Thermostat Detects Yellow Wire

[bespinct]

My Nest Thermostat detects a Yellow Wire when there is not one present.  There is only an LP furnace, forced hot air.

There are only three wires, Red - Green - White.

Lines are connected to, RH - G - W1

I think sensing the Y wire has it believing that it also has a cool setting.  Currently, the cool setting turns the heat on and the heat setting does nothing.

Does anyone have thoughts?

[Patrick_Caezza]

Which Nest thermostat do you have?

 Heat-only systems require a C wire to work correctly. It could be miss reading which terminals have wires inserted in them

[Jenelyn_O]

Hi there,

@bespinct, chiming in — I just want to follow up, could you please provide the information asked by Patrick_Caezza? Also, share with us the photo of your current wiring and the photo of the wires connected to your control board. It will help us to move forward. 

Thanks for your help @Patrick_Caezza.

Best,

Jenelyn

[Jenelyn_O]

Hi there,

I wanted to follow up and see if you still need help. Please let me know if you are still having any concerns or questions from here, as I would be happy to take a closer look and assist you further.

Best,

Jenelyn

[bespinct]

It seems I was distracted and did not hit reply to my last post.

I was able to address the issue.  It seems that the Y sensor believed there was a wire inserted.  I remove all wires, inserted a wire into the Y spot, pushing it in and out a few times, then rewired properly.  The Y sensor no longer showed a Y wire connected and following a rest of the thermostat, it behaved as expected.

[Jenelyn_O]

Hey bespinct,

Woohoo! I'm glad to hear that your issue is already fixed and thanks for the update. I'm going to lock this thread in 24 hours. If you have any other concerns or questions, please feel free to create a new thread.

Best,

Jenelyn