Nest Thermostat, Wiring for 3rd generation, 6 wires, w/Heat Pump. W1 or W2/aux?

[MacJW]

I'm actually hooking up two Nest thermostats. Upstairs and downstairs, each with their own heat pumps. Both have White-Rogers thermostats but they're different. They both have the same 6 wires. The main floor is programmable the upper floor is not. The upstairs Nest is 3rd Gen, the main floor will be 4th Gen.

All of these wires make sense Y1, G, O/B, Rc or Rh, and C.

I have conflicting information about W. I have a heat pump for each floor. When it gets very cold it uses an Auxiliary mode within those pumps. Single source. Currently, in both devices, the white wire goes to a location named W2. There is no W1 in either box. On the upstairs box there's a jumper wire from W2 to E. I realize this is a naming convention but I think it is for a reason.

When I go through the Nest setup it tells me to put the white into W1. But there are many articles and explanations saying that is incorrect. It needs to go into W2/aux. I don't want to wire this incorrectly as it will be the same for both Nest devices assuming 4th generation will be the same setup as 3rd.

On the upstairs box there is a setting called Emer. The downstairs just automatically kicks to Heat Aux when it can't keep up. I assume these are using the same coils in the heat pumps but the manual one needs to be told.

I would appreciate confirmation of the wiring. Much appreciated.

[Patrick_Caezza]

@MacJW 

When you have a heat pump, the W wire is normally for AUX heat, and you put it in the W2/AUX terminal.

Post a picture of both original thermostats' wiring, and I will verify the wiring for you.

If the camera icon isn't present yet, you can use the imgur.com upload site and post the link it provides here.

[MacJW]

 

 

[MacJW]

Sent the pictures as requested. Hello?

[Patrick_Caezza]

@MacJW 

Give this a try for both thermostats,

Red - R to Rc

Orange - O/B to OB

Yellow - Y to Y1

Green - G to G

Blue - C to C

White - W2 to W2/AUX (set as AUX heat)

[MacJW]

I hooked it up as suggested. Unfortunately the green wire would not reach. I went to Home Depot and purchased 1 foot of thermostat wire. I used a couple inches and extended the green so it would reach to the slot. I powered it up and it appeared to work. Set it up with my internet. It updated the software. Everything looked good. It was still set to stay between 68 and 76. I came back upstairs a few hours later. It was 86 F ! It showed as cooling but heat was coming out.

I had read you could change the default O to B in settings and it might reverse it. I did that but it still blew heat while it said it was cooling. Turned it off and opened the windows. Not sure what to do now, Haven't started on the downstairs one.

[MacJW]

In desperation I tried the White wire in W1. It was what the software originally suggested. Didn’t work. Also changed from O to B and had no effect. This thing will not turn the A/C on. I have no confidence the 4th generation will be any difference. The manual White-Roger worked without fail. I love the Nest device but it simply doesn’t work even with exactly the same wire lettering.

[MacJW]

This works. No wifi, no remote control, no slick interface, but when you slide the button to cool, the air conditioner goes on. I don’t see how this can’t work!! The wires are virtually the same letters. I put the white wire back into W2. Restarted the Nest which was a suggestion by some. Turned it to cool and you can hear it kick on. Went outside side to see the heat exchanger going. Came back in, it was up a degree with heat pouring out. Turned it off. It’s beautiful, but it doesn’t work. I’m about done. 

[MacJW]

Reset the device to factory settings. Set it up again from scratched. Added it back to the app. Everything is very lovely which is why I wanted to switch to Nest. After all that it still only provides heat. Set to cool only and it heats. I’ve now read many articles with the problem of not cooling. How can a $200 thermostat, with the same wiring, not send the same signals to the equipment as a $25 one. Please respond as the lack of one makes me feel like there is no resolution and the device is simply defective. And if that’s the case then just tell me so I don’t waste anymore time.

[MacJW]

I’m a bear for punishment so I ordered another wired baseplate. It says it works with all 3rd Gen Nest. Received it; removed my standard manual one, installed the new base; turned power on. What’s particularly annoying is how beautifully it operates. It accurately identified the wires which were identical to the setup on the Gen 4. Unfortunately it didn’t work the same way. Would not produce A/C. Screen said cooling; hot air coming out. Switched from O to B, which has never worked, and true to form continued to blow hot air. 😞 So I’ve truly given up. Read some stories online of the identical problem and the frustration with Nest for not admitting to this defect. My $20 White-Rogers totally manual box works perfectly. As did the Gen 4 with the same wiring. The 3rd Gen simply won’t activate the A/C. So sad.