Nest wants a y1 cable since yesterday. I don’t have a y1 cable.

[Cbusch]

Hi, I have a nest for five years connected to a gas furnace. It’s been working fine all those years.

Since yesterday it complains that it wants a y1 cable. There is no y1 cable and there never was. 
It looks like it now thinks it’s connected to a heat pump while it’s in fact it’s still connected to the gas furnace. 

Cables to Rc Rh W1 C

any idea how to fix this? 

[AxelD]

Hi Cbusch,

Thanks for posting and sorry to hear about this situation with your Nest Thermostat. No worries, help is here! Please try the next troubleshooting steps:

1.  Remove the RC wire
2. Perform a Factory reset on your thermostat. Here you have the steps to do it Restart or reset a Nest thermostat
3. Set it up again

Try all these steps above and let me know how that goes. 

Regards,

Axel. 

[Cbusch]

Still weird.

i used to have furnace cables to w1 and Rh. Then a wall psu to c and rc. 

I found a nest manual that says put power to c and RC. Then hookup w1. But i have the second furnace cable that used to go to Rh. What do i do with that? 

[AxelD]

Hi Cbusch,

Thanks for your reply, Based on that information, you don't need to connect the RC wire because you don't have cooling. It should be enough to only leave connected W1, RH, and C. Also, can I get a photo of the C wire? 

Regards,
Axel. 

[Cbusch]

Alex,

"can I get a photo of the C wire?"

>> Sure but how do I upload a photo here? I would have done that but there doesn't seem to be an option to upload anything. 

[AxelD]

Hi Cbusch,

No worries, I only wanted to take a look at your wiring. Please try the recommended wiring in the post above and let me know how that goes.

Regards,

Axel.