calls all day long.

1° difference at multiple locations in the same building not the same as not reaching set point at the t-stat. Normal stats and better smart stats actually reach the set point. Nests do not.

Tommy

I have a nest and do not have any issues with it, but also have it set up on a schedule. Been amazed at the savings throughout the year.

The newer version three nest's have the ability to place sensors in multiple rooms similar to the ecobee system. This would alleviate the above issue with different rooms. The different temps in different rooms could most likely be addressed by adjusting the airflow. would just take time to do it properly.

 

[Trey T]

I have a nest and do not have any issues with it, but also have it set up on a schedule. Been amazed at the savings throughout the year.

The newer version three nest's have the ability to place sensors in multiple rooms similar to the ecobee system. This would alleviate the above issue with different rooms. The different temps in different rooms could most likely be addressed by adjusting the airflow. would just take time to do it properly.

and skills to balance the airflow. If anyone want to balance the air temp in their home, I highly recommend you spend some money and get a anemometer (3-4" diameter fan type) to chart down the velocity changes. I wouldn't even mess with those sensors - it just do not make sense to me one bit.

 

[LS6 Tommy]

Having remote room sensors that maintain only the room currently being occupied works for energy savings when the remote areas are smaller than the location of the main stat. The real way to do that is to have a balanced, constant volume system that has dampers controlled by zone stats with a bypass damper. It's irrelevant anyway, as the OP's issue has nothing to do with remote sensors or a difference in temperature across multiple rooms. A Nest does not maintain the programmed set point because of the software that controls the "maintenance band". The current versions will never do that. The built in "maintenance band" software only allows them to bring the area to within 1° F of the actual set point. A side effect of that programming is that the system doesn't run long enough and the building does not get proper dehumidification, so even when the room temp is supposedly at the set point, it still doesn't feel "right".

Tommy

 

[Showkey]

On other NEST posts I have commented that the NEST does not play well zoned ducting. So it also has an issue with being a master control with slave thermostat.

I gave up and went back to a more conventional programmed stat.

 

[Trey T]

On other NEST posts I have commented that the NEST does not play well zoned ducting. So it also has an issue with being a master control with slave thermostat.

I gave up and went back to a more conventional programmed stat.

can you detail that? Is the NEST too basic?

 

[Showkey]

can you detail that? Is the NEST too basic?

From other forums I learned the limitation of the some zoning systems and the NEST are known issues. NEST tech support not volunteer the info its what I learned with the install.
My issue was the zone controller did not like the NEST. The newer zone controller was the fix. But add the cost of the NEST and cost of the zone controller then benefits of the NEST did not justify the costs.

As for as the master/slave issue it was my understanding more than one NEST is OK ............a NEST and simple non nest slave was not workable. Two $200+ stats was again techy cool but cost effective.

 

[Trey T]

I'm still not following, in regards to the master/slave control. What are you trying to do or achieve?

I have two system for my home. One point in time, there was only one Nest tstat (downstairs) and one regular Honeywell programmable tstat (upstairs) and both of my systems were able to achieve the adequate comfort level. Another word, they worked fine.

There's something obvious I'm not understanding...

 

[Showkey]

Sounds like your system has two stats with no actual zones.
My setup is two stats with ducted zoning on one furnace ac unit in ranch home witha full basement. If the main section of the home calls for heat or AC and the bedroom room wing does not there is no air flow to the bedrooms.
In the zone controller itself the only one of the stats can set system for heat or cool function. The slave stat can not set heat or cool.......it just turns the system on at set temps ( at what ever function is set by the master).

I did not build the system it came with the home. This system works and it will allow two distinct zones with as much variation in the zones as desired. The guy that build the home and the HVAC spent some real money to get this to work. The home also has furnace in the basement that is stand alone with its own stat completely separate from the other unit.
We especially like the bedroom wing much cooler than the main rooms.

My last home was a large long ranch that had two complete HVAC systems to zone the home. That two of everything was expensive but also supplied great zone control.

 

[jd_1138]

I love my Nest E. Works fine. I just set it and forget it. I don't pay attention to the stuff about "will be 72 in 2 hours" or whatever. If you have good airflow in your system, it should work fine.

 

[KinzeMech]

Mine works great, but from day one I've had it's "auto-learn" function turned off. I set schedules and use the phone app to make changes. My only complaint is that it sometimes has power supply issues without a ground wire to the unit. If it has an issue, I can resolve it by repurposing the out of season wire (heating/cooling) to be a common wire, and the issue goes away. I then have to change it back when seasons change. Long term, I need to run another wire, or a whole new cable.

 

[lkempf]

I have 2 of them and love them both. I have the learning function turned off, and just use the "schedule" feature to set it the same way as programmable tstat. I have had them 2+ years and have had no problems.

 

[Trey T]

Sounds like your system has two stats with no actual zones.
My setup is two stats with ducted zoning on one furnace ac unit in ranch home witha full basement. If the main section of the home calls for heat or AC and the bedroom room wing does not there is no air flow to the bedrooms.
In the zone controller itself the only one of the stats can set system for heat or cool function. The slave stat can not set heat or cool.......it just turns the system on at set temps ( at what ever function is set by the master).

I did not build the system it came with the home. This system works and it will allow two distinct zones with as much variation in the zones as desired. The guy that build the home and the HVAC spent some real money to get this to work. The home also has furnace in the basement that is stand alone with its own stat completely separate from the other unit.
We especially like the bedroom wing much cooler than the main rooms.

My last home was a large long ranch that had two complete HVAC systems to zone the home. That two of everything was expensive but also supplied great zone control.

OHHHHHHHHH.... you got motorized dampers w/ damper controller to create the heating zones. OKAY - i got it.

Never have to integrate Nest w/ another controller ... that's a different topic though

 

[Krauts]

If you go back to regular schedules which is what I'll end up doing, what am I gaining out of the nest besides being able to check from my phone and some reports?

 

[Showkey]

If you go back to regular schedules which is what I'll end up doing, what am I gaining out of the nest besides being able to check from my phone and some reports?

Not much............that’s the problem with the $250 tstat.......there is no payback.

It could be worse.......guys are putting high end thermostat on garage heaters where a $10 unit works and is reliable as a hammer.

 

[tec508]

I don't use the "Learning" feature on my Nest stats. I know that's their selling point, but I don't like anything guessing what I need/want. Same reason I don't like auto headlights, wipers, etc.. on my truck.

As a scheduling thermostat it's on point for me, everything works as it should, looks nice on the walls and integrates with my home automation system perfectly.

I do recognize why a lot of people have problems with them. I think half of it is the design is supposed to be "simple" and that leaves a large percentage of users (and installers) with unrealistic expectations. It's also what happens when IT people make something for the HVAC world.

my $0.02

 

[Renfrick]

I’ve been installing and using nest for years. It’s good stuff. For zoning with dampers just swap out the panel for a hz panel. If you dont have a c wire you can use the g wire and jump. y/g at the panel. Most people do t use the fan feature anyway.
If nest is wired correctly 99.9 % of people have no problem.


Sent from my iPhone using Tapatalk

 

[eddieK]

The Nest doesn't run to the set point. It lets the space get about 1° F above the set point before it starts the system, then shuts it off when your back to 1° F above the set point, but continues to run the fan for a short period. If you mess with the programming long enough you can usually get it to the "sweet spot". Another reason I don't like Nest stats.

It shouldn't take anywhere near the indicated time to drop 1°F.

Tommy

Similar to adaptive intelligent recovery, the Nest has a learning feature to find the target temps / recovery time, this causes more problems than it solves and on the Nest ( verses every digital Honeywell stat out there), you cannot fully lock out the "feature".

 

[eddieK]

i don't use the "learning" feature on my nest stats. I know that's their selling point, but i don't like anything guessing what i need/want. Same reason i don't like auto headlights, wipers, etc.. On my truck.

As a scheduling thermostat it's on point for me, everything works as it should, looks nice on the walls and integrates with my home automation system perfectly.

I do recognize why a lot of people have problems with them. I think half of it is the design is supposed to be "simple" and that leaves a large percentage of users (and installers) with unrealistic expectations. It's also what happens when it people make something for the hvac world.

my $0.02

^^^^ this ^^^^

 

[LS6 Tommy]

Similar to adaptive intelligent recovery, the Nest has a learning feature to find the target temps / recovery time, this causes more problems than it solves and on the Nest ( verses every digital Honeywell stat out there), you cannot fully lock out the "feature".

Exactly. I have three zones of baseboard. All three use the same Honeywell El Cheapo digital 5 day/2 day stats with adaptive recovery. After the second day, my first and second floor zones were at set point when my feet hit the floor in the morning without having to set the occupied time way ahead. They do get a little out of sync when there's a string of warmer or colder days once in a while.

Tommy

 

[Trey T]

I don't use the "Learning" feature on my Nest stats. I know that's their selling point, but I don't like anything guessing what I need/want. Same reason I don't like auto headlights, wipers, etc.. on my truck.

As a scheduling thermostat it's on point for me, everything works as it should, looks nice on the walls and integrates with my home automation system perfectly.

I do recognize why a lot of people have problems with them. I think half of it is the design is supposed to be "simple" and that leaves a large percentage of users (and installers) with unrealistic expectations. It's also what happens when IT people make something for the HVAC world.

my $0.02

^^^^ this ^^^^

I don't use it either because it doesn't work well.

Needless to say, it's a convenience feature and it's very typical that convenience features tend not to be under-control, or can be a runaway train. I mean .... it's the world we live in w/ all sorts of gadgets at our finger-tip.....

However, I don't agree w/ the "IT people" in "HVAC world" - that's nonsense and quite political. I believe people should join hands to make progression but not all progressions are good - most are bad.

 

[eddieK]

I don't use it either because it doesn't work well.

Needless to say, it's a convenience feature and it's very typical that convenience features tend not to be under-control, or can be a runaway train. I mean .... it's the world we live in w/ all sorts of gadgets at our finger-tip.....

However, I don't agree w/ the "IT people" in "HVAC world" - that's nonsense and quite political. I believe people should join hands to make progression but not all progressions are good - most are bad.

It's not politics...It's trade knowledge (heat anticipation - in system control). IT is great - until they step into an area they do not fully comprehend.

 

[LS6 Tommy]

"Internet/Telephone people" don't have anything to do with the design of HVAC controls.

Tommy

 

[Trey T]

It's not politics...It's trade knowledge (heat anticipation - in system control). IT is great - until they step into an area they do not fully comprehend.

It is politic when you label all computer/electrical engineers as IT's, whom are likely the ones to design them. All engineers have the background in fluid dynamic and thermodynamic, which are the bulk of HVAC. So to say that they're not qualified to be in this "area" is a policy matter .... aka politic.

I was gonna quote Tommy ... but it's getting silly. The point is, we should keep the subject productive and meaningful.

 

[lamywaby]

I don't use the "Learning" feature on my Nest stats. I know that's their selling point, but I don't like anything guessing what I need/want. Same reason I don't like auto headlights, wipers, etc.. on my truck.

As a scheduling thermostat it's on point for me, everything works as it should, looks nice on the walls and integrates with my home automation system perfectly.

I do recognize why a lot of people have problems with them. I think half of it is the design is supposed to be "simple" and that leaves a large percentage of users (and installers) with unrealistic expectations. It's also what happens when IT people make something for the HVAC world.
nest thermostat not heating at night
my $0.02

Hi, I'm hoping that someone can help me. A while ago my brother decided to install a nest thermostat. He replaced the old thermostat on the wall with the nest but that's as far as he got as he didn't feel confident to install the heat link. I had some time on my hands so decided to help him out. I've installed the heat sink and it all works grandly. The only issue I'm having is that the wires where the old thermostat was placed don't seem to be providing power to the nest thermostat. In fact, they don't seem to be connected to the boiler at all. I didn't see the wires when I was connecting the heat link. They're not live so I don't know, I'm confused as to how the old thermostat was functioning as I can't locate a relay box to the boiler or anything. Any possible explanation or advice would be very much appreciated. Of course, he could just get a stand for it but it seems a shame to have the location of the old thermostat go to waste.