No Heat Mode

[steve121]

My thermostat controls a set of wall heaters, only. It is a three wire system. I wired it to Y-C-R. The device and the app only allow me "Cooling" mode and "Off". I have attempted to change it to "Heating" through both the device and the app and there appears to be no option. **I can turn my heaters on by dialing the temp to a a low temperature setting but eventually the device tells me that the system is malfunctioning because the "Cooling" is not lowering the temperature in the home.

[Jenelyn_O]

Hi steve121,

Thanks for reaching out. I'm sorry for the delay and for the confusion. The reason why you don't have an option for heating is because you only have 3 wires that only control your AC. You should have wire for the W terminal of the Nest Thermostat to run your heating system. 

This is an example wiring of a conventional system:

• Y - Cooling
• C - Common
• R - Power
• G - Fan
• W - Heating

Please share with us the photo of the wires connected to your system's control board or the photo of the wires that connected to your old thermostat. It will help us to check if you have wires for your heating and for the fan. 

Best,

Jenelyn

[steve121]

App says that I do not have permission to upload photos. Regardless, as stated I am using Y, C, and R. They run a pair of wall heaters, aka 220V toaster-like electric heaters. With current wiring they run fine, except that I have to turn the "cooling" setting down for them to turn on and heat the house. 

[steve121]

So, is there a way to wire it to make "Heating" the option? How can I resolve the issue?

[Markjosephp]

Hello folks,

I appreciate you for looking into this, Jenelyn.

Thanks for confirming it with us, @steve121. I wanted to stop by and see how I could help. Have you tried checking for a spare wire behind the wall or directly from your system control panel to see how the wires are labeled? Try checking it out and keep me posted if you notice or find anything.

Regards,
Mark

[Markjosephp]

Hi steve121,

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

Thanks,

Mark

[Markjosephp]

Hey steve121,

It has been a few days since your last reply, and we're going to lock the thread within 24 hours. If you have any questions, please feel free to create a new post.

Best regards,

Mark