New furnace/ac install and something isn't right

[jimbofoxman]

Thermostat:  Nest 3rd Gen Learning

So I just had a new furnace and ac condenser installed.  Old furnace was a Comfortmaker of some sort from 2000 and an Williamson AC Condenser from 1973.    The new setup is a Trane S9V2, 96% Efficiency, 2 stage with variable speed ECM blower and a Trane XR16 3 ton 16 seer air conditioner.  Filter went from a 1x20x25 to a 4x20x25.

Something seems amiss.  Yesterday they got in up to at least have AC for the night and came back today to add humidifier, in/out vent for furnace heat to outside, etc.  Yesterday afternoon when they started the unit up, the house was 85° (according to the nest) and it was 98° outside.  In less than an hour it had dropped to 81°.  It wasn't until 9/930 that it got down to 75°.

Today when they left it was 76 in the house at 430 and 89 outside.  By 530 it was up to 77 in the house and it wasn't until 720ish that it was back down to 76.  I even put at thermometer in one of the floor vents and it was blowing 51°.  Humidity is down to 45%, which is better than the old unit.  But I think the old unit got the house colder way quicker.

It is only using 6 wires, is that to few for a multi stage, variable speed?  I haven't even heard a speed change.

I have Y1, G, W1, C, * and Rh

Thank you for any thoughts in advance.

[EdwardT]

Hi jimbofoxman,

Thanks for reaching out. I'm sorry to hear that you're having an issue with how fast your system reaches your target temperature. Based on the wiring that you shared, it appears that your Nest is not configured for a multistage system. Also, could you check if the Nest Thermostat is reading the temperature of the room correctly by using a thermometer?

You could also click on this link to learn more about this.

Thanks,

Edward

[jimbofoxman]

I think it is readying right.   I did put a couple thermometers out and they all seem to be close to each other.  Yesterday morning I reset the whole thermostat to new since it's all brand new equipment.  It was strange again yesterday afternoon/evening.  Guessing my offset ins +/- 1°.   When set to 74° the AC kicks on at 75° and turns off at 73°.  For approx. 4-5 hrs yesterday (outside temp high of 92, 88 when it shut down) it sat at Cooling to 74°.  It would change all the time with it's estimate to cool down.  Which is understandable since I reset it and it needs to learn.   Seems like if it was properly sized and working right it wouldn't take that long to cool to 74 (or 73 by the offset).  Tonnage didn't change.  I'll have to call and see what the installed can do.

[EdwardT]

Hi jimbofoxman,

Thanks for the response. Does the Nest Thermostat cycle your system while cooling? Also, could you check the power reading of your Nest Thermostat by going to Settings > Technical Info > Power.

Thanks,

Edward

[jimbofoxman]

Cycles as in turns in on and off as needed?  Yes, it all seems to work fine until in gets really hot during the day, then it seems to struggle to keep up compared to the older unit.  

Only thing power I see, at least through the App is Battery which is 3.9V.  Was doing some reading before responding.  I don't see anything about Voc, Vin, Lin readings.  They were messing with the C wire the second day here.   Think they hooked something up wrong when adding the humidifier because all of a sudden the stat didn't have power.  It did the first day, then after humidifier added it didn't.

On the Technical info tab all I see are;

Model:  Display-3.4
Backplate Model:  Backplate-5.3
Serial No: long number
Updated:  Never (probably because of factory reset)
Device ID:  long number
Software:  6.2-27
Wifi MAC:  long number
IP:  192.168.1.17
Last Contact:  Just Now
Battery:  3.9 volts.

[EdwardT]

Hi jimbofoxman,

Thanks for the response. The battery level looks normal. Just to clarify, is Voc, VIn and Iin blank? 

Thanks,

Edward

[EdwardT]

Hi jimbofoxman,

It's me again. I wanted to check back in to see if you have other questions and concerns. Feel free to let me know if you do. 

Thanks,

Edward

[jimbofoxman]

So the app didn't show any voltages.  So on the thermostat itself I found;

Voc 35.65V
Vin 35.65V
Iin 200mA(c)

I think the thermo is ok, I do wonder about not having a 2nd stage wire and the fact that it can't keep up on hot days.  What's also interesting is if I just kick the fan on it's at a super low speed.

So I guess I got some questions for the installer.  Thanks for the help.

[EdwardT]

Hi jimbofoxman,

Thanks for the update. The power reading looks fine and it's also recognizing the C wire. Please let us know once you get more information from the installer.

Thanks,

Edward

[Tbauerx25]

Hi Jimbofoxman,

I was searching Google and came across this post.

I had the same ( Trane s9v2 and XR 16 ac unit) installed in March. The installers were not able to test the AC unit  because it was too cold. 

When turned the AC on for the summer, I have been experiencing the same issues as what you have mentioned. 

I had the installers come out and the capacitor needed to be replaced. The refrigerant was also low (installers said every so often they run into a unit that is not fully charged). However, I was still having issues and had the installers come out again. They  had accidentally overcharged the AC which caused the gages to malfunction. 

The AC has been running today and I am still seeing the same issues.

I am interested in knowing if you were able to get the issues resolved and what was the root cause.

[EdwardT]

Hi Tbauerx25,

Thanks for letting us know. I'm sorry to hear that you're also having the same issue. Could you tell us more about what's happening? How long does it take for your AC to reach your target temperature? Also, how is your Nest Thermostat wired?

Thanks,

Edward

[Tbauerx25]

Hi Edward,

My Nest thermostat is using the following wires (Y1, G, W1, C, and RH).

On hot days (85 to 90), I set the thermostat at 70 to 71 and it ran for 5 to 6 hours to cool the house by 1 or 2 degrees. On one of the days overall usage was 20 hours. What happens is the temperature on the thermostat bounces around. For example, the inside temperature went from 72 to 73 to 74 then back to 71 or 72 while it was cooling (never reaching the set temp of 70 or 71 and temperature rising). The system will finally reach the set temp in the middle of the night when the outside temperature drops. 

[EdwardT]

Hi Tbauerx25,

Thanks for the added information. We'd like to know more about this. Please fill out this form so we could investigate further.

Thanks,

Edward

[EdwardT]

Hi Tbauerx25,

Just checking back in. Were you able to fill out the form? Let us know if you have questions and we'd be glad to help.

Thanks,

Edward

[EdwardT]

Hi Tbauerx25,

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 in 24 hours.

Thanks,

Edward