I have a feeling nest wasn't wired correctly.

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  #1  
Old 12-30-20, 03:53 PM
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I have a feeling nest wasn't wired correctly.

We recently had a nest thermostat 3rd gen installed and I don't think it's programmed/wired correctly.

We had our HVAC system replaced 2 years ago and I was told we have a 2 stage heat pump and 2 stage electric heat unit.

The unit numbers are HRG1660S1M and HCG60V1M-1.

I have no idea how the previous thermostat was wired but the person who installed the nest seemed worried when we told them how much our electric bill was during the winter, he said it sounded like the heat pump was not coming on, only the heat strips. He set up the nest and left. We had to call him back because only cold air was blowing (I could hear the outside unit on). After he adjusted a few items the heat came back on and that was that. Now I don't see the outside unit coming on. I touched the copper pipes coming out of the unit after the vents were blowing hot air and they were ice cold.

Below are pictures for current nest wiring, outside unit wiring and diagram, attic unit wiring and diagram.
Since he said we have a 2 stage heat pump with 2 stage electric heat, I asked we the jumpers for w1-w2, o-r-ds and y1-y2 were still on, he said they need to be installed for relay delays and that they don't come on all the time.

Anyhow, if someone can confirm if this is correct or not I would really appreciate it!


Current Nest Wiring

Outside Unit Wiring

Outside Unit Wiring Diagram

Attic Unit Wiring and Jumpers

Attic unit Wiring Diagram
 

Last edited by evigil; 12-30-20 at 04:08 PM.
  #2  
Old 12-30-20, 07:15 PM
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Hi, good model numbers , who is the mfg.?
 
  #3  
Old 12-30-20, 07:39 PM
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There is nothing on Nest's OB connector so it is not running as a heat pump, only AC. The O (orange) is jumpered to R at the air handler to lock out the heat pump function. The outside unit has nothing on Y2 so only running single stage.

Find a new tech.
 
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Old 12-30-20, 08:09 PM
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Welcome to the forums.

Comfort Air

I hope that was a friend and not a tech. If it's a tech..... fire him.
Your heat pump system is not wired as a heat pump system.
I see several major issues here.

You do have two stage electric heat but I think it should remain as single stage.... as it currently is.

At the stat....
Connect orange to O/B.
Move white wire to W2/AUX (program nest for heat pump with aux heat)
Move black wire to the * terminal. (program * for emergency heat.)
NEST: Two stage heat pump with aux heat. Two stage cooling.

At the air handler.......
Leave the jumper on W1 to W2.
Remove the R to O jumper. (this jumper keeps heat pump locked in cooling mode)
Remove Y1 to Y2 jumper to engage two stage cooling.


60k air handler installation manual (pdf)
5 ton condenser installation manual (pdf)


@ astuff...... took me 45 minutes to wade thru this.
 
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Old 12-30-20, 09:35 PM
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Thanks for the replies!

The Y2 wire (brown coming from attic) has a wire nut with the light blue (at outside unit), and is not terminated on a screw.

Yeah, I don't think this guy will be coming back... I'll make the changes suggested in the morning and let y'all know if that fixes issues, I really do appreciate the help!

 

Last edited by evigil; 12-30-20 at 09:37 PM. Reason: Added more info.
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Old 12-30-20, 09:38 PM
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Yes..... out at the condenser. That is correct.

Be sure to kill the power to the air handler before changing wiring.
 
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Old 12-31-20, 08:47 AM
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I made the changes as listed above and it appears to be working properly now. I do have 2 questions that came up on the thermostat when I was setting it up:

Use the heat pump compressor when the outdoor temperature is above: the default is "always". Should I change it?

and

Use the heat pump auxiliary heat when the outdoor temperature is below: the default is 50*.

Below are the new changes:


New nest settings

New nest wiring
 
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Old 12-31-20, 06:46 PM
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Use the heat pump compressor when the outdoor temperature is above: the default is "always".
Should I change it?

Use the heat pump auxiliary heat when the outdoor temperature is below: the default is 50*.
Are you new to a heat pump system ?
Typically a homeowner will know the point where the heat pump no longer works effectively.
If you set it to always it will never shut off no matter how cold it gets. Knowing the lowest effective temperature of the system can guide you. The aux should only come on when the heat pump can't keep up.
 
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Old 01-02-21, 10:45 PM
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Yes, our last HVAC system did not have a heat pump system. I will check to see if the guidelines to set the temps is in the manual. Thanks!
 
 

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